What happened
On 24 August 2002, a Boeint 747-400, registration G-CIVT, was operating a scheduled passenger service from London Heathrow to Toronto. While traversing the Shanwick Oceanic airspace, the crew identified a strong, acrid odor within the cabin, specifically concentrated near the front right area of the aircraft adjacent to door 2R and the galley.
Upon noticing the smell, which the cabin crew described as resembling hot plastic, the crew took immediate precautionary measures. One crew member utilized a smoke hood and applied two fire extinguisher charges to the water heater area within a lavatory. To mitigate potential electrical risks, the crew deactivated power to the in-flight entertainment systems, the galley, overhead lighting, and the trash compactor. After troubleshooting failed to eliminate the odor, the captain decided to divert the flight to Shannon Airport.
The investigation
The investigation focused on identifying the source of the odor and evaluating the crew's response. Following the landing at Shannon, technical personnel inspected the aircraft. This included removing ceiling panels in the affected lavatory to examine electrical wiring and power sources. Maintenance teams monitored the in-flight entertainment and galley systems for two hours, but the smell could not be reproduced.
Further inspections were conducted later that evening by a company engineer from Heathrow, which also yielded no findings. The following day, the flight crew performed high-power engine runs with the air conditioning operating for 10 minutes to check for any signs of electrical burning. These tests were also unsuccessful in reproducing the odor, and the aircraft was cleared for service.
Findings
- The crew initially suspected an electrical fire, with reports suggesting flames might have been visible behind a panel in the lavatory, though no smoke or flames were actually observed by the crew.
- The captain suspected the neon light on the water heater was the source of the odor.
- Extensive technical inspections and engine-running tests failed to identify any permanent damage or a recurring source of the smell.
- There were no injuries reported among the 345 people on board.