Night Training Flight Accident at Douala Airport (TJ-ABC)

Incident Overview and Sequence of Events The aircraft was conducting a local night training flight at Douala Airport. Earlier in the afternoon, the crew completed several maneuvers with alternating departures from runway 12 and runway 30. During a subsequent takeoff from runway 12, the airplane had difficulty gaining altitude after liftoff. The propeller on engine number 2 struck a tree located 1,200 meters beyond the runway end. The aircraft continued at low altitude and struck a second tree, rupturing a fuel tank and causing a fire. The propellers on engines number 1, 2, and 4 detached, and the aircraft crashed in a large explosion 200 meters farther on. All five crew members were killed. ## Official Findings and Contributing Factors The official investigation attributed the accident to flight at too low an altitude during a night training exercise. Witnesses reported that the instructor had directed the pilot to circle the runway at 150 feet during an earlier training exercise, and that this instruction appears to have been maintained for the night exercise. The investigation estimated that the flight lasted 30 to 40 seconds from takeoff to impact with the first tree. It noted that landing-gear retraction takes about 15 seconds and flap retraction about 10 seconds, and that rapid flap retraction at low speed can cause the aircraft to nose down. The report stated that the normal climb path of a DC-4 with one engine on reduced power at takeoff, at 400 to 500 feet per minute, would not have allowed the aircraft to clear the tree tops. It also noted that the Air France DC-4 manual prohibited counter-rotating an engine propeller in case of hydraulic lock, but that this prohibited maneuver did not appear to be a cause of the accident. The investigation concluded that the accident should be ascribed to lack of seriousness and judgment on the part of the instructor, and that pilot fatigue after a two-hour low-altitude training flight under constant supervision may also have been a factor.