Background
The aircraft involved was a Boeing 707-344C, registered ZS-EUW, operated by South African Airways on flight SA228 from Johannesburg to London. The route included stops at Windhoek, Luanda, Las Palmas, and Frankfurt. The first leg to Windhoek was uneventful. Weather conditions at Windhoek were fine, with no cloud and no wind. The night was particularly dark due to the absence of moonlight, making the horizon indistinct.
Accident
At 20:49 local time, the aircraft took off from Windhoek-Strijdom International Airport runway 08 into complete darkness. It climbed to an estimated height of 650 feet above ground level, then leveled off and began descending. Thirty seconds later, the aircraft struck the ground approximately 5,327 meters from the end of the runway. The ground at the impact point was 179 feet below airport elevation, roughly 100 feet below the lift-off point. Impact occurred at a ground speed of approximately 271 knots in a slightly left-wing-down attitude. The fuselage and each of the four engine pods gouged deep trenches, and the aircraft broke apart as it traveled forward. Wreckage was scattered over an area 1,400 meters long and 200 meters wide. Two separate fires broke out, likely from ignited fuel. Five passengers were seriously injured, and 123 other occupants were killed.
Investigation
The official investigation determined that there was no defect in the aircraft, engines, or flight instruments. After a normal takeoff and landing gear retraction, as the aircraft approached 650 feet, the flaps were fully retracted and engine power reduced from takeoff to climb power. These actions were performed at prescribed airspeeds. In that phase, the change in flap configuration and power would cause the aircraft to level off and lose height unless the pilot maintained a climbing attitude or until speed increased. The pilot appears to have believed the aircraft was still climbing and adjusted the stabilizer trim to maintain the same pitch attitude, which was actually a descent. Over approximately 30 seconds, the aircraft lost about 750 feet and struck the ground. The co-pilot failed to monitor flight instruments adequately to notice the altitude loss.
Contributing factors included takeoff into total darkness with no external visual reference, inappropriate stabilizer trim adjustment, spatial disorientation, and pre-occupation with after-takeoff checks. Possible additional factors included temporary confusion from differences in instrument panel layout between the C model and the A/B models to which the pilots were accustomed, misinterpretation of the drum-type altimeter by one thousand feet, and distraction from a bird or bat strike or other minor occurrence.
Probable Cause
The effective cause of the accident was the human factor. After a normal takeoff, the pilot failed to maintain a climbing attitude following flap retraction and power reduction, apparently experiencing spatial disorientation, and the co-pilot failed to monitor instruments. Contributing causes included total darkness, inappropriate stabilizer trim adjustment, spatial disorientation, and pre-occupation with after-takeoff checks.