What happened
During the takeoff roll at Lagos International Airport, the crew of Associated 361 advanced power to begin the departure on runway one eight left. Shortly after the start of the roll, an automated cockpit warning notified the crew regarding incorrect flap configuration. Despite this warning and subsequent alerts regarding the auto-feather status of the propeller, the Captain elected to continue the takeoff rather than aborting the procedure.
As the aircraft accelerated, the First Officer noted a lack of speed, and evidence indicated that the right engine was producing significantly less thrust than the left engine. The right engine propeller was found in the feathered position following the accident. Although the First Officer inquired about aborting the takeoff at approximately 95 knots, the Captain decided to proceed. The crew failed to announce the critical V1 or Vr speeds during the roll.
During the rotation phase, the First Officer instructed the pilot flying to rotate the aircraft "gently" to avoid a stall, reflecting concerns regarding the aircraft's performance. After lift-off, the aircraft drifted right of the runway and struggled to gain altitude. Within 10 seconds of rotation, a stall warning activated in the cockpit. The flight data recorded characteristics consistent with an aerodynamic stall, and approximately 31 seconds after the warning began, the aircraft type impacted the ground in a steep, nose-down, 90-degree right bank.
Findings
- The crew decided to proceed with the takeoff despite receiving warnings about flap configuration and auto-feathering.
- The right engine suffered from reduced thrust caused by an unidentified malfunction within the propeller control unit.
- The aircraft was rotated before reaching the V1 decision speed.
- The decision to continue the takeoff roll despite known engine and configuration abnormalities led to the loss of control.