Incident
During the night of 4 May 2007, a Boeing 737-800, registration 5Y-KYA, operated Kenya Airways Flight KQ507 from Abidjan, Ivory Coast, to Nairobi, Kenya, with a scheduled stopover at Douala International Airport, Cameroon. The weather at Douala was stormy.
Flight Sequence
The aircraft took off and climbed into the dark night. External visual references were absent, and the crew performed no instrument scanning. At an altitude of 1000 feet during the climb, the pilot flying released the flight controls for 55 seconds without engaging the autopilot. The bank angle increased gradually to 34° right, and the captain appeared unaware of the changing attitude. Just before the "Bank Angle" warning sounded, the captain took control and made erratic corrections, increasing the bank angle to 50° right.
At approximately 50° bank, the autopilot was engaged, and the inclination began to stabilize. However, the pilot then resumed flight control inputs, and the bank angle increased toward 70° right. A prolonged right rudder input caused the bank angle to exceed 90°. The aircraft entered a spiral descent and crashed at approximately 0008 local time on 5 May in a mangrove swamp 5.5 kilometers southeast of Douala Airport. The aircraft disintegrated on impact, resulting in the deaths of all 114 occupants.
Probable Cause
The official investigation determined that the airplane crashed after loss of control by the crew as a result of spatial disorientation (non-recognized or subtle type transitioning to recognized spatial disorientation), after a long slow roll, during which no instrument scanning was done, and in the absence of external visual references in a dark night. Inadequate operational control, lack of crew coordination, coupled with the non-adherence to procedures of flight monitoring, confusion in the utilization of the autopilot, also contributed to the situation.