Wednesday, February 03, 2010

Highlights of the NTSB's findings on the Colgan Air accident near Buffalo in February 2009

by B. N. Sullivan

NTSB logoYesterday the U.S. National Transportation Safety Board (NTSB) released a summary of its findings regarding the February, 2009 crash of a Colgan Air Bombardier DHC-8-400 near Buffalo, NY. The title of the press release that announced the findings read (in capital letters), CAPTAIN’S INAPPROPRIATE ACTIONS LED TO CRASH OF FLIGHT 3407 IN CLARENCE CENTER, NEW YORK, NTSB SAYS. Talk about cutting to the chase, right in the title!

Yesterday's report elaborated on the stark title of the press release, with this statement of probable cause:
The National Transportation Safety Board determines that the probable cause of this accident was the captain’s inappropriate response to the activation of the stick shaker, which led to an aerodynamic stall from which the airplane did not recover.
Contributing to the accident were (1) the flight crew’s failure to monitor airspeed in relation to the rising position of the low-speed cue, (2) the flight crew’s failure to adhere to sterile cockpit procedures, (3) the captain’s failure to effectively manage the flight, and (4) Colgan Air’s inadequate procedures for airspeed selection and management during approaches in icing conditions.
The NTSB summary included a list of 46 individual conclusions. Among the findings:
  • The recovered components showed no evidence of any preimpact structural, engine, or system failures, including no indications of any problems with the airplane’s ice protection system.
  • The air traffic controllers who were responsible for the flight during its approach to Buffalo-Niagara International Airport performed their duties properly and responded immediately and appropriately to the loss of radio and radar contact with the flight.
  • This accident was not survivable.
  • The captain’s inappropriate aft control column inputs in response to the stick shaker caused the airplane’s wing to stall.
  • The minimal aircraft performance degradation resulting from ice accumulation did not affect the flight crew’s ability to fly and control the airplane.
So, no support for those who theorized that icing was the cause of the accident. Instead, the NTSB seems to be saying that pilot error, independent of weather conditions, led to the tragic outcome.

Here's more:
  • Explicit cues associated with the impending stick shaker onset, including the decreasing margin between indicated airspeed and the low-speed cue, the airspeed trend vector pointing downward into the low-speed cue, the changing color of the numbers on the airplane’s indicated airspeed display, and the airplane’s excessive nose-up pitch attitude, were presented on the flight instruments with adequate time for the pilots to initiate corrective action, but neither pilot responded to the presence of these cues.
  • The reason the captain did not recognize the impending onset of the stick shaker could not be determined from the available evidence, but the first officer’s tasks at the time the low-speed cue was visible would have likely reduced opportunities for her timely recognition of the impending event; the failure of both pilots to detect this situation was the result of a significant breakdown in their monitoring responsibilities and workload management.
  • The flight crew did not consider the position of the reference speeds switch when the stick shaker activated.
  • The captain’s response to stick shaker activation should have been automatic, but his improper flight control inputs were inconsistent with his training and were instead consistent with startle and confusion.
  • The captain did not recognize the stick pusher’s action to decrease angle-of-attack as a proper step in a stall recovery, and his improper flight control inputs to override the stick pusher exacerbated the situation.
  • It is unlikely that the captain was deliberately attempting to perform a tailplane stall recovery.
  • No evidence indicated that the Q400 was susceptible to a tailplane stall.
  • Although the reasons the first officer retracted the flaps and suggested raising the gear could not be determined from the available information, these actions were inconsistent with company stall recovery procedures and training.
  • The Q400 airspeed indicator lacked low-speed awareness features, such as an amber band above the low-speed cue or airspeed indications that changed to amber as speed decrease toward the low-speed cue, that would have facilitated the flight crew’s detection of the developing low-speed situation.
  • An aural warning in advance of the stick shaker would have provided a redundant cue of the visual indication of the rising low-speed cue and might have elicited a timely response from the pilots before the onset of the stick shaker.
  • The captain’s failure to effectively manage the flight (1) enabled conversation that delayed checklist completion and conflicted with sterile cockpit procedures and (2) created an environment that impeded timely error detection.
These findings are uniformly damning of the captain and, to a lesser extent, the first officer. But then the NTSB report broadens the focus of responsibility to include Colgan Air, the pilots' employer:
  • The monitoring errors made by the accident flight crew demonstrate the continuing need for specific pilot training on active monitoring skills.
  • Colgan Air’s standard operating procedures at the time of the accident did not promote effective monitoring behavior.
  • Specific leadership training for upgrading captains would help standardize and reinforce the critical command authority skills needed by a pilot-in-command during air carrier operations.
  • Because of the continuing number of accidents involving a breakdown of sterile cockpit discipline, collaborative action by the Federal Aviation Administration and the aviation industry to promptly address this issue is warranted.
  • The flight crewmembers’ performance during the flight, including the captain’s deviations from standard operating procedures and the first officer’s failure to challenge these deviations, was not consistent with the crew resource management (CRM) training that they had received or the concepts in the Federal Aviation Administration’s CRM guidance.
Next, issues related to the role played by pilot fatigue and possible illness are addressed:
  • The pilots’ performance was likely impaired because of fatigue, but the extent of their impairment and the degree to which it contributed to the performance deficiencies that occurred during the flight cannot be conclusively determined.
  • All pilots, including those who commute to their home base of operations, have a personal responsibility to wisely manage their off-duty time and effectively use available rest periods so that they can arrive for work fit for duty; the accident pilots did not do so by using an inappropriate facility during their last rest period before the accident flight.
  • Colgan Air did not proactively address the pilot fatigue hazards associated with operations at a predominantly commuter base.
  • Operators have a responsibility to identify risks associated with commuting, implement strategies to mitigate these risks, and ensure that their commuting pilots are fit for duty.
  • The first officer’s illness symptoms did not likely affect her performance directly during the flight.
A number of the NTSB's findings addressed pilot qualificactions and training deficiencies:
  • The captain had not established a good foundation of attitude instrument flying skills early in his career, and his continued weaknesses in basic aircraft control and instrument flying were not identified and adequately addressed.
  • Remedial training and additional oversight for pilots with training deficiencies and failures would help ensure that the pilots have mastered the necessary skills for safe flight.
  • Colgan Air’s electronic pilot training records did not contain sufficient detail for the company or its principal operations inspector to properly analyze the captain’s trend of unsatisfactory performance.
  • Notices of disapproval need to be considered along with other available information about pilot applicants so that air carriers can fully identify those pilots who have a history of unsatisfactory performance.
  • Colgan Air did not use all available sources of information on the flight crew’s qualifications and previous performance to determine the crew’s suitability for work at the company.
  • Colgan Air’s procedures and training at the time of the accident did not specifically require flight crews to cross-check the approach speed bug settings in relation to the reference speeds switch position; such awareness is important because a mismatch between the bugs and the switch could lead to an early stall warning.
  • The current air carrier approach-to-stall training did not fully prepare the flight crew for an unexpected stall in the Q400 and did not address the actions that are needed to recover from a fully developed stall.
  • The circumstances of this and other accidents in which pilots have responded incorrectly to the stick pusher demonstrate the continuing need to train pilots on the actions of the stick pusher and the airplane’s initial response to the pusher.
  • Pilots could have a better understanding of an airplane’s flight characteristics during the post-stall flight regime if realistic, fully developed stall models were incorporated into simulators that are approved for such training.
  • The inclusion of the National Aeronautics and Space Administration icing video in Colgan Air’s winter operations training may lead pilots to assume that a tailplane stall might be possible in the Q400, resulting in negative training.
The remaining findings address systemic oversight issues; flight operational quality assurance (FOQA) programs; personal portable electronic devices on the flight deck; the use of safety alerts for operators (SAFOs), and weather data, including information related to icing.

The NTSB summary also includes 25 new recommendations to the Federal Aviation Administration (FAA).

Here is the link to the synopsis of the NTSB report, where you can read all of the findings and safety recommendations arising from the investigation of the Colgan Air Flight 3407 accident: NTSB/AAR-10-01: Summary of Findings

The full final report will be released later this month. When that happens, I will post the link here on Aircrew Buzz.

UPDATE Feb. 25, 2010: The complete final report on the Colgan Air Flight 3407 accident has been released. It is available for download from the NTSB Web site. Here is the link: NTSB Air Accident Report 1001 - 299-page 'pdf' file

RELATED: Click here to view all posts about  Colgan Air Flt 3407 on Aircrew Buzz.

7 comments:

  1. The whole official version of what happened is simply not credible. An experienced pilot does not respond to a stall indicator warning by pulling up on the nose at an angle of attack far in excess of even a takeoff climb. Uh uh, something else happened aboard that airplane.
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  2. In Colgan's submission to the NTSB, Colgan describes its hiring process as rigorous. But, Colgan said, Renslow "was not truthful on his employment application.
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  3. I live in Buffalo and actually flew in from Florida hours before 3407 did and there were ice conditions outside but nothing special for us here in Buffalo. I have some aviation experience and have followed the investigation of this crash. Some pilots on other forums made good reference to a n.a.s.a. video about tailplane stalls in which the stalled tailplane forces the stick DOWN and to recover the pilot must pull the stick back and reduce power. I originally thought Capt. Renslow interpreted the stick pusher to be a tail stall even though the dash 8 doesn't seem to be to prone to that. He may have thought it was a tail stall and guessed wrong. Like starviego I can't believe he would react to a wing stall by pulling the stick back. Although this is what the N.T.S.B. seems to imply. The N.T.S.B. report also specifically discounts the possibility the pilot interpreted it as a tail stall as posted in line 13 Quote:"It is unlikely that the captain was deliberately attempting to perform a tailplane stall recovery." in contradiction they also state in line 38 of the report quote: "The inclusion of the National Aeronautics and Space Administration icing video in Colgan Air’s winter operations training may lead pilots to assume that a tailplane stall might be possible in the Q400, resulting in negative training." Although the pilot was probably aware of possible icing I now believe the probable cause was caused by the auto pilot suddenly disengaging as it tried to maintain altitude at low throtle and a possible dirty airframe,followed almost immediately by the activation of stick shaker,than stick pusher and the pilots immediate reaction of full power which invariably pitched the nose up severly. He must have completely lost S.A. long enough so that his actions doomed the flight. Interestingly The N.T.S.B. report mentions little of the pilots reliance on auto pilot when they were at a point in their flight where he should have been flying with the seat of his pants.
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  4. There is a lot of interest in the attempted stall recovery. Not me, I'm most interested in twenty seconds during which the pilot(s) allow the airplane to coast along in level flight at only 2280ft with the power at idle while gear down, condition levers to high (flat pitch) is selected. This aircraft configuration causes the airplane to slow down rapidly 50 kts. All this time the power remains at idle. Power is increased only after the stall warning comes on.

    Did the crew think they were on some auto throttle approch mode or what, or did the pilot have micro sleep while flying? BTW a second captain was in the cockpits jump seat it said on the NTSB video. So all three (3) pilots seem to have had a lapse of their basic flying skills and didn't respond to the airspeed getting too slow. Twenty seconds is a long, long time during a landing approch to not
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  5. Reference the following contained in the NTSB report as causes for the crash:
    The captain’s response to stick shaker activation should have been automatic, but his improper flight control inputs were inconsistent with his training and were instead consistent with startle and confusion.
    Note:The FAA POI approved Colgans training syllabus for this aircraft. Both Colgan and the
    FAA were aware that the manufacturer of this aircraft did not include any reference to tail icing nor were there ever any warnings published by the manufacturer with regard to tail icing.
    The mere fact that most career pilots have NEVER been trained for Tail Icing and Tail Stall Recovery which has historically been the Astroid of unlikely possibilites on commercial aircraft, the mere introduction of the Colgan training video and fatigue was more likey a huge catalyst for the Captains justifiable paranoia concerning icing weather and "reflex training responses" while in icing conditions that day.
    The NTSB was obviously biased in every respect by listing the actions and inactions of the crew as the primary reason for the accident.
    I have researched and challanged NTSB reports in the past and successfully overturned the Media reported conclusions based on additional research beyond that of the FAA and NTSB who are both understaffed and historically Pilot assasins. The FAA is also more inclined not to include the manufacturer in the fault chain due to the ramifications and their liability in the initial certification process and approval.
    My contention as a life long airline pilot and former ASI is that Captain Renslow was following the tail stall recovery procedures to the best of his recollection from training video without approved aircraft simulator reinforcement which even though would have been inappropriate training for this type aircraft, may have prevented this mal training based accident.
    ReplyDelete
  6. nj.com/news/investigators_gather_wreckage.html
    ''initial reports said the plane was held up due to [u]mechanical problems[/u]''


    The MSM had fingered fatigue as the main culprit that caused the pilot error.  But there is NO direct evidence that fatigue had [b]anything[/b] to do with it.  Did the MSM tell you what the witnesses on the ground heard?



    NTSB Dockets, File 431227--witness statements

    pg2 of 131
    Vicki Braun
    ...plane engine had ''echo sound'' then sounded like the engine stopped then heard a ''boom.''

    pg6 of 131
    Shannon Alessandra
    Just prior to the airplane crashing, the engines made a ''weird sound.''

    pg7 of 131
    Jean Andreassen
    Andreassen stated that she heard strange noises from the engines

    pg8 of 131
    Kristen and Aaron Archambeault
    They both described the engine noise as ''sputtering''

    pg11 of 131
    Michele Beiter
    Michele stated the noise 'skipped' and she was relieved it stopped, and then it started again. Michel is positive there was a skip. Michele further described everthing she heard as, 'Noise, skip, noise, loud noise.'

    pg13 of 131
    Robert Bijak
    The engines sounded like a metallic rattle and remined Bijak of a car engine with no oil in it.

    pg14 of 131
    Tin Bojarski
    The plane did not sound right and sort of sounded like a car with a broken muffler.

    pg17 of 131
    Ronald Braunscheidel
    ...he heard a very loud spitting and sputtering sound of a plane engine flying overhead. Braunscheidel described the noise as a car without a muffler.

    pg 18 of 131
    Sharon Brennan
    Brennan believed the plane was... maybe in trouble based on the noise.

    pg28 of 131
    Dan Cizdziel
    ...heard a sputtering, binging noise....
    ReplyDelete
  7. pg42 of 131
    Doug Errick
    Errick indicated that as the plane got closer the engines became very rough. Errick thought the engines were coming on and off, almost like engines were trying to come back on, but couldn't remain running. Errick thought the engines were changing RPMs rapidly.

    pg49 of 131
    Mary Grefrath
    Grefrath recalled that the engine sounded like it was spuddering.

    pg66 of 131
    Jean Larocque
    Larocque... stated he heard puttering plane... Larocque reported that the engines were not making a uniform sound.

    pg 77 of 131
    Molly Merlo
    ...she heard the airplane make a ''gurgling'' sound.

    pg81 of 131
    Marianne Neri
    The engine noise did not sound like a normal plane, but more like a helicopter. It was obvious something was wrong with the engines.

    pg85 of 131
    Angela Pillo
    The sound was very loud and ''rough,'' as if the engine was having trouble. The sound was further described as sounding like a ''lawn mower''

    pg91 of 131
    Lisa Rott
    ....she heard a consistent low grumbling sound that she believed to be a propeller plane. Rott advised that the sound the plane's engines was not smooth and did not sound like other propeller planes that she has heard in the past.

    pg96 of 131
    Kenneth Smith
    ...heard a big bang then continued to hear the sound of airplane engines.

    pg89 of 131
    Joseph Summers
    ...heard a plane which was very low and didn't sound normal. Mr. Summers cited a ''rambling noise'' which sounded as if an engine was not running properly.

    pg101 of 131
    Rick Telfair
    Telfair stated he then heard a winding or grinding noise, then a screeching or grinding noise and approximately 20-30 seconds later heard a large boom... Telfair further described the noise of the engine as fighting, almost as though they were trying to go faster but couldn't, not accelerating but distressed.

    pg 102 of 131
    Denise Trabucco
    Trabucco described the sound as a humming, similar to a transformer prior to it blowing. Aafter the humming, Trabucco heard a popping sound. ... About a minute after the humming and popping sound, Trabucco and her family felt a vibration that felt a little like an earthquake.

    pg105 of 131
    Lorraine Unverzart
    The airplane engines made a ''chugging'' sound, similar to a ''spark plug misfiring.''

    pg106 of 131
    Louis Vitello
    ...he heard the plane engines sputtering as it approached, and then heard a ''popping sound.'' Immediately after that Mr. Vitello heard ''grinding'' noised, stating that the noises reminded him of gears grinding together, sounding like the gears were missing teeth.

    pg124 of 131
    David Wolf
    ...the engines were making an unusual ''shuttering'' sound

    pg126 of 131
    Melissa Wols
    She stated she heard the plane.... grinding and sputtering as it approached and passed over his residence. Wols advised it sounded similar to what grinding metal would sound like.

    pg129 of 131
    Rita Zirnheld
    It ''sounded like spttering'' and ''engine was coughing.''

    pg130 of 131
    Barbara Garrett
    She said the plane engine was making loud noises, as though metal was banging and clattering.
    ReplyDelete

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