Racing The Storm
On 01 June 1999 American Airlines Flight 1420 from Dallas Fort Worth to Little Rock Arkansas crashed after it overran its landing. The aircraft was a McDonnell Douglas DC-9-82 (MD-82). The crash resulted in the aircraft captain and ten passengers losing their lives, the first officer, flight attendants and 105 passengers receiving serious injuries and 24 passengers escaping without injury. The NTSB report stated the following as probable causes for the accident:
The flight crew's failure to discontinue the approach when severe thunderstorms and their associated hazards to flight operations had moved into the airport area and the crew's failure to ensure that the spoilers had extended after touchdown. (NTSB Identification Number: DCA99MA060)
Cognitive Failure
The crew's decision to continue in the face of deteriorating weather was a critical human factor. This plan continuation bias or 'get-there-itis' showed itself at multiple stages throughout the flight where the crew were given information that should have required a change in plan, which unfortunately didn't happen. Despite overwhelming information to discontinue the crew continued. Not only did the crew continue with the plan, there was no discussion at all in the cockpit with regard to the rapidly changing conditions and the impact this may have on the flight. Breaking the cycle of plan continuation bias can be difficult especially where the goal and plan is habitual as scheduled air operations often are. As the goal gets closer the decision the change the plan also becomes harder.
During the descent due to high workload the arming of the spoilers was overlooked prior to landing. dismukes et al. (2007) showed that highly practised normal procedures may be ommited under challenging conditions.
The crew members performance was also degraded by situational stress, fatigue and the captains decision to continue.
Also contributing to the accident were the flight crew's
- impaired performance resulting from fatigue and the situational stress associated with the intent to land under the circumstances,
- continuation of the approach to a landing when the company's maximum crosswind component was exceeded,
- use of reverse thrust greater than 1.3 engine pressure ratio after landing.
Air Crash Investigation Video
Part One
Part Two
Part Three
Part Four
Part Five
Animated Landing
Want to know more?
- Wikipedia - American Airlines Flight 1420
- Wikipedia details of the accident
- NTSB Report DCA99MA060
- The NTSB report on the accident
