What happened
On 15 November 2005, a Dornier 328-100, registration G-BYML, was taxiing at London (City) Airport for departure to Dundee. During the taxi, air traffic control notified the crew that the aircraft's anti-collision lights were not functioning. While the flight crew investigated the electrical fault, cabin attendants reported a strong smell of burning plastic and observed smoke spreading across the passenger reading lights from the upper ventilation ducts.
As the smoke intensified, the cabin crew experienced difficulty breathing and prepared to use personal breathing equipment. The commander subsequently ordered an immediate evacuation of the aircraft. All 20 passengers and 2 crew members exited the aircraft safely without injury. Following the evacuation, the airport fire service arrived and conducted a search, finding no signs of excessive heat or smoke inside the cabin.
The investigation
The investigation examined two simultaneous issues: the failure of the anti-conliction lights and the presence of smoke in the cabin. Regarding the electrical fault, investigators found that the anti-collision lights power supply unit had been recently replaced and that the circuit breaker would trip whenever the lights were switched on. Inspections of the cable looms and air conditioning pipes showed no evidence of burning or overheating.
Regarding the smoke, the investigation focused on the Environmental Control System (ECS). Although the engineer found no visible oil residue in the pipelines, the description provided by the crew strongly suggested that the ECS pack had been contaminated with oil. The investigation also reviewed the operator's procedures for handling smoke and fumes incidents.
Findings
- The crew experienced two unrelated faults simultaneously.
- The smoke in the cabin most likely resulted from oil leaking from the left engine into the left Environmental Control System pack.
- The anti-collision lights failure was caused by a faulty power supply unit.
- The perceived thickness of the smoke may have been exaggerated by the dimmed cabin lighting used during takeoff preparations.
Safety action
- The operator has since updated its Operations Manual to include specific instructions for flight and cabin crews regarding actions to be taken following a smoke or fumes incident.