NTSB's synopsis of its final report on the December 29, 2010 overrun of American Airlines Flight 2253 at Jackson Hole is up.
This incident's chain of events started with a manufacturing defect that prevented the plane's speed brakes from automatically deploying, investigators found. Then, a "rare mechanical/hydraulic interaction" caused the thrust reverses to lock before full deployment. The experienced flight crew faced an unusual (and of course unexpected) combination of challenges, and had little time to react. The result: a runway excursion. Nobody was injured; the Boeing 757 had minor damage.
The board issued three new recommendations based on the incident and investigation. Quoting the synopsis:
1. Require all operators of existing speedbrake-equipped transport-category airplanes to develop and incorporate training to specifically address recognition of a situation in which the speedbrakes do not deploy as expected after landing.
2. Require all newly type-certificated 14 Code of Federal Regulations Part 25 airplanes to have a clearly distinguishable and intelligible alert that warns pilots when the speedbrakes have not deployed during the landing roll.
3. Require Boeing to establish guidance for pilots of all relevant airplanes to follow when an unintended thrust reverser lockout occurs and to provide that guidance to all operators of those airplanes.
NTSB used its conclusions to reiterate past recommendations (.pdf) that industry develop enhanced flight crew training on "single and multiple emergency and abnormal situations." The board also renewed its call (.pdf) for training programs to both incorporate and practice workload monitoring and management skills.