“[…] I smelled what I described at the time, and I still would, as a burned bird smell brought from the engine air into the conditioning system of the airplane.” (Chesley Sullenberger on CBS “60 Minutes” http://www.youtube.com/watch?v=u1LmBHEmr9U)
In order for a pungent odor from a jet engine to fill a cabin there has to be a substantial and steady odorous supply of pungent molecules emanating from the engine. But a bird, even a big goose, passes just too fast through an engine to achieve this. The destructive damage inflicted on the engine from a bird ingestion can certainly result in foul cabin air, but so can a compressor surge which came a whisker from blowing up the right CFM-56-5B4/P engine on Cactus 1549 two days earlier over Newark. A collision with an entire flock of large geese must also produce a series of rapid distinguishable loud thumps, like sandbags. Only one bang was heard on Cactus 1549 and it came from, not the right, but the left engine with no other accompanying sounds.
The air piped aboard modern airliners is second in purity to a modern hospital operating room. Air is supplied by an Environmental Control System (ECS), literally a life support system. The ECS sterilizes and re-circulates cabin air, pressurizes the airframe, replaces all onboard air 3-4 times/hour, regulates cabin temperature, helps power pneumatic systems, supplies the heat for wing de-ice and potable water, keeping all onboard alive in a humanly unsurvivable environment that without everyone aboard would perish.
Occasionally, you’ll hear or read (most likely on an internet forum site) airline transport pilots swear that they smelled the “KFC smell” after a bird ingestion. The trouble with this is that wild birds that fly into jet engines aren’t gussied up in 11 of the Colonel’s secret herbs and spices and deep fried in grease and/or cooking oil to smell a block away. Wild birds aren’t seasoned by a spice rack and there’s no cooking grease/oil in the core for deep frying. We can take such claims with a huge grain of salt.
To offer a time frame perspective on the impossibility of Sullenberger’s bird smell claim, Cactus 1549 was traveling 175kt at the purported bird strike point. At this speed the 8.5’ long CFM 56-5B turbofans were traveling their length in 35 milliseconds or ten times faster than the blink of an eye. At 90%+ N1 on departure power setting both engines would suck any wayward goose through the fan disk and accelerate its shredded legacy through the engine core or bypass at even fewer milliseconds since producing thousands of pounds of forward thrust to propel and climb the A320 that can weight up to 206,000lb on takeoff. Each engine pushes up to 103,000lb through the air in a positive climb, resulting in a massive volume per minute rushing though each engine and much more in 35 or less millisecond time frame than a large goose's volume. A goose would pass through and exit the 8.5’ length in thousands of shredded pieces faster than ten times faster than a blink of an eye and the only time interval that any ‘burned’ goose particulates would be available to contaminate the onboard air supply. For contrast, the leader bolt from a lightning strike strikes in about 20 milliseconds. An ingested bird would, therefore, approach ‘lightning’ velocity through the core and out the exhaust.
The ECS draws air from engine ‘core’ bleed air ports located at the low and high pressure turbine stage and variable geometry ram air inlets on the fuselage bottom between the wings.
The bleed port diameters are mere inches across and to draw in bird particles these would have to pass right over the selected port or ports in use aperture(s).
Chesley Sullenberger’s above statement infers that there’s a direct air supply from the bleed ports to the cockpit and second, at near lightning strike velocity a sufficient concentration of burned goose particles passed over an open port(s) and wended their way to the cockpit unimpeded, up his nostrils, which he then detected and identified as “burned bird” and, coincidentally, only person onboard to do so. Fuggedaboudit!
At takeoff and initial climb the low pressure turbine stage air temperature is 400* F, but its pressure is only 30-40psi, too weak to handle all the needs of the aircraft. So the high port at 1200* F and 430psi handles all the ECS duties until the aircraft achieves sufficient forward speed for the ram inlets to provide adequate air flow. While parked at the gate there is zero functional air flow through the ram air inlets due to zero knot forward speed, so only the bleed ports can draw in air.
The trouble is Jet A-1 auto-ignites at 410 *F, so to avert any fire from a possible fuel leak the high port air temperature is reduced to below 410 *F by a heat exchanger called a precooler. The very first stop for the high port air in the ECS process after entering the aperture at 1200 *F, a temperature that easily sterilizes any living microorganism, is an exhaust that dumps most of the 1200 *F air overboard, my guess is two-thirds, to shed over 800 *F from the remaining air that then travels into the pneumatic manifold. The majority of Chesley’s “burned bird” particles drawn into the high port would be sterilized and then tossed overboard before entering the manifold.
The now sub auto-ignite and still highly pressurized air eventually passes through a centrifuge and coalescer bag that separates water molecules and any heavier than air particle, including goose, and dumps these overboard too.
What are the chances of the high port drawing in goose particles versus the other thousands of cubic feet per second of ‘clean’ air? And how much air can the high port draw in 1/35th of a second?
The Airbus ECS supplies at least 20 cubic feet of air per minute per seat (passenger, attendant and crew) onboard, whether occupied or vacant. 10cf originates from the bleed ports and rams (though just bleed ports on taxi, takeoff and initial climb) added to an existing 10cf/seat of sterilized and recycled cabin air. The recycled cabin air is multiple HEPA-filtered to 99.99% particulate-free and so filter sterilized, and the other half (at takeoff and initial climb) is compression heated sterilized high port air blended with HEPA-filtered cabin air in an air mix manifold, all water-separated and coalesced, which makes the recycled cabin air doubly sterilized and why second in purity to operating rooms. At takeoff the high port handles all the ECS duties of supplying the 10cfm requirement of new air per seat, say 185 seats total, but since two-thirds is dumped overboard by the precooler the high port will draw in an initial 30cfm/seat for a total of 5550cfm (figures not accurate but reasonably close) before two-thirds is soon dumped. This breaks down to 2.6cfm of maximum possible draw of goose particle contaminate air volume of undetermined “bird smell” concentration in the <35 millisecond bird ingestion interval. Therefore, only 0.87cf will survive the precooler dump, already sterilized, then water- and particle-separated, before pumped in even distribution up and down the entire cabin and blended with at least 5550cf of existing uncontaminated air pumped out of the cabin vents at about 500ft/min and deliberately directed away from the face and hands. Sullenberger, and only he, got a whiff of bird, did he?
To smell any odorous contaminant in the cockpit via the bleed air ports the source must originate in the engine core and at a molecular concentration high enough for the human olfactory system to detect would require being apropos to downwind of a barbequed goose or something to this effect. But a 4” long Canada Geese feather was supposedly found in the left engine outer bypass, which it couldn’t have as explained in another article, totally isolated from the core by a hermetically isolated metal boundary and nowhere near the bleed air port aperture for goose particulates to be drawn in, then somehow survive the precooler dump, then centrifuged and again dumped, mixed with 99.99% particulate-free cabin air and then pumped up Sullenberger’s nose and no other’s. Although it is possible for goose material from the same bird to pass through both the core and bypass, the core material would be shredded, pulverized and heat sterilized from the 430psi in the high compressor stage.
What do sterilized goose particles smell like? Probably not much, they've been crushed by 430psi and heated to 1200*F. Every microorganism has been destroyed. Most of the food we eat, including bird, is sterilized. Its taste is not natural, but from synthetic chemical additives simulating the real thing and accurate enough to fool the human olfactory system. Unless the A320 has a cockpit-mounted synthetic bird chemical additive dispenser, Sullenberger would never smell burned bird. To smell burned bird, the bird first has to burn. If you flick your finger through a propane torch flame, will it be burned? Nope. Do bird particles, moving >175kt, have time to burn at 1200*F under 430psi before dumped overboard at the precooler? After many minutes subject to this heat it will, but not in 35 milliseconds even at 1200 *F. What will emit a powerful pungent odour from internal engine destruction are leaking engine seals whose escaping contents 'smoke' under the intense heat and pressure due to a continuous long-lasting supply as directly opposed to a <35 millisecond dosage.
All of the above concerns a functioning turbofan system. The left engine, however, shutdown. Once the shutdown occurred, and after any ingested bird would exit the engine unit, the high port turbine would shutdown, drastically dropping the temperature and pressure, knocking out the water-separating centrifuge and recirculation fans. How do molecules of “burned bird,” sterilized by 430psi to 1200 *F, which incredibly beat out every other cubic foot of clean air in the core to enter the high port, survive the precooler dump and water-separator, wend their way from near mid-left wing to the cockpit by quickly waning turbine power from a miniscule window of opportunity, then overwhelm the powerful stench of smoking engine lubricants and oil in only 0.87cf to pull it off?
I’d say Chesley might want to spice up his statements that he gave to the House Transportation and Infrastructure Committee hearing (in theory) on US Airways Flight 1549.
Saturday, May 9, 2009
Tuesday, April 7, 2009
Defeathering the Cactus 1549 Goose Story
Bird Ingestions Don't Go "BANG!"
“Other passengers on Flight 1549[…] had heard what sounded like an explosion. Elizabeth McHugh, a project manager for a company that installs information systems in hospitals, called it ‘a big bang’. Karin Hill, a college student on her way to Denver, called it ‘a loud thud’.” (NYT, Jan.16, 2009, “US Airways: A Passenger’s Account”)
Engine damaging bird ingestions, as viewable on many a YouTube video, cause a ‘POP!…P-POP!…POP!…POP!...’ effect with accompanying flame burst each time, similar to repeated strikes of a sledgehammer on a steel I-Beam. A completely different effect to a compressor surge where highly compressed air explodes out the intake and exhaust in a one-time extremely loud boom.
A one-time loud engine bang (or thud depending on proximity and discretionary interpretation of audible sounds) heard in the cockpit followed by shooting flame, rapid yaw and vibration is so startling that it can shock experienced pilot(s) into a string of errors. The most prominent of these: failing to continue flying the aircraft, misdiagnosing the real problem and inadvertently shutting down, especially unproductive on a twin engine aircraft, the remaining good engine. It is doubtful that Cactus 1549’s crew committed any of these errors and the point of iterating such is that these encounters are terrifying to any airline transport pilot.
It is known that Cactus 1549, as recorded by its Aircraft Situation Display to Industry (ASDI) data stream (FlightAware.com), committed an unapproved, uncommanded 15 degree left turn course deviation off its assigned 360 degree departure route just south of the Bronx Zoo. The veer strongly suggests that the severe left engine event occurred right here at circa 2800’ at 174kt forward speed that yawed the aircraft off course without detected or acted upon by the Departure controller. A report on Wikipedia alleges that the shutdown occurred at 3200', but this interpretation doesn't account for the preceding course deviation or the total lack of yaw at this presumed 3200' shutdown point. In-Flight Shutdown (IFSD) induces unavoidable yaw as the engine fan disk rapidly decelerates and takes on the attributes of an unconventional parachute while the opposite engine continues to spool at N1 climb setting rpm, inducing an abrupt doubly powerful yaw motion as the dud left engine on Cactus 1549 acted like a brake while the good right engine pulled the right wing forward, forcing the left wing backward, turning the aircraft to port.
After regaining control co-pilot, Jeff Skiles, flying the aircraft, held this 345 heading for the next 3nm. After this veer the aircraft accelerated to 194kt while climbed an additional 400’, likely even higher. The laws of physics absolutely forbid unpowered aircraft to accelerate in a climb, therefore, the right engine must’ve been producing normal forward thrust after the left IFSD at 2800’ before it too eventually shutdown for unknown reason(s). The FAA and NTSB have not released the Flight Data Recorder parameters, rendering all explanation as speculation based on known ASDI, cockpit/TRACON audio tapes and personnel/passenger statements.
Cactus 1549 likely climbed a little beyond 3200’ as the ASDI continued to display a positive climb regimen at 40*51”36’N 73*52”48’W over New York Botanical Garden just east of Southern Blvd, mere instants before 1549 commenced an unpowered ‘deadstick’ descent. A double in-flight engine shutdown would not prevent a brief continued climb but would void any airspeed increase for being physically impossible from no energy supply to produce power to produce acceleration.
From loud bang and shutdown approaching the Bronx Zoo to the Botanical Gardens ASDI update Cactus 1549 traveled 1.85nm in 36.2 seconds at an average speed of 184kt. The right engine continued to work for the better part of this 36.2 seconds. Calling into question a flight attendant’s statement that all engine noise ceased after the initial boom and the cabin fell totally silent “like being in a library.” (Aviation Week “Update-Flight 1549 Inside the Cockpit, Inside the Cabin.”)
18-19 seconds and 1.1nm later TRACON, unaware of the A320’s situation, issued a standard left turn to heading 270* instruction to Cactus 1549 to route the aircraft north of Manhattan and eventually on course to BIGGY over New Jersey. Pilot-in-Command Chesley Sullenberger immediately and verbatim responded: “Ah, this is, uh, Cactus fifteen forty-nine, hit birds, we [have] lost thrust in both engines. We’re turning back towards La Guardia.” TRACON acknowledged Sullenberger and issued a left turn to 220* at 3:27:42PM. Either Sullenberger or co-pilot Skiles (originally flying), since unconfirmed which now, commenced an immediate sharp left bank to 220* beginning over the intersection of Mosholu Parkway and Grand Concourse. All told 55 seconds elapsed from the left engine shutdown to TRACON first learning of 1549’s situation.
Pilots do not dawdle for the better part of 55 seconds before choosing to alert a radar unit of a major midair emergency. What happened in these 55 seconds?
Reasonably inferring from the ASDIs and audio tapes, at circa 2800’, without warning, the left engine emitted a loud boom, the engine shutdown, aircraft abruptly yawed left, and the airframe shuddered, all normal consequences, startling the pilots and all onboard.
But not a sound or flame emanated from the right engine. Birds ingested through the fan disk that destroy the engine cannot damage fan blades, variable stators and static turbines without unmistakable audible and visual indication. The ingestion has to induce a series of abnormal loud popping sounds with accompanying flame burst and/or ignited raw kerosene flaming out the exhaust. Therefore, no geese or any birds could’ve been ingested into Cactus 1549’s right engine or all onboard would’ve heard the unmistakable consequence and most of the right side cabin passengers would’ve seen the flames shrouding destroyed blades forcibly ejected in bits and pieces.
The left engine boom would stun Sullenberger and Skiles, eliciting verbal or silently contemplated ‘What the hell was THAT!’ reaction. The Master Warning siren would blare into action. The twin glass cockpit Engine Indicators/Crew Alert System (EICAS) and Electronic Centralized Aircraft Monitor (ECAM) would broadcast real-time engine parameters and trouble descriptions. N1 and N2 would quickly plummet, with possible, but not necessarily, Exhaust Gas Temperature increase and/or engine fire warning. The startling bang, sounding like a bomb exploding and most pronounced at low altitudes such as 2800’, would draw immediate pilot focus to the EICAS and ACAR while the aircraft yawed, partially banked and shuddered from the natural harmonics of the rapidly decelerating fan disk augmenting the airframe’s natural harmonics. The whole episode, with Skiles flying and Sullenberger operating the radios, from initial perception to left engine status recognition to sober realization of engine shutdown would take no more than five seconds. Tick-tock times five. That leaves 50 seconds unaccounted of cockpit scrambling and crew conversation.
Between the Botanical Gardens and Grand Concourse ASDI readings Cactus 1549 descended 1200’ over 1.73nm at 198kt average in 31.5 seconds, a glide rate of just over twice the normal autopilot ILS glide slope descent of -3 degrees. This aircraft was now a glider on its way down to sea level with nothing that the crew could do to reverse the descent.
Aircraft emergencies are radioed to ATC with ‘Pan-Pan-Pan’ or ‘Mayday-Mayday-Mayday’. Pan means the crew has encountered a midair problem or problems but the aircraft remains airworthy. Mayday is a non-airworthy aircraft going down whether in controlled flight or out of control. 1549’s left engine shutdown approaching the Bronx Zoo would be a Pan-Pan-Pan situation as the right engine continued to work and had to. But Pilots will most tend to declare 'Mayday', opting for the more dire term in the subsequent confusion even though, in hindsight only, not in any actual imminent danger. It is known that Sullenberger radioed Mayday at some point on or around the Botanical Garden 3200’ ASDI data hit to TRACON but inadvertently forgot to press the Push-to-Talk button and nobody besides Skiles and the cockpit boom microphones, and possibly a forward flight attendant, heard the call. This call was leaked after the fact by sources directly involved in the audio analysis and then promptly muzzled. Sullenberger’s Mayday, and many other unreleased comments, was recorded on the cockpit voice recorder via the boom mics, the same audio source used by the FAA and NTSB who edited out Sullenberger’s Mayday from the initial public release and all subsequent TRACON audio. TRACON never heard the Mayday and Sullenberger didn’t know that TRACON didn’t hear, thus TRACON’s nonchalant 270 turn instruction must’ve been received by Sullenberger with bewilderment.
The nonchalant TRACON instruction was broadcast at 3:27:36PM local time after Cactus 1549 had been in an unpowered descent out of 3200’ for at least 20 seconds.
There are two possible options to explain the double IFSD on an aircraft whose right engine continued to produce normal forward thrust for some time after the left packed it in and Sullenberger’s most atypical radio silence:
First, and highly unlikely but possible, the crew accidentally shutdown the good right engine in the ensuing tumult or, two, the CFM/Airbus electronic engine control system intervened and shut it down or, three, mechanical and/or electrical engine failure. A forward flight attendant reported a “burning electrical- or metallic-like odor.” (Aviation Week) As for Sullenberger’s silence, he did radio a Mayday and aircraft status, only it never broadcast in VHF from the aircraft because the button wasn’t pushed and the actual situation wasn’t a true mayday until 30 seconds after the botched Mayday call. After which either missed the PTT again while making a followup Mayday when TRACON didn't respond or was too irate or flabberghasted at the situation to bother. Completely inexplicable, since anathema to all similar recorded events. Only the full unedited cockpit boom mics audio release will tell.
Engine shutdowns are extremely confusing to pin down the real problem due to identical symptoms being indicative of completely different issues, especially tough after startled by a loud bang and jostled by a yaw. But it doesn’t explain or excuse Sullenberger’s exorbitant delay to alert TRACON in dumbfounding contradiction to ATP standard procedure.
Come Fly the PR’d Skies
Between circa 2002-2006 NASA spent $8.5 million to survey 24,000 U.S. civil and general aviation pilots by phone on the full slate of pilot safety concerns from bird strikes to runway incursions to near midair collisions to bad ATC. The results were so disturbing that NASA’s top bananas canceled the program and shelved the intended report. When the media caught wind and filed FOIA applications NASA finally released an indecipherable whitewash of raw data right on New Year’s Eve 2007, catching off guard and perplexing analysts trying to extrapolate its meanings. In time the analysts determined that the 24,000 pilots revealed that the frequency and severity of potentially catastrophic aviation incidents in U.S. airspace and airports is at least twice what the FAA reports, themselves initially surprised at the revelation while supportive, naturally, of NASA’s initial publication ban. If FAA numbers appear surprising, it’s not even half the story.
U.S. commercial aviation ownership to the FAA to the NTSB is a big shell game. Everything this collective group utters or prints is designed to keep American air travelers flocking to the airline check-in counters oblivious as sheep to the true state of U.S. commercial aviation. The NTSB is a fully independent agency that subcontracts with the U.S. government, answers to nobody and deflects blame by railroading easy scapegoats in high stakes disasters; the FAA does not actively intervene in airline operations to ensure airworthiness safety, unless kicked, endorses purely voluntary reporting of service difficulties, and in fact sought to eliminate detailed descriptions and serial numbers included in Service Difficulty Reports to the shocked dismay and vociferous protest by major U.S. carriers. Something akin to Wall Street-style self-regulation applied to U.S. commercial aviation. Not promising.
The Snap, Fumble and Interception
US Airways ‘America West’ AWE “Cactus” 1549 co-pilot Skiles operated the A320’s radios from the gate to just before line up on departure Runway 04. At this swap over, Sullenberger took over the radios and Skiles took over flying duties.
Skiles committed two oversights while parked at the La Guardia terminal. He contacted Ground Control at 20:08 UTC (3:08pm EST) to request taxi from stand 28 to the active forgetting to check in with Clearance Delivery as mandatory to receive approved IFR clearance. Ground started to issue initial taxi instruction while scanning 1549’s flight plan to realize that Skiles hadn’t been cleared to go anywhere. The controller stopped and asked Skiles if he’d spoken to Clearance. Skiles responded: “Ah, sorry, I forgot.” So Ground told him to contact the Clearance frequency. After contacting Clearance Skiles forgot a second mandatory procedure, read back confirmation that 1549 had consulted and understood the current active Automated Terminal Information System (ATIS) meteorological report (METAR). The METAR was PAPA, which Sullenberger had consulted and understood, and you can actually hear Sullenberger’s voice in the background telling Skiles “we have PAPA” at 11min57sec on the Clearance audio. Skiles neglected to consult the ATIS, forgot to mention this to Clearance and only reiterated to Clearance what Sullenberger had told him. Skiles, for a pilot about to take the controls out of La Guardia, had not even consulted the weather.
Highly irregular slipups for a pilot with 23 years at US Airways, as if just prior and unexpectantly paged into active flight duty and just arrived in the cockpit. It’s known that U.S. airlines push pilots and crews beyond practical and reasonable workloads to handle the crush of paying air travelers. Perhaps this played a factor in Skiles uncharacteristic oversights for an experienced ATP.
PAPA advised winds from 340 degrees at 13kt, visibility 10 statute miles, and broken ceiling at 3500’, more than adequate to see clear to Yonkers, well past the Bronx, without obstruction once airborne and any object in the initial climb to 5000’.
Excluding the eventual flock encounter, if did occur, Skiles committed two other flubs after twin engine shutdown. He neglected to engage the A320’s Ditch Switch that closes the air conditioning packs ram air inlets located on the mid-fuselage belly and other inlet points from water penetration (ultimately a minor issue since emergency exit doors were later opened that pooled in thousands of gallons of water causing chaos) and, second, since now working the radios or should’ve with Sullenberger assuming flying duties, advising TRACON below the radar floor of the aircraft’s status, intentions, direction, altitude and estimated splashdown point circa mid-Manhattan. In any event, maintaining constant contact with the radar unit. It is known that Skiles was desperately trying to restart the engines, but there comes a point where futility intercedes and the priorities become batten the hatches and don the lifejackets. It remains unclear if Cactus 1549’s A320 had Full Authority Digital Engine Control (FADEC) thus continuous active Auxiliary Power Unit (APU) running up to cruise flight level for quick engine restart capability or not. If no FADEC then the APU would have to be fired up, permitting zero chance of restart and engine spooling to sufficient N1 all from 3200’ in a -6 degree down glide.
It’s much easier to criticize pilot actions after the fact, not being ATP, or in that cockpit at the time and having zero association, than what these pilots endured and did. But these pilots are highly trained and paid to handle just such emergencies in A320 hydraulic simulators, marvels of technology, in which devious ‘Dracula’ technicians throw every conceivable disaster scenario at pilots. Emergency preparedness and continuous communication with ATC in real emergencies are inviolably critical, and Skiles never prepped the aircraft or even attempted ATC contact prior or after the A320 dropped below radar. Simulators are unable to replicate the true shocking extent of engine bang and shutdown, but do train ATP what to do in the aftermath.
Sullenberger also committed a slew of noteworthy oversights, even verbally acknowledged afterward that he’d rather maintain the fictional hero mantle than disappoint his hero worshippers. Two notables, he forgot to press the Press-to-Talk (PTT), HOT-1 recorded microphone as mentioned, when he called Mayday. TRACON never heard it. Second, when did press the button, issued a vague aircraft status by “lost thrust in both engines.” That can mean any percentage of N1 loss leaving a broad margin for interpretation. Despite that the TRACON controller did recognize the emergency before mangling proper procedure.
This was not a well planned and carried out leg to Charlotte, NC for the 1549 milk run. Nor was Cactus AWE2179, a CFM 56-5B powered Airbus 319, which never even got off the ground and had to return to the gate a few minutes after 1549 received clearance with an undetermined “maintenance ops problem.” A problem, in any case, that ruled out any notion of getting airborne until properly diagnosed and repaired.
As pilot-in-command, Sullenberger was responsible for every action that happened in that cockpit from initial boarding to embarking. Every checklist, control movement of the aircraft, radio transmissions, all exclusively dedicated to the safety of the aircraft and all onboard.
Sullenberger forgot PTT when called mayday, issued vague trouble status, and then let Skiles slam into an entire flock (if true), had no emergency diversion plans at the ready once airborne, and failed to activate or command Skiles to engage the ditch switch.
Sullenberger did three things right. Performed a perfect water landing, promptly declared “Evacuate,” and then made sure all onboard had safely evacuated, making several cabin aisle passes to be certain, and least he could do by this point.
Moving to the La Guardia Departure/Approach controller: the moment an aircraft in a controller’s airspace/responsibility is confirmed to be in trouble the frequency becomes a dedicated channel of emergency communication to the stricken aircraft. All other aircraft on the channel, no ifs, ands or buts, are handed off by self-explanatory order to the next controller in the designated ATC airspace sequence by rapid ATC coordination and with all departures halted. All current departures would switch to New York Center and all inbound approaches to La Guardia Tower with Departure in exclusive communication with Cactus 1549 transformed into a dedicated rescue operation in force.
The Departure controller didn’t cordon the channel and couldn’t even get the stricken Cactus callsign right, while did halt departures, repeatedly addressing or referring to 1549 as “Cactus fifteen *twenty* nine” like a stooge. An error that half asleep pilots make on return trips with new a callsign, still accustomed to the first callsign. Even Tower was puzzled. After finally correcting his error the controller continued to handle other departures and arrivals while 1549 was pulling out the paddles and oars. This is not the proper way to handle an emergency. In all probability the controller was just not prepared to handle the situation. Except they’re supposed to instantly assume the worst, if necessary force a detailed status from the affected crew and devote their entire attention and available resources to ensuring the best possible outcome for the stricken aircraft. While 1549 was making its most unprecedented commodore boat sail-by inspection of the USS Intrepid, La Guardia Departure/Approach continued to turn, climb and descend other aircraft as if nothing had happened.
1549 was cleared to Charlotte on the La Guardia Two departure with left turn to heading 360 on wheels off, initial climb to 5000’ and contact Departure on 124.400 when airborne. When Tower cleared 1549 for takeoff it meant that Tower was safely satisfied that no other aircraft or airborne object was on the same departure path or on intercept course. The Tower controller is one of several operators that supervise and manage all takeoffs, landings and aircraft movement on the active runways, always looking for the slightest abnormality and monitoring all departing aircraft for engine fire, etc, once airborne. So, not just a lone employee in a tower handling all tower duties, but several pairs of eyes roaming the sky and active runways in constant communication. None of the Tower staff, in bird central La Guardia, saw any birds on or in collision course proximity to Cactus 1549’s departure path.
The Radar Riddle
The NEXRAD Radar system in New York City, one branch of a near contiguous network of overlapping coverage across the continental USA, is so accurate it can measure wind speed and direction. It sees bugs. It’ll pick up geese, all right, and an A320 on collision intercept.
The NEXRAD emits an energy burst that reflects off geese and A320 on intercept course, scattering most of the energy but reflecting back enough dBZ (decibels of Z) to gauge biological or manmade, approximate size, analyzing and recording every possible flight perimeter 1300 times/second every second non-stop, why it’s called ‘real-time’ radar. It can measure bird wing beats, narrowing the identification to bird Family, i.e., waterfowl.
This primary bird radar system is backed up by ‘high-resolution’ mobile units located within the terminal. Both systems are equipped with warning alarms. The alarm will grab a radar operator’s undivided attention to any imminent bird strike with an aircraft and the whole reason why the incredible failsafe system was designed: a jetliner struck birds and crashed in the early 1970s without NEXRAD to see and avoid. Bear in mind, though, that La Guardia might not have and/or employ the mobile system. There is no mandatory regulation, thanks to the FAA, for cicil airports to have these systems. However, NEXRAD can detect raindrops, so detecting geese, and there were no raindrops that afternoon, is a piece of cake for NEXRAD. Whether or not anyone at the Westbury, New York TRACON was looking that afternoon is another matter. If they weren't, so much for their primary responsibility for the safe, orderly flow of departure, arrival and en route aircraft. Best yet, with or without 'real-time' bird radar, two pairs of diligently roving cockpit eyes beat out the best wildlife radar system everytime.
In clear skies from sea level to 3200’ over the East River and Bronx from 3:25pm onward on January 15, 2009, all the New York City NEXRAD would detect is winds, A320 and a big damn perfect formation of geese a couple of miles up the way backed up and verified on secondary mobile. The radar units didn’t see any birds and no alarm ever sounded to grab their attention. Every post-water landing claim that NY TRACON did in fact see bird returns at time of bird strike is deliberate utter deceit. This would presume that a state of the art detection system costing tens of millions and years to design and micro refine, would be handed to not just one negligent derelict but two entire multi-staffed bird units of complete negligent derelicts. Not a chance of this happening. Here's one modern day bird radar system: http://www.detect-inc.com/
The TRACON departure unit that 1549 contacted while climbing through 700’ didn’t detect any birds either. Once again the radar unit is multi-staffed with a controller, flight data processors, and full-time weather/wildlife medium range radar surveillance operators. The controller scans for aircraft and aircraft-to-terrain separation while other radar operators scan for weather and birds. None spotted any birds. Thus not a blip at the 2800’ left engine shutdown location over the Bronx.
There was no bird advisory issued to 1549 by Tower or TRACON. No pilot report from any preceding departure relayed by Tower or TRACON having just flown the same or similar route over the Bronx. No ensuing departure, in particular Eagle Flight (EGF) 4718, reported birds.
The flying V-formation of even a small skein of mature Canada Geese is unmistakable from miles away. If were true that the “windshield filled up with birds” according to Sullenberger and Skiles post-incident statements, then the flock was sizable. A small flock of nine to eleven geese flying wingtip-to-wingtip exceeds the wingspan and cross-section of a little Cessna 172 with near identical radar return. The geese will show up on radar in the shape of a delta wing, and being dark brown are even more noticeable from a flight deck than typically white-painted Cessnas in contrast to an azure sky. Just as airline transport pilots will do everything in their power to avoid colliding with a wayward Cessna in their path after takeoff, massive air traffic control negligence if were to occur, they’ll steer clear of any and all waterfowl they can avoid. The P-in-C has ultimate say of where the aircraft goes, assigned Clearance route or ATC instruction take a back seat, and by handing the flying duties to Skiles, Skiles had the authority to fly that aircraft in whichever direction, altitude and speed necessary to steer clear of any airborne object(s).
Only in the USA, the most propagandizing concentrated corporate media/PR system, can airline transport pilots be credited as “Hero” for smashing their aircraft with 155 onboard into an avoidable, unmistakable “perfect formation” (Skiles) of geese that only two people, Skiles and Sullenberger, purportedly saw. Most airlines would have stern words at bare minimum and on obvious grounds with any company pilot(s) that did this and the coinciding ATC lapses necessary to let it happen. Not US Airways, though.
The affair was milked as a major PR victory for U.S. commercial aviation. Hero pilots who saved 155 people.
Really? This must really refer to redemption, the least the crew could do, having smashed into a sizable perfect formation.
Neither La Guardia Tower by visual sweep or NY TRACON by radar picked up a flock of geese nor did any preceding crew or ensuing crew. Not even EGF4718 departing immediately after Cactus 1549 on the same route over the Bronx equipped now with the knowledge of 1549’s feathered ordeal, report spotting remnants of any splintered geese formation over the Bronx. As if the birds just vanished.
Where did these geese come from? Where did they go? Why didn’t Tower see them? Why didn’t radar? How does a co-pilot with 23 years experience and full aircraft authority fly into an entire flock that he knew were there? How does a P-in-C let this happen?
When geese smash into a jetliner’s windshield at 150kt-180kt closure, as Sullenberger and Skiles claimed happened, they explode on impact leaving a large windswept blood smear that doesn’t get wiped clear by 200kt winds. There was no blood smear on Cactus 1549’s windshield when recovered from the Hudson River. No Hudson water shot over the windshield on landing and if did would’ve partially or totally plunged the aircraft’s nose and cockpit beneath the surface. The underside of the front nose fuselage section acted like a boat hull on touchdown keeping the cabin and windshield on the dry side at all times, thanks to Sullenberger’s controlled landing. The nose on 1549 was blemish-free after coming to a floating halt. All nose damage visible on subsequent photos was caused by police boats and/or ferry boats, the true heroes that afternoon, from either/or banging their vessel into the nose area to stabilize the aircraft so all onboard could be evacuated onto ferries. All leading edge and wingtip damage on the left wing was caused during the understandibly rough and tumble barging process to shore by tugboats and other vessels.
Canada Geese do not just materialize at 2800’ over the Bronx in front of an A320’s super strong goose-proof windshield. It takes many minutes, a great deal longer for these birds to reach this height and cover distance while up there than an A320 climbing at 1800’-2000’/minute and 151-174kt forward speed. From sea level to 2800’ on January 15, 2009, the La Guardia to Bronx skies were clear. Not one cloud wisp to obscure Skiles’ constantly roaming forward, lateral and vertical visibility.
In clear skies, like the afternoon of January 15, 2009, a sizable “perfect formation” of geese, as co-pilot Skiles told the New Scotsman and many other media, would be unmistakable no matter which direction of flight, speed or intercept trajectory to vigilant probing eyes on the flight deck, medium range radar return, La Guardia Tower binoculars, preceding aircraft and scattered remnants easily identifiable by EGF4718 following about two minutes behind.
Skiles, flying the aircraft from the right seat at the time, not only ought to have spotted this perfect formation from safely afar, but in his own words did, and right up until slamming center hole.
There’s an enigma here, several, in fact.
Why didn’t Stiles make any effort to avoid birds that he knew, in his own admission, were there? These birds, if really present, didn’t fly into that Airbus, the Airbus flew into them with Skiles at the sidestick and concentration focused outside the windshield while Sullenberger worked the radios, scanned the glass panels and monitored Skiles.
Why didn’t P-in-C, Sullenberger, make any effort to intervene and circumvent Skiles’ most non-airworthy decision to bullseye an entire flock?
How do legendary super vigilant geese fail to detect and/or make no subsequent effort to scatter in collective defence from a huge, fast approaching menacing predator bearing down on them in perfect visibility?
The CFM 56-5B engines are spaced under the wings just under 36 ½’ on center apart. Enough distance to pack 7-to-10 mature Canada Geese flying head-on in level flight at the engines or rear-ended in wingtip-to-wingtip formation, and even more geese in a T-bone configuration. If the windshield, according to Skiles, “filled up with birds,” a substantial portion of the flock must’ve been nearly 6’ above the wings. How come no geese hit the windshield, radome or wing leading edges? How does a windshield full of geese present one instant, which purportedly caused Sullenberger to instinctively duck, disappear the next?
I might have the answer to all the above:
CFM 56-5B High Pressure Compressor(HPC) Surge and Stall by GE Aviation Design Flaw
The CFM 56-5B has a sordid operational record confirmed by numerous A320 worldwide operator complaints in 2007 about HPC surges and stalls with ineffectual software update 5QB to remedy the irreparable problem.
The CFM 56-5B HPC unit, designed and built by GE Aviation, deteriorates after an unknown but at some definite point number of operational flying hours. There is no known fix beside new engine replacement of at least one engine unit should Exhaust Gas Temperature exceed 75 degrees Celsius during ground test before each departure, as mandated by CFM/GEA/Airbus and EASA “Emergency” maintenance directive.
Two days prior over Newark, the exact 1549 aircraft and engines, also callsign Cactus 1549, since the same milk run, suffered a compressor stall in the *right* engine while climbing to cruise. Passenger, John Hodock, on this flight, told CNN by e-mail: "About 20 minutes after take-off, the plane had a series of compressor stalls on the right engine.” (thanks to a Facebook page for this). The recoverable surge/stall occurred near 28,000’. The crew restarted the engine and continued on to an uneventful landing at its intended destination after originally informing passengers that it would have to return to La Guardia.
The left engine went boom on Cactus 1549 at 2800’. This makes both CFM 56-5Bs encountering total loss of thrust within 48 hours. No wonder the engines were hauled away to GE Aviation’s headquarters in Ohio for teardown. America West (US Airways) replaced a temperature probe on the Newark right engine.
Uh-Oh! Better Get Maaco!
The left photo shows what a bird strike deals out to a little private jet. The force released by a bird hitting an aircraft is ½ bird mass times velocity squared. A haymaker that leaves a crater on impact in the aluminum leading surfaces or edges roughly the size of the bird. Not Cactus 1549, though. As readily seen in the right photo, expand and zoom in your photo viewer whichever way, it is spotless. Not a tell-tale dent or blood smear anywhere indicative of goose strike after purportedly slamming into an entire flock. The photo doesn't show the port side, but if there were dents and blood smear out of view then the NTSB would've mentioned so with photo evidence in support.
There have been about four recorded incidents in jet age civil aviation history of airliners on departure or approach (not takeoff or short final or en route) colliding with an entire flock of birds and occurred because of poor or limited visibility. A Polar Air Cargo 747, flying out of a cloudbank, hit a flock of snow geese on approach to JFK at 7500’ in December, 1995. Neither had a chance to see and avoid. The 747 lost one engine and the leading surfaces and edges were cratered with goose hits that the pilot afterward said sounded like “sandbags.” None of these aircraft, while took a beating, crashed. In 1996, a Belgian military C-130 Hercules collided with a flock on short final and lost three engines. The crew mistakenly aborted the landing and attempted a go-around with the one remaining engine, stalled, crashed, and 34 of the 37 aboard died, including the whole crew.
There has never been an entire flock collision in the departure climb out stage in clear skies by a civil jet airliner. Cactus 1549, as the U.S. corporate media will have it believed, is the first.
Remarkable coincidence for a right engine that surged and stalled with repeated loud popping sounds over Newark 48 hours prior loud enough to jostle slumbering passengers awake and after which USAir only replaced a temperature probe.
A HPC surges when air forcing its way into the business section, the turbojet core, is blocked by a wall of existing air. The core can’t handle the air volume that simultaneously explodes out the back exhaust and front intake. A turbofan is a turbojet with a turbine-driven fan disk that intakes and throws, on the 56-5B, 5.5 more units of air into the bypass air flow region for every 1 unit in the core. Surplus core air collides with existing air and half is forcibly ejected out the direction it came. Forced out at high speed the wrong way out through high and low compressor stages and fan disk intake causing a series of very loud booms per cycle that sound like explosions to those onboard or at a distance. These explosions of supercharged air are occasionally so forceful that the ejected air distorts and destroys blades that trigger a fast domino effect that destroys other blades, progressively destroying the engine. Both recoverable and unrecoverable compressor surges stall and shutdown the engine.
When no damage occurs the engine can be restarted and thereafter operated, as happened 48 hours before over Newark, at reduced N1 without further issue.
There is no imminent need for the crew to do anything other than fly the aircraft and report the incident as soon as possible to ATC after a jarring boom and engine shutdown. It is to the contrary expressly advised to slowly and methodically 100% identify and confirm the actual problem by abnormal event checklist diagnosis and crew resource management. The aircraft’s other remaining engine is more than adequate to remain airborne and, in fact, easily takeoff and climb.
But not 48 hours later over the Bronx. Where there’s one unaddressed HPC stall, there’s always another just around the corner. Slung under the other wing.
The A320 is backup system reinforced to redundancy. It has more back up sensors for every measurable flight and engine perimeter and flight management systems than will ever need. Like a sky diver with a main chute and four backup chutes. The odds of all five chutes failing are astronomical. The CFM 56-5B, however, only has one HPC per engine. There is no backup should it deteriorate in midair. When this HPC deteriorates, that’s it for the engine. The stalled engine, if restart is not possible, becomes a passenger, carried through the air to hopeful uneventful landing by the remaining good engine. Should this remaining engine stall, that’s really it. The aircraft is now a glider, like Cactus 1549.
The same right engine, with new temperature probe, that quit for unknown reason(s) over the Bronx on January 15, 2009, was the same engine that compressor surged and stalled over Newark Jan.13. Same HPC with ineffectual 5BQ software to close the variable stators by 2 additional degrees at low power setting.
An A320 rolls down the runway at takeoff after a gingerly gradual power setting throttled up to about 95%. The crew holds this power setting once airborne until established on a safe climb regimen and then gingerly throttles back, now having attained safe forward momentum, to about 90% and holds this setting all the way to cruise flight level to conserve fuel. On throttle back from 95% to 90% the N1 briefly cuts back to idle, dropping to below low power setting. Herein a mystery occurs inside the CFM 56-5B that stresses and deteriorates the HPC after indeterminate hours of active operation.
A turbofan has to micromanage the air that flows into the core achieved by state of the art computers performing mindboggling fast calculations and adjustments. Not enough air and thrust drops off; too much and it collides with existing air. The CFM 56-5B can’t manage this core flow under certain situations and surges with no known fix other than toss the deteriorated engine and bolt on a new one.
USAir did not replace the engine that stalled over Newark prompting some passengers, literally, to discuss their last will and testament in withdrawn sarcasm and text message next of kin.
Cactus 1549’s left engine emitted a single very loud bang at 2800’, heard by all onboard, and then shutdown. One bang and one only followed by a flameout witnessed by some passengers on the left side. Birds ingested into turbofans do not cause a one-time loud bang. When a bird damages or breaks a blade it causes a series of pops with flame burst each time as the engine is in the midst of progressively disintegrating until shutdown by the pilots. Nothing flew into Cactus 1549’s right engine. There was no loud bang emanating from the right engine or any pops with flame burst. It just shutdown. That’s not a bird strike. It’s a midair engine shutdown by either computer management sensing serious problems inside the unit after the left engine surged and stalled, crew error shutting down the wrong engine, or the engine just packed it in by mechanical or electronic cause.
A flight attendant reported burning metallic or electrical odor. Which engine or other source did it come from? The turbofan bleed air system draws air into the cabin, cargo hold and wings to anti-ice from the low and high pressure compressor stages before the fuel stage. The bleed air is so hot, heated by the compression of ambient air to 40psi, that it must be cooled by dilution with ambient air drawn from the ram air inlets, the ones the 1549 crew forgot to close.
In a compressor surge by blade deterioration, bird strike or other, the exploding air, typically ignited, is blasted past the bleed air inlets at explosive speed with a miniscule amount drawn in the bleed air system then heavily diluted by the packs with ambient air before piped into the cabin. In mere milliseconds after the forward traveling flash burst is over and air is rushing through the engine and out the exhaust at whichever speed it gets by the fan disk or whatever of its blades remain. All raw kerosene jet fuel dumping in the now useless engine is blown out the exhaust, usually ignited forming a flame trail, but nowhere near the bleed air inlets even at severely constrained velocity. Thus not even burnt fuel vapour besides a negligible amount can realistically infiltrate the cabin. Only engine lubricating oil and other liquids via faulty seal(s) can infiltrate from the engine, but at such miniscule parts per million, since so heavily diluted, as to be unnoticeable by the human olfactory system, and why those onboard develop headaches, sore throat, dry itchy skin, and so on, after long flights without ever knowing why. Metallic or electrical odor from within the engines can only emanate from a source upwind of the bleed inlets or from inside the packs or else drawn in through the ram inlets. The ram inlets will draw in the toxic plumes of ground-based electrical fires, and air pollution, though so improbable as to be next to impossible that this is what occurred. The reported odor was so pungent as to imply cabin fire. One flight attendant called for a fire extinguisher. It’ll be interesting to learn the source of this odor and if and how connected to the loud boom.
However civil-minded and composed passengers normally are, once a captain declares “brace for impact” a whole new set of rules begin to apply. Once thousands of gallons of frigid Hudson water rush in, submerging passengers from the ankles to their chest, especially toward the back of coach, it’s a free for all melee to the closest exit. Terrified passengers clawed over the seats, shouting, wanting nothing other than running like hell toward and out the closest door. Only two forward and one aft attendant to instruct and regulate the evacuation of 150 passengers would be an impossible onus. They tried as best as possible. Once outside standing on the wings, feet and legs rapidly numbing, strength and balance waning, with many already drenched while inside, the sight of approaching Hudson ferries must’ve been sheer elation. In the wind down once aboard these rescue boats to reaching shore and taken to 42nd Street, reality began to settle in with pointed, awkward questions forming. How did this happen?
One fact is certain. If geese did hit that plane, it would be the least of the plane's inherent problems.
“Other passengers on Flight 1549[…] had heard what sounded like an explosion. Elizabeth McHugh, a project manager for a company that installs information systems in hospitals, called it ‘a big bang’. Karin Hill, a college student on her way to Denver, called it ‘a loud thud’.” (NYT, Jan.16, 2009, “US Airways: A Passenger’s Account”)
Engine damaging bird ingestions, as viewable on many a YouTube video, cause a ‘POP!…P-POP!…POP!…POP!...’ effect with accompanying flame burst each time, similar to repeated strikes of a sledgehammer on a steel I-Beam. A completely different effect to a compressor surge where highly compressed air explodes out the intake and exhaust in a one-time extremely loud boom.
A one-time loud engine bang (or thud depending on proximity and discretionary interpretation of audible sounds) heard in the cockpit followed by shooting flame, rapid yaw and vibration is so startling that it can shock experienced pilot(s) into a string of errors. The most prominent of these: failing to continue flying the aircraft, misdiagnosing the real problem and inadvertently shutting down, especially unproductive on a twin engine aircraft, the remaining good engine. It is doubtful that Cactus 1549’s crew committed any of these errors and the point of iterating such is that these encounters are terrifying to any airline transport pilot.
It is known that Cactus 1549, as recorded by its Aircraft Situation Display to Industry (ASDI) data stream (FlightAware.com), committed an unapproved, uncommanded 15 degree left turn course deviation off its assigned 360 degree departure route just south of the Bronx Zoo. The veer strongly suggests that the severe left engine event occurred right here at circa 2800’ at 174kt forward speed that yawed the aircraft off course without detected or acted upon by the Departure controller. A report on Wikipedia alleges that the shutdown occurred at 3200', but this interpretation doesn't account for the preceding course deviation or the total lack of yaw at this presumed 3200' shutdown point. In-Flight Shutdown (IFSD) induces unavoidable yaw as the engine fan disk rapidly decelerates and takes on the attributes of an unconventional parachute while the opposite engine continues to spool at N1 climb setting rpm, inducing an abrupt doubly powerful yaw motion as the dud left engine on Cactus 1549 acted like a brake while the good right engine pulled the right wing forward, forcing the left wing backward, turning the aircraft to port.
After regaining control co-pilot, Jeff Skiles, flying the aircraft, held this 345 heading for the next 3nm. After this veer the aircraft accelerated to 194kt while climbed an additional 400’, likely even higher. The laws of physics absolutely forbid unpowered aircraft to accelerate in a climb, therefore, the right engine must’ve been producing normal forward thrust after the left IFSD at 2800’ before it too eventually shutdown for unknown reason(s). The FAA and NTSB have not released the Flight Data Recorder parameters, rendering all explanation as speculation based on known ASDI, cockpit/TRACON audio tapes and personnel/passenger statements.
Cactus 1549 likely climbed a little beyond 3200’ as the ASDI continued to display a positive climb regimen at 40*51”36’N 73*52”48’W over New York Botanical Garden just east of Southern Blvd, mere instants before 1549 commenced an unpowered ‘deadstick’ descent. A double in-flight engine shutdown would not prevent a brief continued climb but would void any airspeed increase for being physically impossible from no energy supply to produce power to produce acceleration.
From loud bang and shutdown approaching the Bronx Zoo to the Botanical Gardens ASDI update Cactus 1549 traveled 1.85nm in 36.2 seconds at an average speed of 184kt. The right engine continued to work for the better part of this 36.2 seconds. Calling into question a flight attendant’s statement that all engine noise ceased after the initial boom and the cabin fell totally silent “like being in a library.” (Aviation Week “Update-Flight 1549 Inside the Cockpit, Inside the Cabin.”)
18-19 seconds and 1.1nm later TRACON, unaware of the A320’s situation, issued a standard left turn to heading 270* instruction to Cactus 1549 to route the aircraft north of Manhattan and eventually on course to BIGGY over New Jersey. Pilot-in-Command Chesley Sullenberger immediately and verbatim responded: “Ah, this is, uh, Cactus fifteen forty-nine, hit birds, we [have] lost thrust in both engines. We’re turning back towards La Guardia.” TRACON acknowledged Sullenberger and issued a left turn to 220* at 3:27:42PM. Either Sullenberger or co-pilot Skiles (originally flying), since unconfirmed which now, commenced an immediate sharp left bank to 220* beginning over the intersection of Mosholu Parkway and Grand Concourse. All told 55 seconds elapsed from the left engine shutdown to TRACON first learning of 1549’s situation.
Pilots do not dawdle for the better part of 55 seconds before choosing to alert a radar unit of a major midair emergency. What happened in these 55 seconds?
Reasonably inferring from the ASDIs and audio tapes, at circa 2800’, without warning, the left engine emitted a loud boom, the engine shutdown, aircraft abruptly yawed left, and the airframe shuddered, all normal consequences, startling the pilots and all onboard.
But not a sound or flame emanated from the right engine. Birds ingested through the fan disk that destroy the engine cannot damage fan blades, variable stators and static turbines without unmistakable audible and visual indication. The ingestion has to induce a series of abnormal loud popping sounds with accompanying flame burst and/or ignited raw kerosene flaming out the exhaust. Therefore, no geese or any birds could’ve been ingested into Cactus 1549’s right engine or all onboard would’ve heard the unmistakable consequence and most of the right side cabin passengers would’ve seen the flames shrouding destroyed blades forcibly ejected in bits and pieces.
The left engine boom would stun Sullenberger and Skiles, eliciting verbal or silently contemplated ‘What the hell was THAT!’ reaction. The Master Warning siren would blare into action. The twin glass cockpit Engine Indicators/Crew Alert System (EICAS) and Electronic Centralized Aircraft Monitor (ECAM) would broadcast real-time engine parameters and trouble descriptions. N1 and N2 would quickly plummet, with possible, but not necessarily, Exhaust Gas Temperature increase and/or engine fire warning. The startling bang, sounding like a bomb exploding and most pronounced at low altitudes such as 2800’, would draw immediate pilot focus to the EICAS and ACAR while the aircraft yawed, partially banked and shuddered from the natural harmonics of the rapidly decelerating fan disk augmenting the airframe’s natural harmonics. The whole episode, with Skiles flying and Sullenberger operating the radios, from initial perception to left engine status recognition to sober realization of engine shutdown would take no more than five seconds. Tick-tock times five. That leaves 50 seconds unaccounted of cockpit scrambling and crew conversation.
Between the Botanical Gardens and Grand Concourse ASDI readings Cactus 1549 descended 1200’ over 1.73nm at 198kt average in 31.5 seconds, a glide rate of just over twice the normal autopilot ILS glide slope descent of -3 degrees. This aircraft was now a glider on its way down to sea level with nothing that the crew could do to reverse the descent.
Aircraft emergencies are radioed to ATC with ‘Pan-Pan-Pan’ or ‘Mayday-Mayday-Mayday’. Pan means the crew has encountered a midair problem or problems but the aircraft remains airworthy. Mayday is a non-airworthy aircraft going down whether in controlled flight or out of control. 1549’s left engine shutdown approaching the Bronx Zoo would be a Pan-Pan-Pan situation as the right engine continued to work and had to. But Pilots will most tend to declare 'Mayday', opting for the more dire term in the subsequent confusion even though, in hindsight only, not in any actual imminent danger. It is known that Sullenberger radioed Mayday at some point on or around the Botanical Garden 3200’ ASDI data hit to TRACON but inadvertently forgot to press the Push-to-Talk button and nobody besides Skiles and the cockpit boom microphones, and possibly a forward flight attendant, heard the call. This call was leaked after the fact by sources directly involved in the audio analysis and then promptly muzzled. Sullenberger’s Mayday, and many other unreleased comments, was recorded on the cockpit voice recorder via the boom mics, the same audio source used by the FAA and NTSB who edited out Sullenberger’s Mayday from the initial public release and all subsequent TRACON audio. TRACON never heard the Mayday and Sullenberger didn’t know that TRACON didn’t hear, thus TRACON’s nonchalant 270 turn instruction must’ve been received by Sullenberger with bewilderment.
The nonchalant TRACON instruction was broadcast at 3:27:36PM local time after Cactus 1549 had been in an unpowered descent out of 3200’ for at least 20 seconds.
There are two possible options to explain the double IFSD on an aircraft whose right engine continued to produce normal forward thrust for some time after the left packed it in and Sullenberger’s most atypical radio silence:
First, and highly unlikely but possible, the crew accidentally shutdown the good right engine in the ensuing tumult or, two, the CFM/Airbus electronic engine control system intervened and shut it down or, three, mechanical and/or electrical engine failure. A forward flight attendant reported a “burning electrical- or metallic-like odor.” (Aviation Week) As for Sullenberger’s silence, he did radio a Mayday and aircraft status, only it never broadcast in VHF from the aircraft because the button wasn’t pushed and the actual situation wasn’t a true mayday until 30 seconds after the botched Mayday call. After which either missed the PTT again while making a followup Mayday when TRACON didn't respond or was too irate or flabberghasted at the situation to bother. Completely inexplicable, since anathema to all similar recorded events. Only the full unedited cockpit boom mics audio release will tell.
Engine shutdowns are extremely confusing to pin down the real problem due to identical symptoms being indicative of completely different issues, especially tough after startled by a loud bang and jostled by a yaw. But it doesn’t explain or excuse Sullenberger’s exorbitant delay to alert TRACON in dumbfounding contradiction to ATP standard procedure.
Come Fly the PR’d Skies
Between circa 2002-2006 NASA spent $8.5 million to survey 24,000 U.S. civil and general aviation pilots by phone on the full slate of pilot safety concerns from bird strikes to runway incursions to near midair collisions to bad ATC. The results were so disturbing that NASA’s top bananas canceled the program and shelved the intended report. When the media caught wind and filed FOIA applications NASA finally released an indecipherable whitewash of raw data right on New Year’s Eve 2007, catching off guard and perplexing analysts trying to extrapolate its meanings. In time the analysts determined that the 24,000 pilots revealed that the frequency and severity of potentially catastrophic aviation incidents in U.S. airspace and airports is at least twice what the FAA reports, themselves initially surprised at the revelation while supportive, naturally, of NASA’s initial publication ban. If FAA numbers appear surprising, it’s not even half the story.
U.S. commercial aviation ownership to the FAA to the NTSB is a big shell game. Everything this collective group utters or prints is designed to keep American air travelers flocking to the airline check-in counters oblivious as sheep to the true state of U.S. commercial aviation. The NTSB is a fully independent agency that subcontracts with the U.S. government, answers to nobody and deflects blame by railroading easy scapegoats in high stakes disasters; the FAA does not actively intervene in airline operations to ensure airworthiness safety, unless kicked, endorses purely voluntary reporting of service difficulties, and in fact sought to eliminate detailed descriptions and serial numbers included in Service Difficulty Reports to the shocked dismay and vociferous protest by major U.S. carriers. Something akin to Wall Street-style self-regulation applied to U.S. commercial aviation. Not promising.
The Snap, Fumble and Interception
US Airways ‘America West’ AWE “Cactus” 1549 co-pilot Skiles operated the A320’s radios from the gate to just before line up on departure Runway 04. At this swap over, Sullenberger took over the radios and Skiles took over flying duties.
Skiles committed two oversights while parked at the La Guardia terminal. He contacted Ground Control at 20:08 UTC (3:08pm EST) to request taxi from stand 28 to the active forgetting to check in with Clearance Delivery as mandatory to receive approved IFR clearance. Ground started to issue initial taxi instruction while scanning 1549’s flight plan to realize that Skiles hadn’t been cleared to go anywhere. The controller stopped and asked Skiles if he’d spoken to Clearance. Skiles responded: “Ah, sorry, I forgot.” So Ground told him to contact the Clearance frequency. After contacting Clearance Skiles forgot a second mandatory procedure, read back confirmation that 1549 had consulted and understood the current active Automated Terminal Information System (ATIS) meteorological report (METAR). The METAR was PAPA, which Sullenberger had consulted and understood, and you can actually hear Sullenberger’s voice in the background telling Skiles “we have PAPA” at 11min57sec on the Clearance audio. Skiles neglected to consult the ATIS, forgot to mention this to Clearance and only reiterated to Clearance what Sullenberger had told him. Skiles, for a pilot about to take the controls out of La Guardia, had not even consulted the weather.
Highly irregular slipups for a pilot with 23 years at US Airways, as if just prior and unexpectantly paged into active flight duty and just arrived in the cockpit. It’s known that U.S. airlines push pilots and crews beyond practical and reasonable workloads to handle the crush of paying air travelers. Perhaps this played a factor in Skiles uncharacteristic oversights for an experienced ATP.
PAPA advised winds from 340 degrees at 13kt, visibility 10 statute miles, and broken ceiling at 3500’, more than adequate to see clear to Yonkers, well past the Bronx, without obstruction once airborne and any object in the initial climb to 5000’.
Excluding the eventual flock encounter, if did occur, Skiles committed two other flubs after twin engine shutdown. He neglected to engage the A320’s Ditch Switch that closes the air conditioning packs ram air inlets located on the mid-fuselage belly and other inlet points from water penetration (ultimately a minor issue since emergency exit doors were later opened that pooled in thousands of gallons of water causing chaos) and, second, since now working the radios or should’ve with Sullenberger assuming flying duties, advising TRACON below the radar floor of the aircraft’s status, intentions, direction, altitude and estimated splashdown point circa mid-Manhattan. In any event, maintaining constant contact with the radar unit. It is known that Skiles was desperately trying to restart the engines, but there comes a point where futility intercedes and the priorities become batten the hatches and don the lifejackets. It remains unclear if Cactus 1549’s A320 had Full Authority Digital Engine Control (FADEC) thus continuous active Auxiliary Power Unit (APU) running up to cruise flight level for quick engine restart capability or not. If no FADEC then the APU would have to be fired up, permitting zero chance of restart and engine spooling to sufficient N1 all from 3200’ in a -6 degree down glide.
It’s much easier to criticize pilot actions after the fact, not being ATP, or in that cockpit at the time and having zero association, than what these pilots endured and did. But these pilots are highly trained and paid to handle just such emergencies in A320 hydraulic simulators, marvels of technology, in which devious ‘Dracula’ technicians throw every conceivable disaster scenario at pilots. Emergency preparedness and continuous communication with ATC in real emergencies are inviolably critical, and Skiles never prepped the aircraft or even attempted ATC contact prior or after the A320 dropped below radar. Simulators are unable to replicate the true shocking extent of engine bang and shutdown, but do train ATP what to do in the aftermath.
Sullenberger also committed a slew of noteworthy oversights, even verbally acknowledged afterward that he’d rather maintain the fictional hero mantle than disappoint his hero worshippers. Two notables, he forgot to press the Press-to-Talk (PTT), HOT-1 recorded microphone as mentioned, when he called Mayday. TRACON never heard it. Second, when did press the button, issued a vague aircraft status by “lost thrust in both engines.” That can mean any percentage of N1 loss leaving a broad margin for interpretation. Despite that the TRACON controller did recognize the emergency before mangling proper procedure.
This was not a well planned and carried out leg to Charlotte, NC for the 1549 milk run. Nor was Cactus AWE2179, a CFM 56-5B powered Airbus 319, which never even got off the ground and had to return to the gate a few minutes after 1549 received clearance with an undetermined “maintenance ops problem.” A problem, in any case, that ruled out any notion of getting airborne until properly diagnosed and repaired.
As pilot-in-command, Sullenberger was responsible for every action that happened in that cockpit from initial boarding to embarking. Every checklist, control movement of the aircraft, radio transmissions, all exclusively dedicated to the safety of the aircraft and all onboard.
Sullenberger forgot PTT when called mayday, issued vague trouble status, and then let Skiles slam into an entire flock (if true), had no emergency diversion plans at the ready once airborne, and failed to activate or command Skiles to engage the ditch switch.
Sullenberger did three things right. Performed a perfect water landing, promptly declared “Evacuate,” and then made sure all onboard had safely evacuated, making several cabin aisle passes to be certain, and least he could do by this point.
Moving to the La Guardia Departure/Approach controller: the moment an aircraft in a controller’s airspace/responsibility is confirmed to be in trouble the frequency becomes a dedicated channel of emergency communication to the stricken aircraft. All other aircraft on the channel, no ifs, ands or buts, are handed off by self-explanatory order to the next controller in the designated ATC airspace sequence by rapid ATC coordination and with all departures halted. All current departures would switch to New York Center and all inbound approaches to La Guardia Tower with Departure in exclusive communication with Cactus 1549 transformed into a dedicated rescue operation in force.
The Departure controller didn’t cordon the channel and couldn’t even get the stricken Cactus callsign right, while did halt departures, repeatedly addressing or referring to 1549 as “Cactus fifteen *twenty* nine” like a stooge. An error that half asleep pilots make on return trips with new a callsign, still accustomed to the first callsign. Even Tower was puzzled. After finally correcting his error the controller continued to handle other departures and arrivals while 1549 was pulling out the paddles and oars. This is not the proper way to handle an emergency. In all probability the controller was just not prepared to handle the situation. Except they’re supposed to instantly assume the worst, if necessary force a detailed status from the affected crew and devote their entire attention and available resources to ensuring the best possible outcome for the stricken aircraft. While 1549 was making its most unprecedented commodore boat sail-by inspection of the USS Intrepid, La Guardia Departure/Approach continued to turn, climb and descend other aircraft as if nothing had happened.
1549 was cleared to Charlotte on the La Guardia Two departure with left turn to heading 360 on wheels off, initial climb to 5000’ and contact Departure on 124.400 when airborne. When Tower cleared 1549 for takeoff it meant that Tower was safely satisfied that no other aircraft or airborne object was on the same departure path or on intercept course. The Tower controller is one of several operators that supervise and manage all takeoffs, landings and aircraft movement on the active runways, always looking for the slightest abnormality and monitoring all departing aircraft for engine fire, etc, once airborne. So, not just a lone employee in a tower handling all tower duties, but several pairs of eyes roaming the sky and active runways in constant communication. None of the Tower staff, in bird central La Guardia, saw any birds on or in collision course proximity to Cactus 1549’s departure path.
The Radar Riddle
The NEXRAD Radar system in New York City, one branch of a near contiguous network of overlapping coverage across the continental USA, is so accurate it can measure wind speed and direction. It sees bugs. It’ll pick up geese, all right, and an A320 on collision intercept.
The NEXRAD emits an energy burst that reflects off geese and A320 on intercept course, scattering most of the energy but reflecting back enough dBZ (decibels of Z) to gauge biological or manmade, approximate size, analyzing and recording every possible flight perimeter 1300 times/second every second non-stop, why it’s called ‘real-time’ radar. It can measure bird wing beats, narrowing the identification to bird Family, i.e., waterfowl.
This primary bird radar system is backed up by ‘high-resolution’ mobile units located within the terminal. Both systems are equipped with warning alarms. The alarm will grab a radar operator’s undivided attention to any imminent bird strike with an aircraft and the whole reason why the incredible failsafe system was designed: a jetliner struck birds and crashed in the early 1970s without NEXRAD to see and avoid. Bear in mind, though, that La Guardia might not have and/or employ the mobile system. There is no mandatory regulation, thanks to the FAA, for cicil airports to have these systems. However, NEXRAD can detect raindrops, so detecting geese, and there were no raindrops that afternoon, is a piece of cake for NEXRAD. Whether or not anyone at the Westbury, New York TRACON was looking that afternoon is another matter. If they weren't, so much for their primary responsibility for the safe, orderly flow of departure, arrival and en route aircraft. Best yet, with or without 'real-time' bird radar, two pairs of diligently roving cockpit eyes beat out the best wildlife radar system everytime.
In clear skies from sea level to 3200’ over the East River and Bronx from 3:25pm onward on January 15, 2009, all the New York City NEXRAD would detect is winds, A320 and a big damn perfect formation of geese a couple of miles up the way backed up and verified on secondary mobile. The radar units didn’t see any birds and no alarm ever sounded to grab their attention. Every post-water landing claim that NY TRACON did in fact see bird returns at time of bird strike is deliberate utter deceit. This would presume that a state of the art detection system costing tens of millions and years to design and micro refine, would be handed to not just one negligent derelict but two entire multi-staffed bird units of complete negligent derelicts. Not a chance of this happening. Here's one modern day bird radar system: http://www.detect-inc.com/
The TRACON departure unit that 1549 contacted while climbing through 700’ didn’t detect any birds either. Once again the radar unit is multi-staffed with a controller, flight data processors, and full-time weather/wildlife medium range radar surveillance operators. The controller scans for aircraft and aircraft-to-terrain separation while other radar operators scan for weather and birds. None spotted any birds. Thus not a blip at the 2800’ left engine shutdown location over the Bronx.
There was no bird advisory issued to 1549 by Tower or TRACON. No pilot report from any preceding departure relayed by Tower or TRACON having just flown the same or similar route over the Bronx. No ensuing departure, in particular Eagle Flight (EGF) 4718, reported birds.
The flying V-formation of even a small skein of mature Canada Geese is unmistakable from miles away. If were true that the “windshield filled up with birds” according to Sullenberger and Skiles post-incident statements, then the flock was sizable. A small flock of nine to eleven geese flying wingtip-to-wingtip exceeds the wingspan and cross-section of a little Cessna 172 with near identical radar return. The geese will show up on radar in the shape of a delta wing, and being dark brown are even more noticeable from a flight deck than typically white-painted Cessnas in contrast to an azure sky. Just as airline transport pilots will do everything in their power to avoid colliding with a wayward Cessna in their path after takeoff, massive air traffic control negligence if were to occur, they’ll steer clear of any and all waterfowl they can avoid. The P-in-C has ultimate say of where the aircraft goes, assigned Clearance route or ATC instruction take a back seat, and by handing the flying duties to Skiles, Skiles had the authority to fly that aircraft in whichever direction, altitude and speed necessary to steer clear of any airborne object(s).
Only in the USA, the most propagandizing concentrated corporate media/PR system, can airline transport pilots be credited as “Hero” for smashing their aircraft with 155 onboard into an avoidable, unmistakable “perfect formation” (Skiles) of geese that only two people, Skiles and Sullenberger, purportedly saw. Most airlines would have stern words at bare minimum and on obvious grounds with any company pilot(s) that did this and the coinciding ATC lapses necessary to let it happen. Not US Airways, though.
The affair was milked as a major PR victory for U.S. commercial aviation. Hero pilots who saved 155 people.
Really? This must really refer to redemption, the least the crew could do, having smashed into a sizable perfect formation.
Neither La Guardia Tower by visual sweep or NY TRACON by radar picked up a flock of geese nor did any preceding crew or ensuing crew. Not even EGF4718 departing immediately after Cactus 1549 on the same route over the Bronx equipped now with the knowledge of 1549’s feathered ordeal, report spotting remnants of any splintered geese formation over the Bronx. As if the birds just vanished.
Where did these geese come from? Where did they go? Why didn’t Tower see them? Why didn’t radar? How does a co-pilot with 23 years experience and full aircraft authority fly into an entire flock that he knew were there? How does a P-in-C let this happen?
When geese smash into a jetliner’s windshield at 150kt-180kt closure, as Sullenberger and Skiles claimed happened, they explode on impact leaving a large windswept blood smear that doesn’t get wiped clear by 200kt winds. There was no blood smear on Cactus 1549’s windshield when recovered from the Hudson River. No Hudson water shot over the windshield on landing and if did would’ve partially or totally plunged the aircraft’s nose and cockpit beneath the surface. The underside of the front nose fuselage section acted like a boat hull on touchdown keeping the cabin and windshield on the dry side at all times, thanks to Sullenberger’s controlled landing. The nose on 1549 was blemish-free after coming to a floating halt. All nose damage visible on subsequent photos was caused by police boats and/or ferry boats, the true heroes that afternoon, from either/or banging their vessel into the nose area to stabilize the aircraft so all onboard could be evacuated onto ferries. All leading edge and wingtip damage on the left wing was caused during the understandibly rough and tumble barging process to shore by tugboats and other vessels.
Canada Geese do not just materialize at 2800’ over the Bronx in front of an A320’s super strong goose-proof windshield. It takes many minutes, a great deal longer for these birds to reach this height and cover distance while up there than an A320 climbing at 1800’-2000’/minute and 151-174kt forward speed. From sea level to 2800’ on January 15, 2009, the La Guardia to Bronx skies were clear. Not one cloud wisp to obscure Skiles’ constantly roaming forward, lateral and vertical visibility.
In clear skies, like the afternoon of January 15, 2009, a sizable “perfect formation” of geese, as co-pilot Skiles told the New Scotsman and many other media, would be unmistakable no matter which direction of flight, speed or intercept trajectory to vigilant probing eyes on the flight deck, medium range radar return, La Guardia Tower binoculars, preceding aircraft and scattered remnants easily identifiable by EGF4718 following about two minutes behind.
Skiles, flying the aircraft from the right seat at the time, not only ought to have spotted this perfect formation from safely afar, but in his own words did, and right up until slamming center hole.
There’s an enigma here, several, in fact.
Why didn’t Stiles make any effort to avoid birds that he knew, in his own admission, were there? These birds, if really present, didn’t fly into that Airbus, the Airbus flew into them with Skiles at the sidestick and concentration focused outside the windshield while Sullenberger worked the radios, scanned the glass panels and monitored Skiles.
Why didn’t P-in-C, Sullenberger, make any effort to intervene and circumvent Skiles’ most non-airworthy decision to bullseye an entire flock?
How do legendary super vigilant geese fail to detect and/or make no subsequent effort to scatter in collective defence from a huge, fast approaching menacing predator bearing down on them in perfect visibility?
The CFM 56-5B engines are spaced under the wings just under 36 ½’ on center apart. Enough distance to pack 7-to-10 mature Canada Geese flying head-on in level flight at the engines or rear-ended in wingtip-to-wingtip formation, and even more geese in a T-bone configuration. If the windshield, according to Skiles, “filled up with birds,” a substantial portion of the flock must’ve been nearly 6’ above the wings. How come no geese hit the windshield, radome or wing leading edges? How does a windshield full of geese present one instant, which purportedly caused Sullenberger to instinctively duck, disappear the next?
I might have the answer to all the above:
CFM 56-5B High Pressure Compressor(HPC) Surge and Stall by GE Aviation Design Flaw
The CFM 56-5B has a sordid operational record confirmed by numerous A320 worldwide operator complaints in 2007 about HPC surges and stalls with ineffectual software update 5QB to remedy the irreparable problem.
The CFM 56-5B HPC unit, designed and built by GE Aviation, deteriorates after an unknown but at some definite point number of operational flying hours. There is no known fix beside new engine replacement of at least one engine unit should Exhaust Gas Temperature exceed 75 degrees Celsius during ground test before each departure, as mandated by CFM/GEA/Airbus and EASA “Emergency” maintenance directive.
Two days prior over Newark, the exact 1549 aircraft and engines, also callsign Cactus 1549, since the same milk run, suffered a compressor stall in the *right* engine while climbing to cruise. Passenger, John Hodock, on this flight, told CNN by e-mail: "About 20 minutes after take-off, the plane had a series of compressor stalls on the right engine.” (thanks to a Facebook page for this). The recoverable surge/stall occurred near 28,000’. The crew restarted the engine and continued on to an uneventful landing at its intended destination after originally informing passengers that it would have to return to La Guardia.
The left engine went boom on Cactus 1549 at 2800’. This makes both CFM 56-5Bs encountering total loss of thrust within 48 hours. No wonder the engines were hauled away to GE Aviation’s headquarters in Ohio for teardown. America West (US Airways) replaced a temperature probe on the Newark right engine.
Uh-Oh! Better Get Maaco!
The left photo shows what a bird strike deals out to a little private jet. The force released by a bird hitting an aircraft is ½ bird mass times velocity squared. A haymaker that leaves a crater on impact in the aluminum leading surfaces or edges roughly the size of the bird. Not Cactus 1549, though. As readily seen in the right photo, expand and zoom in your photo viewer whichever way, it is spotless. Not a tell-tale dent or blood smear anywhere indicative of goose strike after purportedly slamming into an entire flock. The photo doesn't show the port side, but if there were dents and blood smear out of view then the NTSB would've mentioned so with photo evidence in support.
There have been about four recorded incidents in jet age civil aviation history of airliners on departure or approach (not takeoff or short final or en route) colliding with an entire flock of birds and occurred because of poor or limited visibility. A Polar Air Cargo 747, flying out of a cloudbank, hit a flock of snow geese on approach to JFK at 7500’ in December, 1995. Neither had a chance to see and avoid. The 747 lost one engine and the leading surfaces and edges were cratered with goose hits that the pilot afterward said sounded like “sandbags.” None of these aircraft, while took a beating, crashed. In 1996, a Belgian military C-130 Hercules collided with a flock on short final and lost three engines. The crew mistakenly aborted the landing and attempted a go-around with the one remaining engine, stalled, crashed, and 34 of the 37 aboard died, including the whole crew.
There has never been an entire flock collision in the departure climb out stage in clear skies by a civil jet airliner. Cactus 1549, as the U.S. corporate media will have it believed, is the first.
Remarkable coincidence for a right engine that surged and stalled with repeated loud popping sounds over Newark 48 hours prior loud enough to jostle slumbering passengers awake and after which USAir only replaced a temperature probe.
A HPC surges when air forcing its way into the business section, the turbojet core, is blocked by a wall of existing air. The core can’t handle the air volume that simultaneously explodes out the back exhaust and front intake. A turbofan is a turbojet with a turbine-driven fan disk that intakes and throws, on the 56-5B, 5.5 more units of air into the bypass air flow region for every 1 unit in the core. Surplus core air collides with existing air and half is forcibly ejected out the direction it came. Forced out at high speed the wrong way out through high and low compressor stages and fan disk intake causing a series of very loud booms per cycle that sound like explosions to those onboard or at a distance. These explosions of supercharged air are occasionally so forceful that the ejected air distorts and destroys blades that trigger a fast domino effect that destroys other blades, progressively destroying the engine. Both recoverable and unrecoverable compressor surges stall and shutdown the engine.
When no damage occurs the engine can be restarted and thereafter operated, as happened 48 hours before over Newark, at reduced N1 without further issue.
There is no imminent need for the crew to do anything other than fly the aircraft and report the incident as soon as possible to ATC after a jarring boom and engine shutdown. It is to the contrary expressly advised to slowly and methodically 100% identify and confirm the actual problem by abnormal event checklist diagnosis and crew resource management. The aircraft’s other remaining engine is more than adequate to remain airborne and, in fact, easily takeoff and climb.
But not 48 hours later over the Bronx. Where there’s one unaddressed HPC stall, there’s always another just around the corner. Slung under the other wing.
The A320 is backup system reinforced to redundancy. It has more back up sensors for every measurable flight and engine perimeter and flight management systems than will ever need. Like a sky diver with a main chute and four backup chutes. The odds of all five chutes failing are astronomical. The CFM 56-5B, however, only has one HPC per engine. There is no backup should it deteriorate in midair. When this HPC deteriorates, that’s it for the engine. The stalled engine, if restart is not possible, becomes a passenger, carried through the air to hopeful uneventful landing by the remaining good engine. Should this remaining engine stall, that’s really it. The aircraft is now a glider, like Cactus 1549.
The same right engine, with new temperature probe, that quit for unknown reason(s) over the Bronx on January 15, 2009, was the same engine that compressor surged and stalled over Newark Jan.13. Same HPC with ineffectual 5BQ software to close the variable stators by 2 additional degrees at low power setting.
An A320 rolls down the runway at takeoff after a gingerly gradual power setting throttled up to about 95%. The crew holds this power setting once airborne until established on a safe climb regimen and then gingerly throttles back, now having attained safe forward momentum, to about 90% and holds this setting all the way to cruise flight level to conserve fuel. On throttle back from 95% to 90% the N1 briefly cuts back to idle, dropping to below low power setting. Herein a mystery occurs inside the CFM 56-5B that stresses and deteriorates the HPC after indeterminate hours of active operation.
A turbofan has to micromanage the air that flows into the core achieved by state of the art computers performing mindboggling fast calculations and adjustments. Not enough air and thrust drops off; too much and it collides with existing air. The CFM 56-5B can’t manage this core flow under certain situations and surges with no known fix other than toss the deteriorated engine and bolt on a new one.
USAir did not replace the engine that stalled over Newark prompting some passengers, literally, to discuss their last will and testament in withdrawn sarcasm and text message next of kin.
Cactus 1549’s left engine emitted a single very loud bang at 2800’, heard by all onboard, and then shutdown. One bang and one only followed by a flameout witnessed by some passengers on the left side. Birds ingested into turbofans do not cause a one-time loud bang. When a bird damages or breaks a blade it causes a series of pops with flame burst each time as the engine is in the midst of progressively disintegrating until shutdown by the pilots. Nothing flew into Cactus 1549’s right engine. There was no loud bang emanating from the right engine or any pops with flame burst. It just shutdown. That’s not a bird strike. It’s a midair engine shutdown by either computer management sensing serious problems inside the unit after the left engine surged and stalled, crew error shutting down the wrong engine, or the engine just packed it in by mechanical or electronic cause.
A flight attendant reported burning metallic or electrical odor. Which engine or other source did it come from? The turbofan bleed air system draws air into the cabin, cargo hold and wings to anti-ice from the low and high pressure compressor stages before the fuel stage. The bleed air is so hot, heated by the compression of ambient air to 40psi, that it must be cooled by dilution with ambient air drawn from the ram air inlets, the ones the 1549 crew forgot to close.
In a compressor surge by blade deterioration, bird strike or other, the exploding air, typically ignited, is blasted past the bleed air inlets at explosive speed with a miniscule amount drawn in the bleed air system then heavily diluted by the packs with ambient air before piped into the cabin. In mere milliseconds after the forward traveling flash burst is over and air is rushing through the engine and out the exhaust at whichever speed it gets by the fan disk or whatever of its blades remain. All raw kerosene jet fuel dumping in the now useless engine is blown out the exhaust, usually ignited forming a flame trail, but nowhere near the bleed air inlets even at severely constrained velocity. Thus not even burnt fuel vapour besides a negligible amount can realistically infiltrate the cabin. Only engine lubricating oil and other liquids via faulty seal(s) can infiltrate from the engine, but at such miniscule parts per million, since so heavily diluted, as to be unnoticeable by the human olfactory system, and why those onboard develop headaches, sore throat, dry itchy skin, and so on, after long flights without ever knowing why. Metallic or electrical odor from within the engines can only emanate from a source upwind of the bleed inlets or from inside the packs or else drawn in through the ram inlets. The ram inlets will draw in the toxic plumes of ground-based electrical fires, and air pollution, though so improbable as to be next to impossible that this is what occurred. The reported odor was so pungent as to imply cabin fire. One flight attendant called for a fire extinguisher. It’ll be interesting to learn the source of this odor and if and how connected to the loud boom.
However civil-minded and composed passengers normally are, once a captain declares “brace for impact” a whole new set of rules begin to apply. Once thousands of gallons of frigid Hudson water rush in, submerging passengers from the ankles to their chest, especially toward the back of coach, it’s a free for all melee to the closest exit. Terrified passengers clawed over the seats, shouting, wanting nothing other than running like hell toward and out the closest door. Only two forward and one aft attendant to instruct and regulate the evacuation of 150 passengers would be an impossible onus. They tried as best as possible. Once outside standing on the wings, feet and legs rapidly numbing, strength and balance waning, with many already drenched while inside, the sight of approaching Hudson ferries must’ve been sheer elation. In the wind down once aboard these rescue boats to reaching shore and taken to 42nd Street, reality began to settle in with pointed, awkward questions forming. How did this happen?
One fact is certain. If geese did hit that plane, it would be the least of the plane's inherent problems.
Thursday, April 2, 2009
American Airlines Flight 587
American Airlines Flight 587 (AAL587), registered as N14053, an Airbus Industrie A300-605R, crashed in Belle Harbor, Queens, New York on November 12, 2001, killing all 260 onboard, 5 on the ground and injuring 1 ground survivor, nearly a month to the day after September 11, 2001 with public belief of a second terrorist attack overpowering.
Not long after the crash the U.S. Army Corps of Engineers found the A300’s vertical stabilizer, minus rudder, floating in Jamaica Bay and the focus turned from terrorism to the aircraft and crew. The NTSB investigated and eventually blamed the co-pilot, Sten Molin, and Airbus rudder design as “Probable Cause”: http://www.ntsb.gov/publictn/2004/AAR0404.pdf (a must read to understand the background of the incident and this article).
The NTSB report, which makes no effort to name the flight crew, is possibly the most unpardonable railroading of innocent casualties doomed by a previously damaged aircraft who did nothing amiss to merit their fate. The captain was Ed States and first officer was Sten Molin.
AAR0404, aside from the above, is an excellent report, excluding its fictitious wake turbulence and allotment of blame, namely in its detail of the “Progressive Failure” of AAL587’s tail fin. The fin didn’t snap off in one go; its main and transverse mounts progressively failed beginning at the aft and progressing to the fore in two separate stages with the second episode occurring roughly 15 seconds after the first.
This article highlights the physical improbabilities, to put it politely, of the NTSB’s “Probable Cause” conclusions authored to neatly absolve American Airlines of the real responsibility for the disaster: AAL’s failure to repair latent damage in N14053’s empennage tail fin mounts caused by a brutal encounter with clear air turbulence over the Caribbean in 1994.
The NTSB accident report alleges that AAL587 encountered wake turbulence from a Boeing 747, Japan Airlines Flight 47 (JAL47), after takeoff from JFK runway 31L on 11/12/01 and the co-pilot’s rudder pedal inputs to evade the turbulence fatally stressed the vertical stabilizer to catastrophic destruction, all permitted to occur by the Airbus rudder design.
The laws of physics dismiss the NTSB’s wake turbulence claim and the A300 worldwide fleet operational history dismisses the co-pilot rudder input/sideslip story.
Great briefer on wake turbulence right here: http://www.scribd.com/doc/3996595/AC9023F-Wake-Turbulence
AAL587 took off from Runway 31L about 1m40s behind JAL47 and maintained this interval throughout. Runway 31L faces Manhattan so aircraft heading to southerly or easterly destinations are required to commence an abrupt left turn after wheels up to Canarsie VOR (CRI) or the BRIDGE non-directional beacon (NDB). JAL47 flew the wider Breezy Point Climb toward CRI and AAL587 flew the tighter inside arc Bridge Climb toward BRIDGE. AAL587 never neared within 1nm laterally of JAL47’s departure route or any height close to the 747’s wake turbulence sink window. The prevailing winds and direction were nowhere near strong enough to push the 747’s rapidly dissipating vortices into AAL587’s path and altitude. In short, there wasn’t any wake turbulence to encounter.
Both the A300 and 747 are ‘Heavy’ class aircraft with the 747 the heavier of the two; meaning that the A300 can fly into and withstand a 747 wake turbulence thrashing without much ado. Under Federal Aviation Administration wake turbulence separation rules, heavy aircraft are required to maintain minimum 4nm abaft any immediately preceding heavy.
AAL547 never approached within 5nm of JAL47, never approached within 1nm lateral and always maintained 2000’ or greater vertical separation at every secondary radar return of the way as unmistakably clear on the NTSB report’s superimposed flight paths of the two aircraft.
Wake turbulence is at its most perilous, as the above link explains, from “HEAVY-SLOW-CLEAN” aircraft. This turbulence also rapidly dissipates after generation and sinks in the region of 500’-to-900’/minute. A heavy 747 (A380 jumbo-class didn’t exist yet) aircraft flying slow speed in clean configuration produced the greatest wake turbulence in civil aviation, rapidly dissipating while sinking at the maximum rate. The wingtip vortices are the largest component of this turbulence by far and they begin generating spirals just as the aircraft becomes airborne. Spirals don’t generate on takeoff roll because the tarmac impedes their formation. On Nov. 12, 2001, the most perilous wake turbulence from JAL47 was generated after takeoff at V2 and reached peak strength after the crew soon retracted gear then takeoff flaps while on or around V2 accelerating toward 250kt. AAL587 flew past JAL47’s peak wake turbulence region without a bump.
The highest wind recording at JFK a half hour before AAL587 lined up on 31L was 20kt and this dropped to 10kt by the time the A300 took off. The left wingtip vortices of JAL47 moved at the vortices’ outward and upward rotational velocity against a 10kt headwind. On gear up and flap retraction into this headwind the left and right vortex rotational speed was circa 180kt/h at point of generation and moving outward and upward perpendicular to the aircraft’s direction of travel while pushed backward by 10kt/hour headwind. When the 747 turned left toward CRI turning out of a 10kt headwind into a 10kt crosswind, the left wingtip vortices spiraled outward and upward at initial vortex generation speed with the bottom half moving rotation speed plus 10kt and the top half battling the 10kt wind and oblating, increasing in diameter to no greater than the 747 wingspan with the left vortex trail pushed southerly at 10kt/h. As this occurred, the right wingtip vortices slammed into the 10kt wind. Both rapidly lost energy while sinking, since heavy, at circa 900’/minute for 1080’ descent in the 1m40s separation between the two aircraft. After the 747 had traveled 5nm the vortices generated 1m40s earlier were now completely dissipated and blended into the atmospheric turbulence of a 10kt wind almost 1000’ above AAL587’s route at every step of the way and more than 0.5nm off the A300’s right wing.
The wake turbulence thrown off by a 747 on takeoff hit peak strength under zero wind. There is no atmospheric turbulence in calm wind conditions vortices to crash into and additionally dissipate the sinking vortices which are free to rotate in increasingly larger spirals until using up their energy.
Airline Transport Pilots know wake turbulence when they encounter it. The first officer’s “What the hell are we into[?],” recorded on the HOT-2 mic, suggest that the crew, since at a loss to explain their predicament, were in uncharted territory of airframe dynamics.
At 9:15:36am EST, something big and very loud rocked AAL587 at 1750’ in a climb and 250kt and couldn’t have been wake turbulence, or collision with another aircraft or any airborne object. The first loud bang was the rear vertical stabilizer right side main lug mount snapping in half. The next loud bang seconds later was the remainder of the stabilizer mounts progressively and swiftly ripped in two or else torn from the empennage while still attached to the fin. The vertical stabilizer was gone and the aircraft was now uncontrollable.
The destruction of the right rear main lug severely compromised the vertical stabilizer mounting strength. It was no longer a match for any rudder deflection. Being broken now the fin was subject to greatly enhanced torsion and flex by even minimal rudder deflection, lethally vulnerable against the forces of 250kt relative wind from substantially reduced mounting strength to hold down in place. Like a structurally critical but flawed building crane tie-on strap snapping, causing the crane to keel over, overstressing and snapping all other straps, pitching and burying the crane no longer tied to the building into a condo across the street as occurred in New York City over a year ago. Or damaged rudder mount on a sailboat. Turn the tiller and the rudder is torn free from the transom or rendered useless.
The lug fracture, in conjunction with the co-pilot and captain’s zero awareness of the dire circumstance and co-pilot’s unwitting continued rudder use, created a domino effect that eventually tore the fin off without either pilot ever knowing why.
After the catastrophe, the NTSB went into the simulator, based on presumed wake turbulence, negligent co-pilot rudder conduct and completely airworthy aircraft, and sought out means to graphically depict how the co-pilot could rip a tail fin out of an airworthy aircraft at 250kt. This trial by computer simulation from unsubstantiated presumptions is an excellent example of ‘Begging the Question’. This was no impartial investigation. The NTSB ruled the aircraft certified airworthy doomed by the co-pilot “overreact[ing]” to wake turbulence along with the insinuation that Airbus’ rudder design enabled pilot overuse and abuse without adequate damper restraint.
The Flight Data Recorder and American Airline’s aircraft operational history and maintenance records dismiss this second conclusion acquired by manipulative human intervention via creative computer simulation.
The A300 rudder deflected a maximum 9.3 degrees at 250kt by automatic damper restraint. The rudder pedals on AAL587 extended 4” in either direction from neutral. The co-pilot’s right and left pedal inputs never exceeded 2” of movement in unison with equal direction yoke movement, until after the fin was gone and the co-pilot, still unaware, applied the full 4” travel in desperation to maintain level controlled flight, holding it there until impact, all in vain.
At only one instance, lasting one second, did the co-pilot induce sideslip with 1.6”-2” of right rudder in contrast to 30 degrees left aileron, a non-issue for an airworthy A300 fin but calamitous for a severely weakened mounting system in induced sideslip or not. The co-pilot’s rudder deflections exacerbated an already dire predicament not of the co-pilot’s doing. There were no rudder inputs, none at least published by the NTSB, preceding the initial bang that triggered the co-pilot to apply rudder inputs.
The NTSB accident report maintains that the co-pilot “overreact[ed]” with “cyclic rudder motions” that were “too aggressive, and…unnecessary.” The aircraft was “certified” “airworthy” with a rudder design “susceptible” to “potentially hazardous rudder inputs.”
The co-pilot reacted to a major unexpected roll event, not caused by turbulence but by the tail fin systematically tearing off, and tore off because the same empennage was hammered by severe clear air turbulence in 1994 and the latent damage induced in result never even inspected.
From 1995-2001, twelve Service Difficulty Reports from A300 operators worldwide involving the aircraft’s empennage were filed with the Federal Aviation Administration. There were no details of which components of A300 empennages specifically encountered service difficulty but no trends were identified. None involved the fin mounts or the NTSB report would’ve indicated so, and each difficulty, whatever they were, were satisfactorily addressed by subsequent maintenance/repair. (p.41)
There was no filing of any SDR by American Airlines about the 1994 turbulence incident over the Caribbean because AAL never even notified the FAA.
47 of 221 onboard were injured by powerful invisible air currents en route to Puerto Rico, the plane managed to landed uneventfully and AAL never submitted so much as the flight number or date.
The only evidence of any post-incident diligence by AAL are maintenance hub “work cards” announcing intended future plans that the “vertical stabilizer torque box was to be inspected externally for distortion, cracks, pulled or torn fasteners, or damaged paint.” (“was to be” the key words) The ‘was to be’ which never was also included external inspection of the rudder system, and if any damage was visually discovered, the full slate of internal inspection would follow. No work card of this tentative planned inspection was submitted to the FAA either. There is no record on AAL company file, SDR or maintenance work card that any inspection even occurred.
Yet on the basis of mere work cards only announcing a planned inspection, as opposed to concrete proof of full teardown and meticulous microscopic examination of every cubic nanometer with 47 physical injuries of varying severity as all the impetus necessary, the NTSB report insists that AAL did carry out a “special inspection.” Only the NTSB has no record to back this claim, since none was ever filed. A most unprecedented assertion by the NTSB.
The simplest answer is that no external inspection ever occurred. If did, there would be work cards on record as proof, SDR or not, and the FAA, therefore NTSB, would have these and would’ve included them in AAR0404, which they didn’t.
No inspection occurred because AAL never bothered to perform one. The aircraft was immediately returned to service after landing in Puerto Rico. From the remainder of 1994 to November 12, 2001, whatever latent difficulties incurred by that clear air turbulence remained in the aircraft’s empennage unchecked. Every subsequent departure was a macabre lottery and AAL587 happened to draw the short straw.
The legendary story of United 232 in 1989, a DC-10 that crash landed in Sioux City, Iowa, demonstrated that a microscopic crack, invisible to extensively trained, highly experienced, especially vigilant maintenance staff, and in this case the tail engine fan disk, can bring down an aircraft after thousands of service hours from the tiniest latent flaw with no warning.
The Caribbean clear air turbulence incident must’ve damaged one or more of AAL587’s vertical stabilizer mounts with the tail fin most vulnerable and taking brunt of abuse. All it takes is a microscopic crack in one mount exposed to seven years of normal usage, numerous other turbulence encounters, maybe even a tail strike or two, to eventually fail. None of the latent damage was detectable by walk around inspection or internal visual inspection, but only by complete tear down of the entire empennage and full spectrum technology examination of every cubic micron. It never happened. Moreover, the paint on these aircraft is so flexible and resilient that it can survive cracking even after tremendous abuse as the recent Fed-X MD-11 crash in Narita shows. Hence checking for and finding no paint cracks, indicate nothing.
Airline transport vertical stabilizers are so tough that it takes incredible abuse to defeat them, and 4 degree or 11 degree sideslip at 250kt in 11-22kt wind (see report) just isn’t going to win the battle, nor the energy released by clear air turbulence powerful enough to send 47 walking wounded or on ambulance stretcher passengers to Puerto Rico hospital emergency rooms.
In a tragic 2002 midair t-bone at 35,000’ near Uberlingen, Germany, the vertical stabilizer of a pressurized Boeing 757 cargo flight tore a pressurized Tupolev Tu-154M in half, both traveling at cruise Mach, roughly 480kts ground speed, perpendicular to the other. The top 80% of the 757’s fin with rudder was sheared off but the mountings, as if matters now, held in place. Not even the high speed ground impact through big unyielding trees separated the mounts from the empennage. A tragedy that macabre demonstrated the strength of these mountings and the extreme unlikelihood of the NTSB’s preconceived simulated AAL587 conclusions.
There has never been a rudder pedal-induced separation of an A300 fin at 250kt, even amid severe turbulence. And if 2” of right rudder pedal input producing 4.65 degree rudder deflection in a 4-11 degree left sideslip in a 25 degree left roll, were catastrophic abuse, the entire A300 fleet, starting with the original test flights, would’ve crashed years ago. As each of these aircraft have been subject to the identical cyclic rudder/aileron configurations as AAL587 was many, many times over. The difference being: these other A300 empennages weren’t hammered by devastating clear air turbulence.
The AAL587 fin minus rudder, spotted by the U.S. Army floating in Jamaica Bay, had plummeted untold hundreds of feet, smashing into the brick-like water, rapidly descending below the surface, and floated back up essentially unscathed. The rudder, likely first to hit, was torn off on water impact. Soon after the discovery the NTSB found another U.S. airline transport pilot, as the mortal remains of the co-pilot and the 264 other victims filled a makeshift morgue, to go on record, anonymously, and criticize the co-pilot Molin as a rudder-aggressive loose cannon while tactfully balancing this out with complements from a different captain and a flight engineer. The critic captain never bothered, possibly due to forgot, to file any complaint or concern with the airline or FAA at any point prior to the crash. If the co-pilot really were loose cannon, AAL would know about it, as would the pilot-in-command that day. Thus, why would AAL employ the co-pilot armed with this knowledge of unpredictable volatility and, if did, why would the captain let them fly the aircraft that morning?
The answer, once again, is simple. The co-pilot was the opposite of loose cannon. AAR0404 is gross character assassination of unjustifiably deceased via computer simulated artifact of what didn’t happen.
The only causal factors to ever tear the vertical stabilizer off an airline transport jet in midair, dooming the aircraft, were midair collision or hidden structural flaw, both the consequence of multi party human error and oversight.
Contrary to the NTSB, AAL587 was ultimately doomed by damage incurred from severe clear air turbulence in 1994, seven years of subsequent service, and American Airlines’ failure to diligently address, identify and repair latent microscopic cracks in the aircraft’s vertical stabilizer mounts that eventually failed. The co-pilot and 264 others, including 5 on the ground in Belle Harbor, were the innocent human casualties. Each had a name, family, friends, a past. What they didn’t have was an independent U.S. federal government agency, charged with the responsibility of ensuring and promoting aviation safety, shouting down and fending off powerful lobbying pressure to blame everyone but the entity genuinely culpable: American Airlines.
American Airlines’ failure to diligently inspect and repair structural empennage damage to N14053 incurred from clear air turbulence over the Caribbean in 1994 led to the preventable deaths of 265 people on November 12, 2001 in Belle Harbor, NY.
Not long after the crash the U.S. Army Corps of Engineers found the A300’s vertical stabilizer, minus rudder, floating in Jamaica Bay and the focus turned from terrorism to the aircraft and crew. The NTSB investigated and eventually blamed the co-pilot, Sten Molin, and Airbus rudder design as “Probable Cause”: http://www.ntsb.gov/publictn/2004/AAR0404.pdf (a must read to understand the background of the incident and this article).
The NTSB report, which makes no effort to name the flight crew, is possibly the most unpardonable railroading of innocent casualties doomed by a previously damaged aircraft who did nothing amiss to merit their fate. The captain was Ed States and first officer was Sten Molin.
AAR0404, aside from the above, is an excellent report, excluding its fictitious wake turbulence and allotment of blame, namely in its detail of the “Progressive Failure” of AAL587’s tail fin. The fin didn’t snap off in one go; its main and transverse mounts progressively failed beginning at the aft and progressing to the fore in two separate stages with the second episode occurring roughly 15 seconds after the first.
This article highlights the physical improbabilities, to put it politely, of the NTSB’s “Probable Cause” conclusions authored to neatly absolve American Airlines of the real responsibility for the disaster: AAL’s failure to repair latent damage in N14053’s empennage tail fin mounts caused by a brutal encounter with clear air turbulence over the Caribbean in 1994.
The NTSB accident report alleges that AAL587 encountered wake turbulence from a Boeing 747, Japan Airlines Flight 47 (JAL47), after takeoff from JFK runway 31L on 11/12/01 and the co-pilot’s rudder pedal inputs to evade the turbulence fatally stressed the vertical stabilizer to catastrophic destruction, all permitted to occur by the Airbus rudder design.
The laws of physics dismiss the NTSB’s wake turbulence claim and the A300 worldwide fleet operational history dismisses the co-pilot rudder input/sideslip story.
Great briefer on wake turbulence right here: http://www.scribd.com/doc/3996595/AC9023F-Wake-Turbulence
AAL587 took off from Runway 31L about 1m40s behind JAL47 and maintained this interval throughout. Runway 31L faces Manhattan so aircraft heading to southerly or easterly destinations are required to commence an abrupt left turn after wheels up to Canarsie VOR (CRI) or the BRIDGE non-directional beacon (NDB). JAL47 flew the wider Breezy Point Climb toward CRI and AAL587 flew the tighter inside arc Bridge Climb toward BRIDGE. AAL587 never neared within 1nm laterally of JAL47’s departure route or any height close to the 747’s wake turbulence sink window. The prevailing winds and direction were nowhere near strong enough to push the 747’s rapidly dissipating vortices into AAL587’s path and altitude. In short, there wasn’t any wake turbulence to encounter.
Both the A300 and 747 are ‘Heavy’ class aircraft with the 747 the heavier of the two; meaning that the A300 can fly into and withstand a 747 wake turbulence thrashing without much ado. Under Federal Aviation Administration wake turbulence separation rules, heavy aircraft are required to maintain minimum 4nm abaft any immediately preceding heavy.
AAL547 never approached within 5nm of JAL47, never approached within 1nm lateral and always maintained 2000’ or greater vertical separation at every secondary radar return of the way as unmistakably clear on the NTSB report’s superimposed flight paths of the two aircraft.
Wake turbulence is at its most perilous, as the above link explains, from “HEAVY-SLOW-CLEAN” aircraft. This turbulence also rapidly dissipates after generation and sinks in the region of 500’-to-900’/minute. A heavy 747 (A380 jumbo-class didn’t exist yet) aircraft flying slow speed in clean configuration produced the greatest wake turbulence in civil aviation, rapidly dissipating while sinking at the maximum rate. The wingtip vortices are the largest component of this turbulence by far and they begin generating spirals just as the aircraft becomes airborne. Spirals don’t generate on takeoff roll because the tarmac impedes their formation. On Nov. 12, 2001, the most perilous wake turbulence from JAL47 was generated after takeoff at V2 and reached peak strength after the crew soon retracted gear then takeoff flaps while on or around V2 accelerating toward 250kt. AAL587 flew past JAL47’s peak wake turbulence region without a bump.
The highest wind recording at JFK a half hour before AAL587 lined up on 31L was 20kt and this dropped to 10kt by the time the A300 took off. The left wingtip vortices of JAL47 moved at the vortices’ outward and upward rotational velocity against a 10kt headwind. On gear up and flap retraction into this headwind the left and right vortex rotational speed was circa 180kt/h at point of generation and moving outward and upward perpendicular to the aircraft’s direction of travel while pushed backward by 10kt/hour headwind. When the 747 turned left toward CRI turning out of a 10kt headwind into a 10kt crosswind, the left wingtip vortices spiraled outward and upward at initial vortex generation speed with the bottom half moving rotation speed plus 10kt and the top half battling the 10kt wind and oblating, increasing in diameter to no greater than the 747 wingspan with the left vortex trail pushed southerly at 10kt/h. As this occurred, the right wingtip vortices slammed into the 10kt wind. Both rapidly lost energy while sinking, since heavy, at circa 900’/minute for 1080’ descent in the 1m40s separation between the two aircraft. After the 747 had traveled 5nm the vortices generated 1m40s earlier were now completely dissipated and blended into the atmospheric turbulence of a 10kt wind almost 1000’ above AAL587’s route at every step of the way and more than 0.5nm off the A300’s right wing.
The wake turbulence thrown off by a 747 on takeoff hit peak strength under zero wind. There is no atmospheric turbulence in calm wind conditions vortices to crash into and additionally dissipate the sinking vortices which are free to rotate in increasingly larger spirals until using up their energy.
Airline Transport Pilots know wake turbulence when they encounter it. The first officer’s “What the hell are we into[?],” recorded on the HOT-2 mic, suggest that the crew, since at a loss to explain their predicament, were in uncharted territory of airframe dynamics.
At 9:15:36am EST, something big and very loud rocked AAL587 at 1750’ in a climb and 250kt and couldn’t have been wake turbulence, or collision with another aircraft or any airborne object. The first loud bang was the rear vertical stabilizer right side main lug mount snapping in half. The next loud bang seconds later was the remainder of the stabilizer mounts progressively and swiftly ripped in two or else torn from the empennage while still attached to the fin. The vertical stabilizer was gone and the aircraft was now uncontrollable.
The destruction of the right rear main lug severely compromised the vertical stabilizer mounting strength. It was no longer a match for any rudder deflection. Being broken now the fin was subject to greatly enhanced torsion and flex by even minimal rudder deflection, lethally vulnerable against the forces of 250kt relative wind from substantially reduced mounting strength to hold down in place. Like a structurally critical but flawed building crane tie-on strap snapping, causing the crane to keel over, overstressing and snapping all other straps, pitching and burying the crane no longer tied to the building into a condo across the street as occurred in New York City over a year ago. Or damaged rudder mount on a sailboat. Turn the tiller and the rudder is torn free from the transom or rendered useless.
The lug fracture, in conjunction with the co-pilot and captain’s zero awareness of the dire circumstance and co-pilot’s unwitting continued rudder use, created a domino effect that eventually tore the fin off without either pilot ever knowing why.
After the catastrophe, the NTSB went into the simulator, based on presumed wake turbulence, negligent co-pilot rudder conduct and completely airworthy aircraft, and sought out means to graphically depict how the co-pilot could rip a tail fin out of an airworthy aircraft at 250kt. This trial by computer simulation from unsubstantiated presumptions is an excellent example of ‘Begging the Question’. This was no impartial investigation. The NTSB ruled the aircraft certified airworthy doomed by the co-pilot “overreact[ing]” to wake turbulence along with the insinuation that Airbus’ rudder design enabled pilot overuse and abuse without adequate damper restraint.
The Flight Data Recorder and American Airline’s aircraft operational history and maintenance records dismiss this second conclusion acquired by manipulative human intervention via creative computer simulation.
The A300 rudder deflected a maximum 9.3 degrees at 250kt by automatic damper restraint. The rudder pedals on AAL587 extended 4” in either direction from neutral. The co-pilot’s right and left pedal inputs never exceeded 2” of movement in unison with equal direction yoke movement, until after the fin was gone and the co-pilot, still unaware, applied the full 4” travel in desperation to maintain level controlled flight, holding it there until impact, all in vain.
At only one instance, lasting one second, did the co-pilot induce sideslip with 1.6”-2” of right rudder in contrast to 30 degrees left aileron, a non-issue for an airworthy A300 fin but calamitous for a severely weakened mounting system in induced sideslip or not. The co-pilot’s rudder deflections exacerbated an already dire predicament not of the co-pilot’s doing. There were no rudder inputs, none at least published by the NTSB, preceding the initial bang that triggered the co-pilot to apply rudder inputs.
The NTSB accident report maintains that the co-pilot “overreact[ed]” with “cyclic rudder motions” that were “too aggressive, and…unnecessary.” The aircraft was “certified” “airworthy” with a rudder design “susceptible” to “potentially hazardous rudder inputs.”
The co-pilot reacted to a major unexpected roll event, not caused by turbulence but by the tail fin systematically tearing off, and tore off because the same empennage was hammered by severe clear air turbulence in 1994 and the latent damage induced in result never even inspected.
From 1995-2001, twelve Service Difficulty Reports from A300 operators worldwide involving the aircraft’s empennage were filed with the Federal Aviation Administration. There were no details of which components of A300 empennages specifically encountered service difficulty but no trends were identified. None involved the fin mounts or the NTSB report would’ve indicated so, and each difficulty, whatever they were, were satisfactorily addressed by subsequent maintenance/repair. (p.41)
There was no filing of any SDR by American Airlines about the 1994 turbulence incident over the Caribbean because AAL never even notified the FAA.
47 of 221 onboard were injured by powerful invisible air currents en route to Puerto Rico, the plane managed to landed uneventfully and AAL never submitted so much as the flight number or date.
The only evidence of any post-incident diligence by AAL are maintenance hub “work cards” announcing intended future plans that the “vertical stabilizer torque box was to be inspected externally for distortion, cracks, pulled or torn fasteners, or damaged paint.” (“was to be” the key words) The ‘was to be’ which never was also included external inspection of the rudder system, and if any damage was visually discovered, the full slate of internal inspection would follow. No work card of this tentative planned inspection was submitted to the FAA either. There is no record on AAL company file, SDR or maintenance work card that any inspection even occurred.
Yet on the basis of mere work cards only announcing a planned inspection, as opposed to concrete proof of full teardown and meticulous microscopic examination of every cubic nanometer with 47 physical injuries of varying severity as all the impetus necessary, the NTSB report insists that AAL did carry out a “special inspection.” Only the NTSB has no record to back this claim, since none was ever filed. A most unprecedented assertion by the NTSB.
The simplest answer is that no external inspection ever occurred. If did, there would be work cards on record as proof, SDR or not, and the FAA, therefore NTSB, would have these and would’ve included them in AAR0404, which they didn’t.
No inspection occurred because AAL never bothered to perform one. The aircraft was immediately returned to service after landing in Puerto Rico. From the remainder of 1994 to November 12, 2001, whatever latent difficulties incurred by that clear air turbulence remained in the aircraft’s empennage unchecked. Every subsequent departure was a macabre lottery and AAL587 happened to draw the short straw.
The legendary story of United 232 in 1989, a DC-10 that crash landed in Sioux City, Iowa, demonstrated that a microscopic crack, invisible to extensively trained, highly experienced, especially vigilant maintenance staff, and in this case the tail engine fan disk, can bring down an aircraft after thousands of service hours from the tiniest latent flaw with no warning.
The Caribbean clear air turbulence incident must’ve damaged one or more of AAL587’s vertical stabilizer mounts with the tail fin most vulnerable and taking brunt of abuse. All it takes is a microscopic crack in one mount exposed to seven years of normal usage, numerous other turbulence encounters, maybe even a tail strike or two, to eventually fail. None of the latent damage was detectable by walk around inspection or internal visual inspection, but only by complete tear down of the entire empennage and full spectrum technology examination of every cubic micron. It never happened. Moreover, the paint on these aircraft is so flexible and resilient that it can survive cracking even after tremendous abuse as the recent Fed-X MD-11 crash in Narita shows. Hence checking for and finding no paint cracks, indicate nothing.
Airline transport vertical stabilizers are so tough that it takes incredible abuse to defeat them, and 4 degree or 11 degree sideslip at 250kt in 11-22kt wind (see report) just isn’t going to win the battle, nor the energy released by clear air turbulence powerful enough to send 47 walking wounded or on ambulance stretcher passengers to Puerto Rico hospital emergency rooms.
In a tragic 2002 midair t-bone at 35,000’ near Uberlingen, Germany, the vertical stabilizer of a pressurized Boeing 757 cargo flight tore a pressurized Tupolev Tu-154M in half, both traveling at cruise Mach, roughly 480kts ground speed, perpendicular to the other. The top 80% of the 757’s fin with rudder was sheared off but the mountings, as if matters now, held in place. Not even the high speed ground impact through big unyielding trees separated the mounts from the empennage. A tragedy that macabre demonstrated the strength of these mountings and the extreme unlikelihood of the NTSB’s preconceived simulated AAL587 conclusions.
There has never been a rudder pedal-induced separation of an A300 fin at 250kt, even amid severe turbulence. And if 2” of right rudder pedal input producing 4.65 degree rudder deflection in a 4-11 degree left sideslip in a 25 degree left roll, were catastrophic abuse, the entire A300 fleet, starting with the original test flights, would’ve crashed years ago. As each of these aircraft have been subject to the identical cyclic rudder/aileron configurations as AAL587 was many, many times over. The difference being: these other A300 empennages weren’t hammered by devastating clear air turbulence.
The AAL587 fin minus rudder, spotted by the U.S. Army floating in Jamaica Bay, had plummeted untold hundreds of feet, smashing into the brick-like water, rapidly descending below the surface, and floated back up essentially unscathed. The rudder, likely first to hit, was torn off on water impact. Soon after the discovery the NTSB found another U.S. airline transport pilot, as the mortal remains of the co-pilot and the 264 other victims filled a makeshift morgue, to go on record, anonymously, and criticize the co-pilot Molin as a rudder-aggressive loose cannon while tactfully balancing this out with complements from a different captain and a flight engineer. The critic captain never bothered, possibly due to forgot, to file any complaint or concern with the airline or FAA at any point prior to the crash. If the co-pilot really were loose cannon, AAL would know about it, as would the pilot-in-command that day. Thus, why would AAL employ the co-pilot armed with this knowledge of unpredictable volatility and, if did, why would the captain let them fly the aircraft that morning?
The answer, once again, is simple. The co-pilot was the opposite of loose cannon. AAR0404 is gross character assassination of unjustifiably deceased via computer simulated artifact of what didn’t happen.
The only causal factors to ever tear the vertical stabilizer off an airline transport jet in midair, dooming the aircraft, were midair collision or hidden structural flaw, both the consequence of multi party human error and oversight.
Contrary to the NTSB, AAL587 was ultimately doomed by damage incurred from severe clear air turbulence in 1994, seven years of subsequent service, and American Airlines’ failure to diligently address, identify and repair latent microscopic cracks in the aircraft’s vertical stabilizer mounts that eventually failed. The co-pilot and 264 others, including 5 on the ground in Belle Harbor, were the innocent human casualties. Each had a name, family, friends, a past. What they didn’t have was an independent U.S. federal government agency, charged with the responsibility of ensuring and promoting aviation safety, shouting down and fending off powerful lobbying pressure to blame everyone but the entity genuinely culpable: American Airlines.
American Airlines’ failure to diligently inspect and repair structural empennage damage to N14053 incurred from clear air turbulence over the Caribbean in 1994 led to the preventable deaths of 265 people on November 12, 2001 in Belle Harbor, NY.
Saturday, March 21, 2009
The Incredible (Formerly Invisible) Materializing Canada Goose Feather
There are no errant bird feathers or organic bird matter in the Hudson River.
Only H2O with a dash of sea salt. The U.S. National Transportation Safety Board is tacitly clear on this.
In the NTSB’s view Cactus 1549 plunked down into cleaner than natural spring water Hudson H2O with a dash of salt. Since no bird feathers and organic bird matter exist in the Hudson, at least not under NTSB ecology rules, all feather and organic bird matter discovered in Cactus 1549’s engines had to be brought and introduced to the river by these engines that ingested the feathers at 2800’ over the Bronx, making their introduction an ecological and Neornithe first in Hudson River history.
The Airbus Industrie 320 touches down on runways at 140kt to the relative wind when landing, give or take 5kt. In metric conversion just under 260km/h and essentially the speed that Cactus 1549 with a slight tail/cross wind combo touched down on the Hudson with the empennage underside contacting first, then more of the underside, then both engines gulping in crystal clear refreshing Hudson H2O with a pinch of salt under NTSB rules since the bottom hemispheric half of the engine intakes are slung beneath the fuselage bottom. http://www.airliners.net/aircraft-data/stats.main?id=23
A decent dishwasher shoots hot water at dishes and cutlery at about 70kt from pinholes on the spray armature(s). The CFM (Snecma and GE Aviation) 56-5B turbofan front intake diameter is nearly as wide as the average human adult is tall, it can accommodate hundreds of thousands of tiny dishwasher water jet sprays to form essentially a mini tsunami, and at 140kt this CFM dishwasher is a super industrial plate rinser. The inrush force of thousands of gallons of water at 140kt, tearing through the intake fan blades, outer bypass areas, with core water compressed by the Venturi of the compressor stages, will clean the most stubborn stain in its path if wasn’t already destroyed and ejected by prior violent midair compressor surge.
Bird feathers won’t be sticking around inside this dishwasher very long.
But apparently this feather did, a Canada Goose feather supplied, you guessed it, by the NTSB, supposedly discovered in Cactus 1549’s left engine outer bypass flow path on January 29, 2009 or as bag label suggests. Notice the yellow plastic ruler: “Report Strikes: http//wildlife-mitigatio[n]…Bird Strike Committee USA 20[XX]”? Of all the potential rulers to use, how convenient.
This 4” feather would weigh in the single grams bone dry. It somehow got snagged in the bypass which doesn’t have entangling appendages since designed to handle continuous 480kt air current at cruise speed and aerodynamically streamlined for minimal possible drag, that withstood over two minutes of 180-200kt wind blast and then 140kt tsunami of, getting back to reality, murky Hudson River goop. Where would it snag in the outer bypass and how? And after snagging how would it stick around in 200kt wind? And after somehow surviving the 200kt tornado, how would it survive a 140kt bath?
The Incredibly Materializing Previously Invisible Bird Matter in NTSB press advisory chronology:
“A visual examination of the [#1 or left] engine did not reveal evidence of organic material[Italics mine]; there was evidence of soft body impact damage.” (NTSB ‘Second Update’ Jan. 24, 2009)
Impact damage after a 140kt wet Big Apple welcome, you don’t say? An army of NTSB inspectors poured over this engine from the afternoon of Jan. 23 onward, the unit recovered off the river bottom, and were unable to spot any evidence of goose matter after hours of intense examination.
“The left (#1) engine, which was recovered from the Hudson River on January 23 and subsequently shipped to the manufacturer in Cincinnati where the NTSB is directing a teardown, was found to contain bird remains. The organic material found in the right (#2) engine has also been confirmed to be bird remains. [Third Update, Feb. 4, 2009].
Going from “did not reveal” to “found to contain remains”
missed on the 23rd-24th of January but yet remarkably discovered some days later. Again, how convenient.
“The bird remains found in both engines of US Airways flight 1549 have been identified by the Smithsonian Institution's Feather Identification Laboratory as Canada Goose (Branta canadensis).” [Fourth Update, Feb. 12, 2009]
Have to hand it to the NTSB, it’s tough to spin whoppers, but they try.
Critical to understanding the NTSB slight of hand, this Board claimed to find only feathers and feather fragments. Not goose blood and the only organic matter besides tissue in which a forensic DNA lab can compile a DNA ‘barcode’ and compare to known geese DNA in their database.
By the Smithsonian bird strike lab’s admission, viable DNA is typically only found in 52.6% of all blood and tissue samples that arrive to their lab within one week of the bird strike event; and in 68% of all blood and tissue samples stretching out to the full 116 day Smithsonian study limit. For some reason the longer the wait the more viable the DNA. Without viable DNA the best precision the Smithsonian can attain are Order and Family. But Branta is the genus, canadensis the species and Branta canadensis belongs to the family Anatidae which contains 146 different species in 40 genera. No goose blood or tissue were recovered, only feathers and feather fragments, ruling out any chance that the Smithsonian Feather Lab or any other DNA-identified them as Canada Geese.
“DNA analysis is only used in birdstrike cases that have blood, tissue or if the identification cannot be made based on feather morphology. Furthermore, viable DNA is not found in approximately 32% of the cases (Dove et al., MS in prep, 2007) and the identifications are made mainly to the Order and Family level using microscopic and morphological methods.”
(THE BIRDSTRIKE IDENTIFICATION PROGRAM AT THE SMITHSONIAN INSTITUTION AND NEW RECOMMENDATIONS FOR DNA SAMPLING )
Hold on. Let’s say the Smithsonian did confirm Branta canadensis. The NTSB still has to demonstrate for the sake of scientific legitimacy that these feathers and fragments were ingested in Cactus 1549’s engines at 2800’, a defying of astronomical odds, and not scooped from the Hudson or salted, no pun intended, after the engines were shipped to Ohio.
It's Not Called 'Snarge' For Nothing
The CFM 56-5B has 36 individual fan disk blades direct driven by the low pressure turbine stage. At 100% N1 the fan blades rotate at approximately 5000rpm. That’s 83.33 revolutions per second and 0.012 second per revolution. A320’s climb at 90-95% N1 for a fan blade rotation range between 75-to-79.16 revolution per second.
Under normal climb N1, the 36 individual fan disk blades on each Cactus 1549 engine would complete a single revolution ranging from 0.0126-to-0.013 seconds.
In this 0.0126-to-0.013 second interval, Cactus 1549 climbing at 180kt forward velocity, will travel 3.69’-to-3.7’. The average length of a mature Canada Geese is 3.2’ or 38” long. Therefore, each of Cactus 1549’s fan blades would slice a goose into approximately 1.16” inch segments at 180kt. There will not be any 4” long Canada Goose feather hanging around after introduced to 36 individual CFM 56-5B fan disk blades moving forward in the air at 180kt and rotating 75-to-79 times per second.
That 4” Canada Geese feather sample in the labeled plastic bag did not wind up in that left engine at 2800’ over the Bronx or any other height. If was honestly extracted from that engine.
The Bird Cannon
To pass certification turbofan manufacturers fire every conceivable airborne object into a test engine that their fleet engines could ingest in any stage of flight. They have to be durable enough to take a beating. A multi cannon apparatus fires multiple dead birds wrapped in a plastic sabot weighing up to 8lb, twice the typical pass standard, from close range into the test engine spinning full honk, impacting the core and bypass in several different areas, to simulate multiple bird strike from takeoff roll to cruise to touchdown. The engine is subject to a Draconian litany of abuse to find out how much punishment the intended production line can survive. Sand, volcanic ash, hail, water, snow, ice and birds fired at nearly 450kt from close range. Each test is super high-speed filmed for super slow motion analysis. Not even at 450kt will a 4” goose feather that winds up traveling through the bypass, as on Cactus 1549’s NTSB sample, remain 4” after shredded by the fan disk and then flash barbecued by the exhaust. The engines must also pass the ‘blade off’ test. The housing must be strong enough to contain a titanium blade snapping off at maximum rpm, enough energy to toss a mid-size car 100’ in the air, from breaching the housing and penetrating the cabin or wing. No goose will ever dent, tear or deform any part of the bypass area or core itself. However, a snapped blade caused by bird strike can and will render visible damage in the form of circumferential scoring but only after the bird and its feathers are long gone except for blood smear as the only evidence that a bird was ingested. A bird strikes the fan disk at such velocity and momentum that the now sliced bits continue traveling straight on through the engine; not pushed laterally against the side walls.
The tagged NTSB feather sample is so phony it’s comical. US Airways and GE Aviation appear to be so desperate for people to believe that Cactus 1549 hit birds that either or both planted this feather and five other feather part samples. When the evidence is fake you can rest assured that the reasoning is just as contrived.
That feather looks too good to have passed through the super CuisineArt shredder of the GE 56-5B fan disk on Cactus 1549 and why bird strike remains are dubbed “snarge.” There’s nothing left other than blood spattering as the bird is ripped to shreds and ejected in the blink of an eye. That feather is in too good condition to come from a midair goose buffet 2800’ over the Bronx.
If Cactus 1549 really did ingest Canada Geese why only feathers recovered and no blood?
The NTSB's Magic Goose Feather Story
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
February 12, 2009
FOURTH UPDATE ON INVESTIGATION INTO DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009. The bird remains found in both engines of US Airways flight 1549 have been identified by the Smithsonian Institution's Feather Identification Laboratory as Canada Goose (Branta canadensis).
The lab made the identification for the NTSB through DNA analysis as well as through morphological comparisons in which feather fragments were compared with Canada Goose specimens in the museum's collections; the microscopic feather samples were compared with reference microslide collections.
A total of 25 samples of bird remains have been examined as of today. Additional analysis will be conducted on samples received from the NTSB to attempt to determine if the Canada Geese were resident or migratory. While no determination has been made about how many birds the aircraft struck or how many were ingested into the engines, an adult Canada Goose typically ranges in size from 5.8 to 10.7 pounds, however larger individual resident birds can exceed published records.
The accident aircraft was powered by two CFM56-5B/P turbofan engines. The bird ingestion standard in effect when this engine type was certified in 1996 included the requirement that the engine must withstand the ingestion of a four-pound bird without catching fire, without releasing hazardous fragments through the engine case, without generating loads high enough to potentially compromise aircraft structural components, or without losing the capability of being shut down. The certification standard does not require that the engine be able to continue to generate thrust after ingesting a bird four pounds or larger.
NTSB investigators worked closely with wildlife biologists from the United States Department of Agriculture, both at the scene of the accident in New York City and during the engine teardowns at the manufacturer's facility in Cincinnati, to extract all of the organic material that was identified today.
###
NTSB Media Contact: Peter Knudson
(202) 314-6100
peter.knudson@ntsb.gov
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
February 4, 2009
THIRD UPDATE ON INVESTIGATION INTO DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009.
The left (#1) engine, which was recovered from the Hudson River on January 23 and subsequently shipped to the manufacturer in Cincinnati where the NTSB is directing a teardown, was found to contain bird remains. The organic material found in the right (#2) engine has also been confirmed to be bird remains. The material from both engines has been sent to the Smithsonian Institution in Washington where the particular bird species will be identified.
As part of its investigation into this accident, the NTSB investigated an engine surge event that occurred in the right (#2) engine during a flight on January 13, two days prior to the accident. The engine recovered from the surge and the remainder of the flight was completed uneventfully. The NTSB determined that the surge was due to a faulty temperature sensor, which was replaced by maintenance personal following approved procedures. After the engine was examined with a boroscope and found to be undamaged and in good working order, the aircraft was returned to service.
On December 31, 2008, the Federal Aviation Administration (FAA) issued an Airworthiness Directive (AD) covering all CFM56-5B series turbofan engines, the same type that was on the accident aircraft. After examining the engine maintenance records and interviewing relevant personnel, the NTSB determined that all of the requirements of the AD were complied with prior to the accident flight.
During the accident flight, the flight data recorder revealed no anomalies or malfunctions in either engine up to the point where the captain reported a bird strike, after which there was an uncommanded loss of thrust in both engines.
Last week the aircraft was moved from the barge where it had been docked in Jersey City, NJ, to a secure salvage yard in Kearny, NJ, where it will remain throughout the NTSB investigation, which is expected to last 12-18 months.
###
NTSB Media Contact: Peter Knudson
(202) 314-6100
peter.knudson@ntsb.gov
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
January 24, 2009
SECOND UPDATE ON INVESTIGATION OF DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009.
The left engine, which had separated from the aircraft during the ditching, was recovered from the Hudson River on Friday afternoon, January 23, 2009. The initial external examination of the engine revealed dents on both the spinner and inlet lip of the engine cowling. Five booster inlet guide vanes are fractured and eight outlet guide vanes are missing. A visual examination of the engine did not reveal evidence of organic material; there was evidence of soft body impact damage.
Both of the engines will be boxed and shipped to the manufacturer in Cincinnati where NTSB investigators will oversee a complete tear-down of each engine. Advanced technology will be employed to detect any organic material not apparent during the initial visual examination.
Several NTSB investigators remain on-scene and are supervising Airbus technicians as the aircraft wreckage is prepared for long-term storage. This process includes removing the wings and the horizontal and vertical stabilizers. The aircraft wreckage will be shipped to a secure storage facility where it will remain available to the NTSB throughout the course of the investigation.
The NTSB wishes to acknowledge the support and cooperation of the numerous federal, state and local agencies that worked so closely with Safety Board investigators and were of great assistance throughout the entire on-scene phase of the investigation.
###
Media Contact: Peter Knudson
peter.knudson@ntsb.gov
NTSB Public Affairs: 202-314-6100
National Transportation Safety Board
Washington, DC 20594
February 12, 2009
FOURTH UPDATE ON INVESTIGATION INTO DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009. The bird remains found in both engines of US Airways flight 1549 have been identified by the Smithsonian Institution's Feather Identification Laboratory as Canada Goose (Branta canadensis).
The lab made the identification for the NTSB through DNA analysis as well as through morphological comparisons in which feather fragments were compared with Canada Goose specimens in the museum's collections; the microscopic feather samples were compared with reference microslide collections.
A total of 25 samples of bird remains have been examined as of today. Additional analysis will be conducted on samples received from the NTSB to attempt to determine if the Canada Geese were resident or migratory. While no determination has been made about how many birds the aircraft struck or how many were ingested into the engines, an adult Canada Goose typically ranges in size from 5.8 to 10.7 pounds, however larger individual resident birds can exceed published records.
The accident aircraft was powered by two CFM56-5B/P turbofan engines. The bird ingestion standard in effect when this engine type was certified in 1996 included the requirement that the engine must withstand the ingestion of a four-pound bird without catching fire, without releasing hazardous fragments through the engine case, without generating loads high enough to potentially compromise aircraft structural components, or without losing the capability of being shut down. The certification standard does not require that the engine be able to continue to generate thrust after ingesting a bird four pounds or larger.
NTSB investigators worked closely with wildlife biologists from the United States Department of Agriculture, both at the scene of the accident in New York City and during the engine teardowns at the manufacturer's facility in Cincinnati, to extract all of the organic material that was identified today.
###
NTSB Media Contact: Peter Knudson
(202) 314-6100
peter.knudson@ntsb.gov
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
February 4, 2009
THIRD UPDATE ON INVESTIGATION INTO DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009.
The left (#1) engine, which was recovered from the Hudson River on January 23 and subsequently shipped to the manufacturer in Cincinnati where the NTSB is directing a teardown, was found to contain bird remains. The organic material found in the right (#2) engine has also been confirmed to be bird remains. The material from both engines has been sent to the Smithsonian Institution in Washington where the particular bird species will be identified.
As part of its investigation into this accident, the NTSB investigated an engine surge event that occurred in the right (#2) engine during a flight on January 13, two days prior to the accident. The engine recovered from the surge and the remainder of the flight was completed uneventfully. The NTSB determined that the surge was due to a faulty temperature sensor, which was replaced by maintenance personal following approved procedures. After the engine was examined with a boroscope and found to be undamaged and in good working order, the aircraft was returned to service.
On December 31, 2008, the Federal Aviation Administration (FAA) issued an Airworthiness Directive (AD) covering all CFM56-5B series turbofan engines, the same type that was on the accident aircraft. After examining the engine maintenance records and interviewing relevant personnel, the NTSB determined that all of the requirements of the AD were complied with prior to the accident flight.
During the accident flight, the flight data recorder revealed no anomalies or malfunctions in either engine up to the point where the captain reported a bird strike, after which there was an uncommanded loss of thrust in both engines.
Last week the aircraft was moved from the barge where it had been docked in Jersey City, NJ, to a secure salvage yard in Kearny, NJ, where it will remain throughout the NTSB investigation, which is expected to last 12-18 months.
###
NTSB Media Contact: Peter Knudson
(202) 314-6100
peter.knudson@ntsb.gov
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
January 24, 2009
SECOND UPDATE ON INVESTIGATION OF DITCHING OF US AIRWAYS JETLINER INTO HUDSON RIVER
The following is an update on the National Transportation Safety Board's investigation of US Airways flight 1549, which ditched into the Hudson River on January 15, 2009.
The left engine, which had separated from the aircraft during the ditching, was recovered from the Hudson River on Friday afternoon, January 23, 2009. The initial external examination of the engine revealed dents on both the spinner and inlet lip of the engine cowling. Five booster inlet guide vanes are fractured and eight outlet guide vanes are missing. A visual examination of the engine did not reveal evidence of organic material; there was evidence of soft body impact damage.
Both of the engines will be boxed and shipped to the manufacturer in Cincinnati where NTSB investigators will oversee a complete tear-down of each engine. Advanced technology will be employed to detect any organic material not apparent during the initial visual examination.
Several NTSB investigators remain on-scene and are supervising Airbus technicians as the aircraft wreckage is prepared for long-term storage. This process includes removing the wings and the horizontal and vertical stabilizers. The aircraft wreckage will be shipped to a secure storage facility where it will remain available to the NTSB throughout the course of the investigation.
The NTSB wishes to acknowledge the support and cooperation of the numerous federal, state and local agencies that worked so closely with Safety Board investigators and were of great assistance throughout the entire on-scene phase of the investigation.
###
Media Contact: Peter Knudson
peter.knudson@ntsb.gov
NTSB Public Affairs: 202-314-6100
Friday, March 20, 2009
Cactus 1549
In 2007, a string of Airbus Industrie A320 worldwide operators reported compressor stalls by “highly deteriorated HPCs” in their GE 56-5B turbofans to GE Aviation (GEA), FAA and EASA. http://tinyurl.com/dayvv4 The same engines engines on Cactus 1549.
As the directive explains, GEA first reacted to the stall reports by devising engine software 5QB update to reduce the occurrence and severity of HPC deterioration on GE-powered A320s. Then the stall incidents, after the 5QB update, reoccurred. 5QB was a dud. So GEA issued a maintenance directive to all 56-5B-powered operators to ground test their units and replace any that produced EGT over 80 Celsius with a brand new 56-5B. This means GEA wasn’t able to find a workable fix besides full replacement of a used deteriorated random ticking time bomb with a new random bomb should EGT (safely parked on the ground with no such luxury in midair) exceed 80C. Nothing novel here, once a design is flawed it’s next to impossible to reengineer once in production. Then an Air France A320 with GE 56-5Bs compressor stalled out of Tunis in December and the European Aviation Safety Agency and GEA released an “Emergency Airworthiness Directive” (2008-0227-E) on Dec. 23, 2008. The original GEA directive, essentially, now EASA stamped with “Emergency” affixed.
So that there is no confusion, the GE 56-5B high pressure compressor was rendered “Emergency” by its own manufacturer.
The same Cactus 1549 aircraft with different crew double compressor stalled over Newark climbing up to cruise in January 13, 2009, two days prior to the Hudson regatta. http://www.nj.com/hudson/index.ssf/2009/01/flight_1549_had_engine_problem.html
1549’s HPCs that stalled over the Bronx were the same units that stalled over Newark. USAir didn’t replace these units, the only option by GEA’s terse emergency directive, both obviously and unmistakably deteriorated contrary to NTSB’s gibberish of dud temperature sensor (Sorry, NTSB, a bum sensor doesn’t go BANG with cabin electrical loss), with brand new 56-5Bs in the 72 hour layover. USAir put the plane and deteriorated HPCs back in service as is. Two days later 1549 took off from La Guardia, both engines stalled at 2800’ and the pilot glided down into the Hudson, and out waddled the bird story.
The GE 56-5B line and Cactus 1549’s service record 100% undermine the bird story. Leaving only the matter of deconstructing the extensively edited audio tapes plus transcripts, NTSB clown routine and media disinformation to explain how the fleece job was pulled off.
GE Aviation sequestered 1549’s engines as soon as detached and/or salvaged and shipped them back to its Ohio headquarters, concealing the culprit HPCs. Not long after, the alleged story of “Branta Canadensis” “feathers” recovered from 1549’s engines emerged, as if any feather would loiter after a 140-150nm extended rinse cycle in the Hudson already riddled with innumerable detached waterfowl feathers. USAir sequestered the two pilots in seclusion and imposed a media blackout. Then the spin doctors set to work transforming crew error which, if true that hit birds, would be monumental neglect, into “Hero pilot,” snubbing the flight attendants and ferry boat crews to focus on and idolize P-in-C, Chesley Sullenberger. Then the spin went from the sublime to the ridiculous with a toweled off Chesley taking a bow to great applause at the Superbowl. No doubt each Superbowl fan and viewer personally received and read the GEA/EASA emergency directive, fully cognizant of the 56-5B disastrous service record, 1549’s double compressor stall over Newark, and magically rejuvenated temperature sensor which just happens to be backed up to redundancy and would never shutdown the engine even if every temperature sensor failed.
As the directive explains, GEA first reacted to the stall reports by devising engine software 5QB update to reduce the occurrence and severity of HPC deterioration on GE-powered A320s. Then the stall incidents, after the 5QB update, reoccurred. 5QB was a dud. So GEA issued a maintenance directive to all 56-5B-powered operators to ground test their units and replace any that produced EGT over 80 Celsius with a brand new 56-5B. This means GEA wasn’t able to find a workable fix besides full replacement of a used deteriorated random ticking time bomb with a new random bomb should EGT (safely parked on the ground with no such luxury in midair) exceed 80C. Nothing novel here, once a design is flawed it’s next to impossible to reengineer once in production. Then an Air France A320 with GE 56-5Bs compressor stalled out of Tunis in December and the European Aviation Safety Agency and GEA released an “Emergency Airworthiness Directive” (2008-0227-E) on Dec. 23, 2008. The original GEA directive, essentially, now EASA stamped with “Emergency” affixed.
So that there is no confusion, the GE 56-5B high pressure compressor was rendered “Emergency” by its own manufacturer.
The same Cactus 1549 aircraft with different crew double compressor stalled over Newark climbing up to cruise in January 13, 2009, two days prior to the Hudson regatta. http://www.nj.com/hudson/index.ssf/2009/01/flight_1549_had_engine_problem.html
1549’s HPCs that stalled over the Bronx were the same units that stalled over Newark. USAir didn’t replace these units, the only option by GEA’s terse emergency directive, both obviously and unmistakably deteriorated contrary to NTSB’s gibberish of dud temperature sensor (Sorry, NTSB, a bum sensor doesn’t go BANG with cabin electrical loss), with brand new 56-5Bs in the 72 hour layover. USAir put the plane and deteriorated HPCs back in service as is. Two days later 1549 took off from La Guardia, both engines stalled at 2800’ and the pilot glided down into the Hudson, and out waddled the bird story.
The GE 56-5B line and Cactus 1549’s service record 100% undermine the bird story. Leaving only the matter of deconstructing the extensively edited audio tapes plus transcripts, NTSB clown routine and media disinformation to explain how the fleece job was pulled off.
GE Aviation sequestered 1549’s engines as soon as detached and/or salvaged and shipped them back to its Ohio headquarters, concealing the culprit HPCs. Not long after, the alleged story of “Branta Canadensis” “feathers” recovered from 1549’s engines emerged, as if any feather would loiter after a 140-150nm extended rinse cycle in the Hudson already riddled with innumerable detached waterfowl feathers. USAir sequestered the two pilots in seclusion and imposed a media blackout. Then the spin doctors set to work transforming crew error which, if true that hit birds, would be monumental neglect, into “Hero pilot,” snubbing the flight attendants and ferry boat crews to focus on and idolize P-in-C, Chesley Sullenberger. Then the spin went from the sublime to the ridiculous with a toweled off Chesley taking a bow to great applause at the Superbowl. No doubt each Superbowl fan and viewer personally received and read the GEA/EASA emergency directive, fully cognizant of the 56-5B disastrous service record, 1549’s double compressor stall over Newark, and magically rejuvenated temperature sensor which just happens to be backed up to redundancy and would never shutdown the engine even if every temperature sensor failed.
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