Investigation Summary
Flight 508 was a multi-leg commuter service that originated in New Orleans before stopping in Mobile to change crews and board 12 additional passengers. As the flight neared Birmingham, the local weather deteriorated rapidly with strong to severe thunderstorms. While four other aircraft in the vicinity chose to divert or enter holding patterns, the crew of Flight 508 proceeded with the approach. The captain later reported that the aircraft experienced a significant roll to the left followed by an extreme updraft that pitched the nose up. The NTSB investigation utilized weather radar images recorded by local television station WBRC to reconstruct the storm's intensity at the time of the crash. The investigation also benefited from a cockpit voice recorder, which was notably present despite not being legally required for that aircraft type at the time.
Final Conclusions
The National Transportation Safety Board (NTSB) issued its final report, AAR-92/01, on March 3, 1992. The board determined the probable cause was the captain's decision to initiate and continue an instrument approach into clearly identified thunderstorm activity. This decision resulted in a loss of control and subsequent collision with obstacles and terrain. The crash killed the first officer and 12 passengers, while the captain and one passenger survived with injuries.
Video Analysis
The deadly 1991 crash of L'Express Airlines Flight 508 in Birmingham — A retrospective look at the 1991 crash of L'Express Airlines Flight 508, which struck homes in the Ensley neighborhood during a severe thunderstorm.
If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Cockpit Voice Recorder (CVR)
A device used to record the audio environment in the flight deck. Although not required for this aircraft type in 1991, its presence provided investigators with critical data regarding the crew's decision-making.
Weather Radar
Ground-based and airborne systems used to detect precipitation. The crew was aware of the storm cells via their instruments and ATC reports but failed to divert.
Interesting Facts
- 01The aircraft was a Beechcraft C99 twin-engine turboprop.
- 02Thirteen people on board were killed, including the first officer and 12 passengers.
- 03The captain and one passenger survived the crash.
- 04Four residents on the ground were injured, but there were no ground fatalities; some media reports erroneously claimed four ground deaths.
- 05The NTSB found that the aircraft was equipped with a cockpit voice recorder even though it was not required by regulations.
- 06Local television station WBRC provided weather radar images that were used as evidence in the NTSB investigation.
Safety Actions & Advisories
CVR Requirement Advocacy
Source ↗The NTSB used the presence of a non-required CVR to highlight the value of such devices on smaller commuter aircraft, supporting future mandates for flight recorders on Part 135 operations.
Known Controversies & Unanswered Questions
Conflicting Ground Fatality Reports
Reference ↗While the NTSB and major aviation databases record zero ground fatalities (with four residents injured), some local media outlets, including WVTM 13, have erroneously reported that four people on the ground were killed in the accident.