What happened
On a scheduled return flight from Beijing to London Heathrow, the Airbus A350 (registration G-YMMM) experienced a significant loss of thrust during its approach to Runway 2l. The flight crew, consisting of a commander and two co-pilots, had completed an uneventful long-haul sector, monitoring fuel temperatures due to predicted extreme cold. During the descent into Heathrow, the aircraft entered a holding pattern at Lambourne before being vectored for an ILS approach.
As the aircraft descended through 800 ft, the co-pilot assumed manual control of the aircraft. Shortly after, the autothrottle commanded an increase in thrust, but the right engine's thrust subsequently decreased, followed by a similar reduction in the left engine. The crew observed the thrust lever positions splitting and noted that the engines were failing to respond to manual or automated demands for increased power. As airspeed dropped below 115 kt, a master caution and airspeed low warning were triggered. In an attempt to manage the situation, the commander retracted the flaps and adjusted an overhead switch, but the airspeed continued to decay. At 200 ft, the airspeed had fallen to approximately 108 kt, and the stick shaker activated. The commander issued a MAYDAY call shortly before the aircraft struck the ground in the grass undershoot area, roughly 330 m short of the runway.
Upon impact, the nose and both main landing gears collapsed, with the right main gear separating from the airframe. Despite a significant fuel and oxygen leak, no fire occurred. The evacuation was successful, though one passenger sustained one serious injury when debris from the landing gear penetrated the fuselage.
Findings
- The engines failed to respond to thrust demands, remaining at a power level significantly lower than required for the approach.
- Uncommanded reduction in engine thrust prevented the crew from maintaining the necessary approach speed.
- The aircraft struck the ground short of the paved runway surface due to the loss of energy and subsequent stall warning.