Serious Incident Involving Africa Airlines ATR 72-212A TN-AKA on 29 July 2023

Overview and Investigation Authority On 29 July 2023, a serious incident occurred during a commercial cargo flight operated by Africa Airlines. The aircraft involved was an ATR 72-212A with registration TN-AKA, operating flight AAT 102 from Brazzaville (FCBB) to Pointe-Noire (FCPP). The incident was investigated by the Bureau des enquêtes et des accidents d’aviation of the Republic of Congo under investigation number BEA-02-2023. ## Flight Details and Crew The aircraft departed Brazzaville at 10:48 local time. The flight deck included a captain serving as pilot flying, a first officer as pilot monitoring, and an ATR sector chief seated in the center jump seat. The aircraft’s takeoff mass was 22,058 kg, with 1,800 kg of fuel. The weight rotary selector was set to 21.5 tonnes. ## Incident Sequence At 10:50:51, while climbing through 3,500 feet, the autopilot was engaged. The active modes were indicated airspeed at 170 knots, heading 272 degrees, and a target altitude of FL160. Three seconds later, a caution message appeared on the Advisory Display Unit. At 10:51:38, the Touch Control Steering function was activated, and the ADU message disappeared. During this period, the flight was asymmetric, with a left slip. The aircraft exhibited a bank angle of approximately 5 degrees to the left, and the yaw indicator showed a persistent left deviation. The magnetic heading oscillated between 272 and 276 degrees. A repetitive sequence of ADU messages, including “RETRIM ROLL L WING DN” and “AILERON MISTRIM,” occurred alongside activations of the Touch Control Steering function. ## Consequences The report states that there were no injuries or damage to the aircraft. The investigation included participation from multiple international organizations, including the French BEA, the Canadian TSB, the U.S. NTSB, ATR, Pratt & Whitney Canada, Honeywell, and the European Union Aviation Safety Agency.