What happened
Shortly after departing Runway 28L at London Heathrow, the crew of Flight BA. 712 experienced a sudden mechanical shock and a loud bang. The number 2 engine's thrust lever moved toward the closed position, and instruments indicated the engine was losing power. While the flight crew initially initiated an engine failure procedure, they quickly transitioned to an engine fire drill after observing a significant fire on the port side of the aircraft.
During the emergency, several mechanical issues occurred. Approximately 14 minutes into the fire event, the number 2 engine and part of its pylon detached from the wing and fell into a nearby gravel pit. As the crew prepared for landing, they noted that hydraulic pressure loss prevented the flaps from extending to their full range. The aircraft approached Runway 05R at high speed and landed approximately 400 yards beyond the threshold.
Upon stopping, the use of reverse thrust on the remaining engines directed flames toward the fuselage. An explosion in the port wing intensified the fire and caused debris to scatter across the aircraft. During the emergency evacuation, the fire spread under the rear of the plane, causing escape chutes to burst. While most passengers escaped via the forward starboard galley door, 5 fatalities occurred when four passengers and one flight attendant were overcome by smoke and heat at the rear of the aircraft. Additionally, 38 passengers sustained injuries during the evacuation process.
Findings
Investigations determined that the incident began when the number 5 low pressure compressor wheel in the number 2 engine failed due to fatigue. This failure caused damage to the engine cowling and a fuel leak from the supply line, which ignited the fire.
Contributing factors included the failure to close the fuel shut-off valve because the flight engineer did not pull the engine fire shut-off handle. The crew also inadvertently silenced the fire bell instead of the undercarriage warning horn. Furthermore, the existing emergency drills were found to be susceptible to misapplication during high-stress situations.