The U.K.’s Air Accidents Investigation Branch (AAIB) has released its final report on a “serious incident” involving a British Airways Boeing 777-200 aircraft that performed a rejected takeoff at London Gatwick Airport on June 28, 2024.

Investigators determined the incident occurred when the first officer inadvertently began reducing the throttles at the V1 decision speed instead of removing his hand from them as required by procedure.

“The co-pilot began retarding the thrust levers at airspeed V1, instead of removing his hand from them. After momentarily advancing them again, he initiated the rejected takeoff procedure around 2 KIAS later,” the AAIB report stated.

Incident Timeline

The incident occurred as the flight to Vancouver, Canada, was departing from Runway 26L at London Gatwick Airport with 334 passengers and 13 crew members on board. According to the investigation, when the aircraft reached V1 speed (160 knots), the first officer, who was the pilot flying, inadvertently pulled back the thrust levers instead of following standard procedure to remove his hand.

After recognizing the error, the co-pilot momentarily advanced the thrust levers again before deciding to commit to a rejected takeoff at approximately 162 knots. The aircraft reached a maximum speed of about 167 knots before coming to a stop well before the end of the runway.

Airport firefighters responded to the scene to extinguish a fire that developed on the right-side main wheel brakes due to the heavy braking action. No injuries were reported among passengers or crew.

The 777 remained out of service for around four days following the incident.

The AAIB classified the event as a serious incident resulting from what human factors specialists term an “action slip” – an unintended action that occurs during routine or highly learned motor sequences.

The first officer, who had 6,156 total flying hours with 2,700 hours on the aircraft type, was returning from annual leave, having last flown on June 14, 2024. Investigators noted that he “expressed surprise in himself over the inadvertent thrust reduction and could not identify a reason for it.”

Weather conditions at the time were favorable with an 11-knot headwind and a dry runway surface. The aircraft was operating approximately 20 metric tons below its maximum takeoff weight.

“The incident emphasizes the complex nature of the takeoff roll,” the report stated. “Pilots perform a series of motor actions during a normal takeoff, while also mentally preparing themselves to decide upon and enact different action sequences for an RTO.”

Preventive Measures

The investigation revealed that the operator had already identified the risk of action slips in flight operations. Just four days before the incident, the airline had released an Operational Safety Notice addressing control movement errors, recommending that pilots “pause before execution, and cognitively consider what the required action is, methodically execute the action, confirm correct execution.”

In its report, the agency noted that British Airways “has included the wider issue of ‘focus’ in its recurrent simulator training” and has been cautious about publicizing specific incidents to avoid inadvertently priming crews to make similar errors.

“Pilots can improve their individual performance by mentally rehearsing what might seem like routine parts of an operation, especially after time away from flying,” the report concluded.