Flight Crew and Pre-Flight
The aircraft, a Boeing 737-804 registered G-GDFJ, was scheduled to depart for Alicante, Spain at 0615 UTC. The flight crew, consisting of a commander (age 36, 7,600 total hours, 2,200 on type) and a co-pilot, reported for duty at 0515. The commander acted as Pilot Flying, with the co-pilot as Pilot Monitoring. Before departure, the co-pilot conducted the pre-flight inspection while the commander prepared the flight deck. The Auxiliary Power Unit was in operation, providing lighting and heating. The technical log showed no unserviceable items, and the Daily Inspection had been completed. A 10-minute delay occurred for a passenger. The crew performed the takeoff and departure brief, which included the rejected takeoff procedure.
Takeoff and Smoke Detection
After pushback and engine start, the aircraft taxied to Holding Point G1 for Runway 05. Meteorological conditions included wet runway, slight drizzle, and standing water. Following clearance from air traffic control, the commander aligned the aircraft on Runway 05 and set 40% N1. When both engines were stable, he engaged the Take Off and Go Around (TOGA) mode. As the engines accelerated, both pilots noted a "strange" smell. At about 80 knots, the smell intensified, and a slight misting appeared on the flight deck. Meanwhile, cabin crew and passengers also detected an unusual odor, variously described as hot oil, burning electronics, or burning rubber. Smoke, apparently originating from the area of the overhead lockers, became more visible in the beams of the illuminated reading lights.
Rejected Takeoff and Evacuation
The Cabin Service Director repeatedly pressed the flight deck call button to alert the pilots to the urgent situation. The commander initiated a rejected takeoff, closing the thrust levers, disconnecting the autothrottle, applying maximum braking, selecting the speedbrake fully open, and engaging reverse thrust. The co-pilot acknowledged the actions, advised the commander of the speed, moved the flaps from the takeoff position to 40 degrees, and informed ATC that the aircraft was stopping on the runway. The aircraft came to a halt, and the commander applied the parking brake. He then called the CSD to the flight deck, who reported the smell and smoke in the passenger cabin, clearly visible through the open flight deck door. The commander decided to execute an emergency evacuation on the runway. After completing the evacuation checklist, the commander ordered the evacuation, and the co-pilot notified ATC. Cabin crew opened the aircraft doors, the escape slides inflated, and passengers opened the over-wing exits. All passengers evacuated, followed by the cabin crew and pilots, with the commander being the last to leave.
Post-Evacuation and Investigation
The airport Rescue and Fire Fighting Service, alerted by ATC, deployed to the aircraft. They monitored for fire and, after everyone was clear, entered the aircraft using a ladder but found no signs of fire, only a faint smell of smoke. Coaches transported passengers and crew back to the terminal. Injured individuals received initial treatment at the scene before being taken to hospital. The AAIB distributed a Passenger Questionnaire to gather details of the evacuation. Some passengers attempted to retrieve personal items from overhead lockers, which hindered the flow toward exits. Passengers climbed onto the wings, which were slippery from rain, and could see directional markings. In the dark, visibility of the ground was poor, and some passengers were unaware they should slide down the flap surfaces. On the left wing, some slid down and assisted others; on the right wing, fewer slid, and some re-entered the cabin to use door escape slides.
The investigation was unable to identify a definitive source for the smoke. Excessive moisture in the air conditioning system was identified as a possible factor. Following the event, the operator amended its maintenance procedures.