Incident Overview
On 21 January 2002, Crossair flight CRX 3874, a Saab 2000 registered as HB-IYH, departed Zurich Airport at 08:12 UTC for a scheduled flight to Luxembourg. During the climb, a fire broke out in an oven in the galley. The crew immediately declared an emergency and turned back to Zurich. The cabin crew successfully extinguished the fire, and the aircraft landed safely at 08:21 UTC. All 24 passengers and 4 crew members were uninjured.
Aircraft and Crew
The aircraft was a Saab 2000 twin-turboprop, operated by Crossair. The cockpit crew consisted of a captain and a first officer, with the first officer acting as pilot flying. Two flight attendants (F/A 1 and F/A 2) were on board. F/A 1 occupied the forward jump seat, while F/A 2 was seated at the rear jump seat near the galley.
Details of the Flight
Shortly after takeoff from runway 28, F/A 2 activated both ovens in the galley. Within minutes, smoke and flames emerged from the right oven. F/A 2 attempted to extinguish the fire using the onboard fire extinguisher and succeeded. Meanwhile, the cockpit crew received the fire warning, declared an emergency, and initiated a return to Zurich. The aircraft landed without further incident.
Investigation revealed that two days earlier, on 19 January, an agent had used both ovens normally. On 20 January, another flight attendant inspecting the right oven found the removable rear wall dirty with residues of melted plastic, described as "white translucent silicone." The circuit breaker for the oven was not engaged, indicating the oven was connected to the aircraft's electrical system. The flight attendant removed the rear wall and set it aside for cleaning, but it was not taken by the catering service until after the aircraft returned to Zurich on the day of the incident. The oven was then operated despite the missing rear wall.
Investigation Findings
The Swiss AAIB (BFU) determined that the fire originated from an oven insert contaminated with a highly flammable plastic. The oven was operated even though it was missing a component (the rear wall). Additionally, the investigation found that procedures for cleaning or replacing critical galley components were absent or incomplete.
Probable Cause
The serious incident was caused by a fire that broke out during flight in an aircraft oven because an oven insert was contaminated with a highly flammable plastic. Possible contributing factors included operation of the oven despite missing parts and incomplete or missing procedures for cleaning or replacement of critical galley components.