Investigation Summary
During a scheduled flight from Washington, D.C. to West Palm Beach, the DC-9-31 entered the overhang of a thunderstorm cell while cruising at FL310. Company flight operations procedures specifically prohibited flight through thunderstorm overhangs, yet the captain allowed the aircraft to continue into the anvil. The resulting turbulence encounter was severe enough to cause significant injuries to passengers who were standing in the aisles, using the lavatories, or seated without their belts fastened. Investigation revealed that the seat belt sign had remained on for the duration of the flight from takeoff until the accident. Despite this, flight attendants admitted they had not enforced the instruction, and passengers had ignored the briefing to remain seated with belts fastened while the light was illuminated. The fatality involved an 84-year-old passenger who suffered blunt trauma, eventually succumbing to aspiration pneumonia and pneumothorax nearly three weeks after the event. The medical examiner also noted that occlusive coronary atherosclerosis was a significant contributing factor to the passenger's death.
Final Conclusions
The National Transportation Safety Board determined the probable cause was the captain's failure to follow procedures and improper in-flight planning by entering the thunderstorm overhang. Contributing factors included the passengers' failure to abide by seat belt instructions and the flight attendants' failure to enforce those instructions. The NTSB Final Report was published on March 31, 1993.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Age 49, Male. Held Airline Transport rating.
Systems & Failure Modes
Weather Radar
Used by the crew to detect and navigate around convective activity; the captain failed to use radar data to avoid the thunderstorm overhang.
Passenger Service System (Seat Belt Sign)
The visual indicator used to command passengers to remain restrained; it was active during the entire flight.
Interesting Facts
- 01The aircraft was flying through the overhang of a thunderstorm, which was contrary to Eastern Air Lines flight operations procedures.
- 02The seat belt sign had been illuminated continuously from the time of departure.
- 03All injured passengers were either standing in the aisle, in lavatories, or in seats without their belts fastened.
- 04The fatal injury involved an 84-year-old passenger who died 20 days post-accident from aspiration pneumonia and pneumothorax.
- 05The aircraft sustained no structural damage during the turbulence encounter.
Safety Actions & Advisories
Seat Belt Enforcement Emphasis
Source ↗The NTSB highlighted the critical role of flight attendants in enforcing seat belt sign compliance, noting that despite the sign being illuminated for the entire flight, the crew had not ensured passengers remained restrained.