Investigation Summary
The flight was operating in a high-workload environment characterized by severe thunderstorms, wind shear, and rapidly falling atmospheric pressure. During the descent, the First Officer incorrectly set the altimeter to 29.47 inHg instead of the 29.40 inHg provided by ATC, causing the aircraft to fly approximately 70 feet lower than indicated. Furthermore, the actual pressure at the airport had dropped to 29.23 inHg by the time of the approach, a change that was not relayed to the crew by the approach controller. As the crew conducted the VOR approach to Runway 15, they failed to level off at the MDA of 908 feet. The First Officer, distracted by looking for the runway, did not provide the required altitude callouts. The aircraft descended 309 feet below the indicated MDA, striking trees on a ridge 2.5 miles from the runway. The impact caused a double engine flameout. In a final act of airmanship, the Captain lowered the flaps to 40 degrees just before landing, creating a 'balloon effect' that provided enough lift to clear the airport perimeter fence and reach the runway surface.
Final Conclusions
The NTSB determined the probable cause was the flight crew's failure to maintain the required minimum descent altitude until visual references were in sight. Contributing factors included the approach controller's failure to provide a current altimeter setting and the crew's failure to request one despite knowing the ATIS was outdated. The investigation resulted in 13 safety recommendations, including changes to approach designs and ATC altimeter procedures. The NTSB also credited the crew's resource management and flying skills for preventing a catastrophic loss of life after the initial impact.
Photographic Evidence (1)
Video Analysis
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Kenneth Lee, age 39
First Officer
John Richards, age 38
Systems & Failure Modes
Altimeter
The crew used an incorrect pressure setting (29.47 vs 29.40) and lacked the most current update (29.23), leading to a significant altitude error.
Pratt & Whitney JT8D-219 Engines
Both engines suffered flameouts after ingesting tree branches and debris during the initial impact on Peak Mountain.
Autopilot
The Captain used the Vertical Speed mode to descend but failed to ensure the Altitude Hold captured the MDA.
Interesting Facts
- 01The aircraft struck trees at a height of 770 feet on a ridge with a ground elevation of 728 feet.
- 02The actual barometric pressure at the time of the crash was 29.15 inHg, significantly lower than the 29.47 inHg set by the crew.
- 03The Captain used a non-standard flap setting (40 degrees) to gain a momentary lift 'balloon' to clear the airport fence.
- 04The aircraft sustained 9 million dollars in damage but was repaired and returned to service; secondary records indicate it remained in service until 2017.
- 05American Airlines was the only U.S. carrier at the time using QFE (atmospheric pressure at field elevation) for approaches.
- 06One passenger sustained minor injuries during the impact or subsequent evacuation; all other 77 occupants were uninjured.
Safety Actions & Advisories
Altimeter Setting Procedures
The NTSB recommended that ATC controllers be required to provide updated altimeter settings to aircraft on instrument approaches when the pressure is falling rapidly.
Approach Design Review
The FAA was directed to review the VOR Runway 15 approach at Bradley to account for the precipitous terrain of Peak Mountain.