History of the Flight
On 8 July 2017, a Boeing 757-28A, registration G-OOBC, operated a commercial passenger flight from Manchester to Girona Airport, Spain. Approximately 15 minutes after takeoff, a cabin crew member switched on the forward galley ovens in preparation for the in-flight drinks service. Upon returning to the galley a few minutes later, the crew member observed smoke emanating from both ovens. The circuit breakers for the ovens were pulled, and assistance was requested from other crew members. A BCF extinguisher was discharged into each oven, and the commander was informed. The smoke did not dissipate or reduce, so a second BCF extinguisher was used, also with no noticeable effect. The commander was updated, and the decision was made to divert to London Gatwick. After landing, the aircraft taxied onto a stand where Airport Fire and Rescue Service personnel confirmed no further fire hazard. Ground staff assisted with passenger disembarkation, and three cabin crew members received medical assistance on board before being taken to hospital for checks.
Investigation
Examination of the forward galley ovens confirmed the presence of a fluid inside both ovens. The ovens were removed for cleaning and testing. Inspection of the rear galley ovens also revealed contamination with a similar fluid. The rear ovens were cleaned and tested, producing no smoke. The fluid in both the forward and rear ovens was identified as a degreasing fluid commonly used for removing chewing gum from carpets, not the approved oven cleaning fluid. The aircraft ovens had been deep cleaned 48 hours prior to the incident flight, and the incident flight was the first operation since that cleaning. The aircraft operator and the contracted cleaning company reviewed the approved oven cleaning instructions, which were unambiguous and specified the correct cleaning fluid. The cleaning company's investigation appeared to confirm that the deep clean had been completed in accordance with approved instructions, using the correct fluid. It was not possible to determine when or how the ovens became contaminated with the degreasing fluid.