What happened
On 19 February 2007, a BAe 146-300, registration D-AEWB, was performing a commercial passenger flight departing from Birmingham. Approximately 15 minutes into the climb, the flight crew noticed a burnt or exhaust-like odor in the cockpit. While no visible smoke was present, the crew and two cabin crew members began experiencing physical symptoms, including tunnel vision, loss of balance, and numbness in the hands and lower arms.
In response to the unusual smell, the crew implemented the 'SMOKE/FUMES ON FLIGHT DECK/CABIN' abnormal checklist and donned oxygen masks, breathing 100% oxygen. This action led to a significant improvement in their physical condition. An emergency was declared, and the aircraft returned to Birmingham. The landing was completed without incident, and the aircraft stopped on taxiway ‘C’ to allow the airport fire service to investigate. All 61 passengers were safely disembarked via bus.
The investigation
The AAIB investigation established that the source of the odor was an oil leak originating from the No 1 engine. Specifically, evidence of leakage was discovered on a bleed band of the engine. This leak allowed engine oil fumes to be ingested into the aircraft's bleed air system, which subsequently contaminated the air supply for both the cockpit and the cabin.
Following the event, the No 1 engine, serial number LF05407AC, was replaced. Subsequent inspections of the aircraft's air supply confirmed that the contamination had been cleared, and the aircraft was returned to service. The five crew members involved attended a hospital for medical evaluations, but no long-term health issues were identified.
Findings
- The primary cause of the incident was an oil leak from the No 1 engine.
- The leaked oil entered the bleed air system, contaminating the air supply to the cockpit and cabin.
- The prompt use of oxygen masks by the crew prevented further physiological distress and contributed to the stabilization of their condition.