What happened
On 23 November 2000, a Jetstream 3202, registration G-OEST, was performing a public transport flight at Aberdeen Airport. Shortly after the aircraft began taxiing and had travelled approximately 30 metres, the pilot detected a burning odor. A passenger alerted the flight deck to the presence of smoke within the cabin, and the pilot subsequently observed thick, grey-yellow smoke descending past the right-side passenger windows.
The commander immediately ordered the shutdown of both engines and initiated an evacuation via the public address system. The crew coordinated with Air Traffic Control and accepted assistance from the Airport Fire Service. After deactivating the aircraft's electrical systems, the crew evacuated the aircraft. All 9 passengers and 3 crew members exited the aircraft safely, with passengers reaching the terminal without injury.
The investigation
Investigators determined that the smoke originated from behind the cabin trim, specifically in front of the window transparencies. The odor was described as smelling of plastic, wiring, or toxic materials. Following the incident, the aircraft was moved to a maintenance area where ground runs identified the source of the smoke as the forward right-side power unit for the cabin lighting.
Records showed that a previous Service Bulletin had been implemented on this aircraft in 1991 to replace older lighting units with the TR992-10 model to prevent similar failures. The faulty unit was sent to the manufacturer for a detailed forensic analysis.
Findings
- The investigation established that the internal overheating of a transformer within the lighting unit caused the failure.
- A short circuit on the internal transformer likely caused the varnish-impregnated copper coil to overheat, resulting in a burn-through of the unit's casing.
- This overheating produced the thick, discoloured smoke observed by the crew and passengers.
- The manufacturer noted that this was the first instance of such a failure among the more than 7,000 units of this specific type in service.