What happened
On 19 October 2012, a Boeing 737-804, registration G-GDFJ, was preparing for a commercial flight from Glasgow Airport to Alicante, Spain. During the takeoff roll, the flight crew noted a strange odor, which intensified as the aircraft accelerated. At approximately 80 knots, the cabin crew alerted the flight deck to visible smoke or vapor in the passenger cabin.
In response to the deteriorating situation, the commander initiated a rejected takeoff. The aircraft decelerated using maximum braking and reverse thrust, coming to a halt on the runway. Following the stop, the commander ordered an immediate emergency evacuation. During the process, passengers exiting via the overwing exits encountered slippery wing surfaces due to rain, and some passengers attempting to retrieve items from overhead lockers delayed the movement toward exits. The evacuation resulted in 15 minor injuries and 1 passenger sustained serious injuries.
The investigation
The AAIB investigation examined the aircraft's flight data, cockpit voice recordings, and air conditioning systems. Investigators performed extensive ground runs and borescope inspections of the engines, finding no evidence of fire, leaks, or contamination. Laboratory analysis of the cabin temperature sensor filters showed only general dirt and dust, with no traces of hydraulic fluid or engine oil.
Investigators also reviewed the aircraft's maintenance history and the environmental conditions at the time of the incident. The investigation noted that the aircraft had recently undergone maintenance, and the ambient conditions at Glasgow were highly humid, with the temperature and dew point nearly identical.
Findings
- The primary cause of the perceived smoke was likely the formation of mist or fog in the cabin caused by a sudden influx of cold air from the air conditioning packs into a warm, humid cabin environment.
- The sudden temperature drop, as the air conditioning system worked to reach the selected temperature, likely caused moisture to condense into visible vapor.
- The reported "sparks" seen by passengers were determined to be reflections of runway and aircraft lights off the water spray kicked up by the reverse thrust.
- The evacuation time was extended by passengers attempting to retrieve personal belongings and the commander's thorough check of the cabin to ensure all occupants had departed.
- The injuries sustained during the evacuation were due to passengers colliding on the slides or falling onto the wet ground.