DH8D, vicinity Buffalo NY USA, 2009
DH8D, vicinity Buffalo NY USA, 2009
On 12 February 2009, a Bombardier DHC-8-400 on a night ILS approach to Buffalo-Niagara airport departed controlled flight and was completely destroyed by ground impact and subsequent fire. The Investigation found that the Captain had failed to effectively manage the flight and that his consequent response to a resulting stick shaker activation had been completely contrary to applicable procedures and his training, leading directly to the loss of the aircraft. The aircraft operator s normal approach procedures were also determined to be inadequate and it was noted that prior to the accident, sterile flight deck procedures had been comprehensively ignored.
On 12 February 2009, a Bombardier DHC-8-400 which was being operated by Colgan Air on a scheduled domestic passenger from Newark to Buffalo-Niagara under a Continental Airlines flight number as part of a codeshare agreement in place between the two operators was on an ILS approach to the destination runway in night VMC when control was lost and the aircraft crashed and burned in a residential area approximately 5 nm from the runway killing all occupants and one additional person on the ground.
The Investigation was carried out by the National Transportation Safety Board (USA) (NTSB). It established that 47 year-old Captain, who had been PF for the accident flight had a total of 3,379 flying hours of which just 111 hours had been on type. He had been employed by Colgan for a little over 3 years. The 24 year-old First Officer had a total of 2,240 flying hours which included 774 hours on type, the latter all achieved after she had joined Colgan about a year prior to the accident.
It was found that the aircraft had been fully serviceable and not subject to any significant effects` attributable to ice accretion at the time of the accident. However, reference airspeeds set by the flight crew for the approach were not compatible with the position of the “reference speeds switch” which was in the “increase” (icing conditions) position which would therefore automatically trigger a stall warning in the form of a stick shaker activation at a higher airspeed.
As a result, when a stick shaker activation occurred at about 6nm from touchdown, the aircraft was actually around 20 to 22 knots above a stall rather than the a 5 to 7 knots which this activation normally indicates. The activation was automatically accompanied by autopilot disconnection automatically and the PF responded with a power increase and an abrupt aft movement on the control column. This had the effect of increasing the angle of attack (AOA) from +8° to +13° with a pitch attitude of about +18° and led to airspeed reducing from 131 kt at the onset of the stall to 125 kt. The airflow over the wing separated as the stall AOA was exceeded and a wing drop occurred. The Report concludes, following this description of the beginning of loss of control, that:
“the Captain’s inappropriate aft control column inputs in response to the stick shaker caused the airplane’s wing to stall”
Three stick pusher activations then followed in rapid succession, beginning as AoA reached +18 degrees. The Captain’s response to each of these was a successively increasing rearward force on the control column - the precise opposite of the applicable SOPs for such an event. As a result, the opportunity to regain control of the aircraft was lost.
The investigation also found that the intensity of the post crash fire had been aggravated by release of gas from a domestic supply pipe damaged by the aircraft ground impact. these issues are addressed to the Federal Aviation Administration (FAA)."
A total of 46 formally-documented Findings from the Investigation included the following:
- 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
- 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 colour 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 failure of both pilots to detect this situation was the result of a significant breakdown in their monitoring responsibilities and workload management
- 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 recover
- No evidence indicated that the (aircraft type involved) was susceptible to a tailplane stall.
- The Captain’s failure to effectively manage the flight
- enabled conversation that delayed checklist completion and conflicted with sterile cockpit procedures and
- created an environment that impeded timely error detection.
- 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 behaviour.
- 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.
- 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 current air carrier approach-to-stall training did not fully prepare the flight crew for an unexpected stall in the (aircraft type involved) and did not address the actions that are needed to recover from a fully developed stall.
- 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 (aircraft type involved), resulting in negative training.
- The current Federal Aviation Administration surveillance standards for oversight at air carriers undergoing rapid growth and increased complexity of operations do not guarantee that any challenges encountered by the carriers as a result of these changes will be appropriately mitigated.
- Mandatory flight operational quality assurance programs would enhance flight safety because all operators would have readily available data to identify operational risks and use in developing corrective actions.
The NTSB determined that the Probable Cause of the 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".
Four Contributory Factors were also identified:
- the flight crew’s failure to monitor airspeed in relation to the rising position of the low speed cue,
- the flight crew’s failure to adhere to sterile cockpit procedures,
- the captain’s failure to effectively manage the flight, and
- Colgan Air’s inadequate procedures for airspeed selection and management during approaches in icing conditions."
A total of 24 new Safety Recommendations were made as a result of the Investigation as follows:
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to review their standard operating procedures to verify that they are consistent with the flight crew monitoring techniques described in Advisory Circular (AC) 120-71A, “Standard Operating Procedures for Flight Deck Crewmembers”; if the procedures are found not to be consistent, revise the procedures according to the AC guidance to promote effective monitoring.
- that the Federal Aviation Administration (FAA) require that airspeed indicator display systems on all aircraft certified under 14 Code of Federal Regulations Part 25 and equipped with electronic flight instrument systems depict a yellow/amber cautionary band above the low-speed cue or airspeed indicator digits that change from white to yellow/amber as the airspeed approaches the low-speed cue, consistent with Advisory Circular 25-11A, “Electronic Flight Displays.”
- that the Federal Aviation Administration (FAA) require, for all airplanes engaged in commercial operations under 14 Code of Federal Regulations Parts 121, 135, and 91K, the installation of low-airspeed alert systems that provide pilots with redundant aural and visual warnings of an impending hazardous low-speed condition.
- that the Federal Aviation Administration (FAA) issue an advisory circular with guidance on leadership training for upgrading captains at 14 Code of Federal Regulations Part 121, 135, and 91K operators, including methods and techniques for effective leadership; professional standards of conduct; strategies for briefing and debriefing; reinforcement and correction skills; and other knowledge, skills, and abilities that are critical for air carrier operations. [A-10-13]
- that the Federal Aviation Administration (FAA) require all 14 Code of Federal Regulations Part 121, 135, and 91K operators to provide a specific course on leadership training to their upgrading captains that is consistent with the advisory circular requested in Safety Recommendation A-10-13.
- that the Federal Aviation Administration (FAA) develop, and distribute to all pilots, multimedia guidance materials on professionalism in aircraft operations that contain standards of performance for professionalism; best practices for sterile cockpit adherence; techniques for assessing and correcting pilot deviations; examples and scenarios; and a detailed review of accidents involving breakdowns in sterile cockpit and other procedures, including this accident. Obtain the input of operators and air carrier and general aviation pilot groups in the development and distribution of these guidance materials.
- that the Federal Aviation Administration (FAA) require all 14 Code of Federal Regulations Part 121, 135, and 91K operators to address fatigue risks associated with commuting, including identifying pilots who commute, establishing policy and guidance to mitigate fatigue risks for commuting pilots, using scheduling practices to minimize opportunities for fatigue in commuting pilots, and developing or identifying rest facilities for commuting pilots.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to document and retain electronic and/or paper records of pilot training and checking events in sufficient detail so that the carrier and its principal operations inspector can fully assess a pilot’s entire training performance.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to include the training records requested in Safety Recommendation A-10-17 as part of the remedial training program requested in Safety Recommendation A-05-14.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to provide the training records requested in Safety Recommendation A-10-17 to hiring employers to fulfill their requirement under the Pilot Records Improvement Act.
- that the Federal Aviation Administration (FAA) develop a process for verifying, validating, auditing, and amending pilot training records at 14 Code of Federal Regulations Part 121, 135, and 91K operators to guarantee the accuracy and completeness of the records.
- that the Federal Aviation Administration (FAA) direct 14 Code of Federal Regulations Part 121, 135, and 91K operators of airplanes equipped with a reference speeds switch or similar device to:
- develop procedures to establish that, during approach and landing, airspeed reference bugs are always matched to the position of the switch and
- implement specific training to ensure that pilots demonstrate proficiency in this area.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators and 14 Code of Federal Regulations Part 142 training centres to develop and conduct training that incorporates stalls that are fully developed; are unexpected; involve autopilot disengagement; and include airplane-specific features, such as a reference speeds switch.
- that the Federal Aviation Administration (FAA) require all 14 Code of Federal Regulations Part 121, 135, and 91K operators of stick pusher-equipped aircraft to provide their pilots with pusher familiarisation simulator training.
- that the Federal Aviation Administration (FAA) define and codify minimum simulator model fidelity requirements to support an expanded set of stall recovery training requirements, including recovery from stalls that are fully developed. These simulator fidelity requirements should address areas such as required angle-of-attack and sideslip angle ranges, motion cueing, proof-of-match with post-stall flight test data, and warnings to indicate when the simulator flight envelope has been exceeded.
- that the Federal Aviation Administration (FAA) identify which airplanes operated under 14 Code of Federal Regulations Part 121, 135, and 91K are susceptible to tailplane stalls and then:
- require operators of those airplanes to provide an appropriate aircraft-specific tailplane stall recovery procedure in their training manuals and company procedures and
- direct operators of those airplanes that are not susceptible to tailplane stalls to ensure that training and company guidance for the airplanes explicitly states this lack of susceptibility and contains no references to tailplane stall recovery procedures.
- that the Federal Aviation Administration (FAA) develop more stringent standards for surveillance of 14 Code of Federal Regulations (CFR) Part 121 135, and 91K operators that are experiencing rapid growth, increased complexity of operations, accidents and/or incidents, or other changes that warrant increased oversight, including the following:
- verify that inspector staffing is adequate to accomplish the enhanced surveillance that is promulgated by the new standards,
- increase staffing for those certificates with insufficient staffing levels, and
- augment the inspector staff with available and airplane-type-qualified inspectors from all Federal Aviation Administration regions and 14 CFR Part 142 training centres to provide quality assurance over the operators’ aircrew program designee workforce.
- that the Federal Aviation Administration (FAA) require all 14 Code of Federal Regulations Part 121, 135, and 91K operators to:
- develop and implement flight operational quality assurance programs that collect objective flight data, #analyse these data and implement corrective actions to identified systems safety issues, and
- share the deidentified aggregate data generated through these analyses with other interested parties in the aviation industry through appropriate means.
- that the Federal Aviation Administration (FAA) seek specific statutory and/or regulatory authority to protect data that operators share with the Federal Aviation Administration as part of any flight operational quality assurance program. [A-10-28]
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to:
- routinely download and analyse all available sources of safety information, as part of their flight operational quality assurance program, to identify deviations from established norms and procedures;
- provide appropriate protections to ensure the confidentiality of the deidentified aggregate data; and
- ensure that this information is used for safety-related and not punitive purposes.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to incorporate explicit guidance to pilots, including checklist reminders as appropriate, prohibiting the use of personal portable electronic devices on the flight deck.
- that the Federal Aviation Administration (FAA) implement a process to document that all 14 Code of Federal Regulations Part 121, 135, and 91K operators have taken appropriate action in response to safety-critical information transmitted through the safety alert for operators process or another method.
- that the Federal Aviation Administration (FAA) require 14 Code of Federal Regulations Part 121, 135, and 91K operators to revise the methodology for programming their adverse weather phenomena reporting and forecasting subsystems so that the subsystem-generated weather document for each flight contains all pertinent weather information, including Airmen’s Meteorological Information, Significant Meteorological Information, and other National Weather Service in-flight weather advisories, and omits weather information that is no longer valid.
- that the Federal Aviation Administration (FAA) require (their) Principal Operations Inspectors (for)14 Code of Federal Regulations Part 121, 135, and 91K operators to periodically review the weather documents generated for their carriers to verify that those documents are consistent with the information requested in Safety Recommendation A-10-32.
- that the Federal Aviation Administration (FAA) update the definitions for reportable icing intensities in the Aeronautical Information Manual so that the definitions are consistent with the more detailed intensities defined in Advisory Circular 91-74A, “Pilot Guide: Flight in Icing Conditions.” [A-10-34]
Three previously issued Safety Recommendations to the FAA were also re-iterated.
The 299-page Final Report of the Investigation was adopted by the National Transportation Safety Board (NTSB) on 2 February 2010 and subsequently published.