What happened
On 1 September 1998, a Boeing 767-322ER, registration N662UA, was on final approach to Runway 09L at London Heathrow Airport. The aircraft was operating a scheduled passenger flight from Washington Dulles with 203 passengers on board. While the aircraft was approximately 50 feet above the runway, it encountered a large flock of Canada geese flying across its flight path. The impact occurred just seconds before touchdown while the engines were at idle power.
Following the encounter, the aircraft completed its landing roll. The commander reported the birdstrike and noted bird debris on the runway. While there were no immediate indications of engine failure, a subsequent inspection revealed significant damage. The aircraft sustained strikes to the nose radome, the left wing leading edge, and the slats and flaps. The left engine showed evidence of bird ingestion, and debris was found on the left and nose landing gears, as well as the left stabiliser. There were no fatalities and no injuries to the passengers or crew.
The investigation
The investigation established that the flock, estimated to consist of between 25 and 30 geese, had not been previously sighted by ground patrols, despite the presence of a bird control vehicle in the area. While a NOTAM had been issued the previous day warning of geese activity, the specific flock involved in the collision was moving in a direction (northbound) that had not been reported to the tower at the time of the strike.
Investigators examined the local environment and found that the Perry Oaks sewage treatment works, located near the airport, served as a significant roosting site for large numbers of waterfowl. The investigation also looked into the growing population of Canada geese in the region, noting that these birds are highly migratory and tend to fly in large, dense flocks, which increases the risk of multiple engine ingestions during a single encounter.
Findings
- The primary cause of the incident was the collision with a large flock of Canada geese during the landing phase.
- The aircraft's left engine, radome, and various airframe components sustained extensive damage due to the impact.
- The presence of large, resident populations of Canada geese at nearby water features, such as the Perry Oaks lagoons, created a persistent hazard.
- Existing ground-based visual patrols were unable to detect the incoming flock before the aircraft entered its final approach.
Safety action
- Recommendation 99-63: Heathrow Airport Limited should work to reduce the attractiveness of the Perry Oaks sewage treatment complex to waterfowl by eliminating unnecessary lagoons.
- Recommendation 2001-32: The Department of the Environment, Transport and the Regions (DETR) should lead a working group involving local authorities and landowners to manage bird habitats around Heathrow.
- Recommendation 2001-33: Development and installation of suitable bird detection radar at Heathrow should be trialed to provide earlier warnings to ATC and pilots.