“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.
