What happened
On 24 October 1999, a Lockheed L1011-385-1, registration 9Y-TGJ, was operating a public transport flight into London Heathrow Airport. Prior to arrival, the crew notified Heathrow Tower that the number one engine had been shut down due to a flame out, and they estimated landing on runway 09L at 0928 hrs. In anticipation of the arrival, airport authorities initiated a 'Local Stand By' at 0925 hrs.
Following a standard landing, the aircraft exited the runway. Shortly thereafter, Air Traffic Control observed flames emanating from the number one engine cowling. This prompted the upgrade of the emergency status to an 'Aircraft Ground Incident' at 0929 hrs, resulting in the immediate closure of runway 09L and forcing one inbound aircraft to perform a missed approach. The Airport Fire Service responded to the scene and applied foam to the engine area.
The investigation
The investigation examined the sequence of events leading to the fire and the mechanical state of the engine. It was established that while the engine had been shut down following a flame out, the fuel High Pressure Shut Off Valve had remained in the open position.
Findings
- The fire originated in the number one engine cowling.
- The fire was caused by fuel entering the combustion section and migrating to the exhaust area.
- The ignition of this fuel was triggered by the selection of 'Continuous Ignition' which is required for the landing phase of flight.
- There were no fatalities and no injuries to the 12 crew members or 212 passengers on board.