NATIONAL TRANSPORTATION SAFETY BOARD
Public Meeting of April 7, 2009
(Information subject to editing)

In-Flight Left Engine Fire
American Airlines Flight 1400
McDonnell Douglas DC-9-82, N454AA
St. Louis, Missouri
September 28, 2007
NTSB/AAR-09/03

This is a synopsis from the Safety Board’s report and does not include the Board’s rationale for the conclusions, probable cause, and safety recommendations.  Safety Board staff is currently making final revisions to the report from which the attached conclusions and safety recommendations have been extracted.  The final report and pertinent safety recommendation letters will be distributed to recommendation recipients as soon as possible.  The attached information is subject to further review and editing.

EXECUTIVE SUMMARY

On September 28, 2007, about 1313 central daylight time, American Airlines flight 1400, a McDonnell Douglas DC‑9‑82, N454AA, experienced an in‑flight engine fire during departure climb from Lambert‑St. Louis International Airport, St. Louis, Missouri. During the return to STL, the nose landing gear failed to extend, and the flight crew executed a go‑around, during which the crew extended the nose gear using the emergency procedure. The flight crew conducted an emergency landing, and the 2 flight crewmembers, 3 flight attendants, and 138 passengers deplaned on the runway. No occupant injuries were reported, but the airplane sustained substantial damage due to the fire. The scheduled passenger flight was operating under the provisions of the 14 Code of Federal Regulations Part 121 on an instrument flight rules flight plan. Visual meteorological conditions prevailed at the time of the accident. 

CONCLUSIONS

1. The flight crewmembers were properly certificated and qualified under Federal regulations. No evidence indicated any preexisting medical or physical condition that might have adversely affected the first officer’s performance during the accident flight. Although the captain had sleep apnea, the condition was being effectively treated, and no evidence indicated that the condition affected his performance during the accident flight. There was no evidence of flight crew fatigue.
2. The accident airplane was properly certificated and was equipped and dispatched in accordance with industry practices. The weight and balance of the airplane were within prescribed limits for takeoff.
3. Air traffic control did not facilitate the use of a designated emergency radio frequency, and neither aircraft rescue and firefighting (ARFF) personnel nor the pilots requested one; no evidence indicated that this impeded ARFF efforts.
4. American Airlines’ maintenance personnel did not clean the accident air turbine starter valve‑air filter in accordance with its C check cleaning procedures and, therefore, missed an opportunity to identify and replace the damaged filter.
5. The filter element of the air turbine starter valve-air filter disintegrated, allowing the end cap to become free, which blocked the air flow and caused the engine no-start condition.
6. American Airlines’ maintenance personnel’s troubleshooting efforts for the engine no-start condition incorrectly focused on the air turbine starter valve (ATSV) and engine start system wiring because of the intermittent nature of the condition, the history of ATSV electrical circuit problems, and the lack of a history of ATSV-air filter failures for which no troubleshooting guidance existed.
7. American Airlines’ maintenance personnel repeatedly used an unapproved maintenance procedure, which included using a prying device to push the air turbine starter valve manual override button, to manually start the accident engine, which resulted in bending the internal pin in the override button.
8. The internal pin in the left engine air turbine starter valve (ATSV) override button was bent, which resulted in the uncommanded opening of the ATSV during high‑power engine conditions at the beginning of the takeoff roll and caused the air turbine starter to freewheel until it sustained a catastrophic internal failure.
9. The open air turbine starter valve and resulting failed air turbine starter allowed a hotter than typical airstream and/or incandescent particles to flow into the engine nacelle area and likely provided the ignition source for the in‑flight fire.
10. A combustible fluid, such as oil, hydraulic fluid, or fuel, was available in the engine; however, fire damage precluded the determination of the specific source of the combustible fluid.
11. The pilots might not have immediately detected the air turbine starter valve (ATSV)-Open light illumination because of its location, static appearance, and color, and, once they detected the light, the pilots did not immediately respond to it because an open ATSV was considered an abnormal situation that did not require immediate action and they were involved in air traffic control communications and airplane configuration changes.
12. Coupling the air turbine starter valve (ATSV)‑Open light with the Master Caution system might increase pilots’ ability to detect the presence of an abnormal ATSV condition; however, unintended consequences, such as aborted takeoffs, may occur and more work needs to be done to determine whether the Federal Aviation Administration should mandate the modification of the ATSV‑Open light in the MD‑80 fleet.
13. The pilots failed to properly allocate tasks, including checklist execution and radio communications, and they did not effectively manage their workload, which adversely affected their ability to conduct essential cockpit tasks, such as completing appropriate checklists.
14. No preexisting indicators in the pilots’ training or performance histories were found that could explain their poor performance during the accident flight.
15. The pilots’ interruption of the emergency Engine Fire/Damage/Separation checklist at a critical point prolonged the fire and led to additional problems, including the loss of hydraulic pressure, which caused the nose landing gear to fail to extend.
16. Given the airplane’s altitude and the lack of time to prepare for a nose landing gear up landing, the captain’s decision to go around was a reasonable choice.
17. The captain’s decision not to conduct an emergency evacuation after the airplane landed was in accordance with company guidance and was appropriate because the fire was not severe and aircraft rescue and firefighting personnel were actively responding to the residual fire.
18. The Safety Board concludes that the incident commander’s decision to deplane the passengers after fuel spilled out of the engine area was prudent.
19. The first officer did not have a clear understanding of the relationship between the pneumatic crossfeed handle and the engine fire handle, most likely because of inadequate company guidance and training on the issue, which resulted in the first officer inadvertently reintroducing fuel to the left engine, creating potential unnecessary risk of fire.
20. Improved pilot training methods for responding to multiple systems failures, competing task demands, and increased workload would help pilots develop the skills and decision‑making abilities needed during both single and multiple abnormal and emergency situations.
21.  The casual atmosphere in the cockpit before takeoff affected and set a precedent for the pilots’ responses to the situations in flight and after landing, eroded the margins of safety provided by the standard operating procedures and checklists, and increased the risk to passengers and crew.
22. Operational procedures requiring that an airplane be configured for an evacuation when it is stopped away from the gate after a significant event would help expedite an emergency evacuation if one became necessary.
23. During the emergency situation, the flight attendants did not relay potentially pertinent information to the captain in accordance with company guidance and training.
24. Boeing and PTI inspection criteria for the air turbine starter valve (ATSV)‑air filter are inadequate to detect early‑stage fatigue fractures of the outer mesh of the filter element, and, because of the ATSV-air filter design, the inner mesh of the filter element cannot be inspected for evidence of fatigue.
25. American Airlines’ maintenance personnel were using maintenance procedures that were not in accordance with written manuals and guidelines, and its Continuing Analysis and Surveillance System program did not adequately detect and correct these performance deficiencies before they contributed to an accident.

 PROBABLE CAUSE

The National Transportation Safety Board determines that the probable cause of this accident was American Airlines’ maintenance personnel’s use of an inappropriate manual engine‑start procedure, which led to the uncommanded opening of the left engine air turbine starter valve, and a subsequent left engine fire, which was prolonged by the flight crew’s interruption of an emergency checklist to perform nonessential tasks. Contributing to the accident were deficiencies in American Airlines’ Continuing Analysis and Surveillance System program.

RECOMMENDATIONS TO THE FEDERAL AVIATION ADMINISTRATION

1. Evaluate the history of uncommanded air turbine starter valve (ATSV) open events in the MD‑80 fleet and the effectiveness of coupling the light to the Master Caution system to determine whether all MD‑80 airplanes need to be modified to couple the ATSV‑Open light to the Master Caution system. Once the evaluation is completed, require any necessary modifications.
2. Require principal operations inspectors to review their operators’ pilot guidance and training on task allocation and workload management during emergency situations to verify that they state that, to the extent practicable, the pilot running the checklists should not engage in nonessential operational tasks, such as radio communications.
3. Require MD‑80 series airplane operators to incorporate information about the relationship between the pneumatic crossfeed valve and the engine fire handle into their training programs and written guidance.
4. Establish best practices for conducting both single and multiple emergency and abnormal situations training.
5. Once the best practices for both single and multipleemergency and abnormal situations training asked for in Safety Recommendation [4] have been established, require that these best practices be incorporated into all operators’ approved training programs.
6. Require that operators provide pilots with guidance requiring that pilots and flight attendants actively monitor exit availability and configure the airplane and cabin for an evacuation when the airplane is stopped away from the gate after a significant event to help expedite an emergency evacuation if one becomes necessary.
7. Revise Advisory Circular 120‑48, “Communication and Coordination Between Flight Crewmembers and Flight Attendants,” to update guidance and training provided to flight and cabin crews regarding communications during emergency and unusual situations to reflect current industry knowledge based on research and lessons learned from relevant accidents and incidents over the last 20 years.
8. Require Boeing to establish an appropriate replacement interval for air turbine starter valve‑air filters installed on all MD‑80 series aircraft.

RECOMMENDATIONS TO AMERICAN AIRLINES

9. Evaluate your Continuing Analysis and Surveillance System program to determine why it failed to (1) identify deficiencies in its maintenance program associated with the MD‑80 engine no‑start failure and (2) discover the lack of compliance with company procedures. Then, make necessary modifications to the program to correct these shortcomings.

Related Press Release: http://ntsb.gov/Pressrel/2009/090407.html