Casualties unknown

Runway Excursion During Reverse Thrust Demonstration in Training Exercise (N978Z)

Saint Louis, MO, US

On March 12, 1993, a Mcdonnell Douglas DC-9-31 (registration N978Z) operated by Trans World Airlines, Inc. was involved in an aviation accident near Saint Louis, MO. Investigators recorded the probable cause as: THE CAPTAIN'S IMPROPER USE OF THRUST REVERSERS AND EXCESSIVE USE OF ENGINE POWER. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE: THE CROSSWIND AND THE FIRST OFFICER'S FAILURE TO RAISE THE FLAPS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

During a training touch-and-go, the captain demonstrated a reverse thrust technique. The airplane departed the runway, dragging the left wing and reverser bucket. Neither reverser was stowed, flaps were full, and a right crosswind was present.

Accident Overview

During the first officer's initial training, the captain elected to demonstrate 'a more efficient reversing technique' using a touch-and-go. The airplane departed the left side of the runway at the 4,000-foot marker, dragging the left wing and lower left reverser bucket. It continued for 2,000 feet before coming to rest.

Evidence from Onboard Systems

Evidence indicated that neither thrust reverser was stowed and that the flaps were at full deployment. McDonnell Douglas Letter #4 states that reverser buckets will not stow with engine pressure ratio (EPR) above approximately 1.2. The digital flight data recorder (DFDR) showed no indication that the airplane completely lifted off the ground once the initial landing was made. It indicated a constant decay of airspeed from the initial touchdown until the airplane stopped.

Environmental and Airplane Manual Considerations

There was a right crosswind at the time of the accident. There was no physical evidence that the nose wheel was in contact with the runway when directional control was lost. The airplane flight manual indicates that increasing amounts of reverse thrust significantly reduces rudder effectiveness.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X11935. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.