What happened
On 10 February 2005, a DHC-8-402 Dash Eight, registration G-JEDP, was performing a scheduled passenger flight from Glasgow to Birmingham. During the initial takeoff roll from Runway 23, the aircraft's takeoff configuration warning horn activated, prompting the pilot to abort the takeoff at approximately 10 knots. After vacating the runway, the crew performed standard checks and prepared for a second attempt. During this process, the engine bleed air valves were switched to the ON position.
Shortly after this adjustment, a burning smell was noted on the flight deck. The crew was then alerted by cabin attendants that smoke and a burning odor were present in the passenger cabin. The commander halted the aircraft on the taxiway and initiated an expedited disembarkation through the forward door. While no injuries were reported among the 74 passengers or 4 crew members, the cabin crew reported symptoms of headaches and vomiting due to the smoke.
The investigation
Investigators examined the aircraft's systems and the engine components following the event. While the cause of the initial warning horn activation could not be determined, the engineering investigation focused on the source of the smoke. Maintenance personnel discovered cracking in the inter-compressor case struts of the right-hand engine.
Further inspection by the engine manufacturer, Pratt & Whitney Canada, revealed that a 38 mm piece of the compressor inner support had detached. This failure caused damage to a compressor oil seal, allowing oil to leak into the engine bleed air. When the bleed valves were engaged, this contaminated air entered the air conditioning system, resulting in the smoke observed in the cabin.
Findings
- The smoke in the cockpit and cabin was caused by oil contamination of the air conditioning system.
- A fragment of the right-hand engine compressor inner support had broken away.
- The detachment of this component damaged a compressor oil seal, allowing oil to enter the engine bleed air.
- The activation of the takeoff configuration warning horn could not be identified.