What happened
On 8 July 1999, a Boeing 737-236, registration G-BGDL, was performing a scheduled public transport flight from London Gatwick Airport. During the initial climb, at an altitude between 100 and 200 feet, the aircraft experienced a loud bang accompanied by a momentary oscillation in roll and a shudder throughout the airframe. This occurred while the landing gear was in the process of retracting.
While the flight crew initially observed normal engine parameters, a strong, pungent odor soon permeated both the flight deck and the passenger cabin. A passenger alerted the crew to visible flames emerging from the left engine for a brief period. In response to the situation, the pilot declared a 'Pan' Pan call and initiated an immediate return to Gatwick, where the aircraft landed safely with no injuries to the 6 crew members or 63 passengers.
The investigation
Investigators examined the aircraft following the incident and identified physical damage to the No.1 engine intake. The inspection confirmed that a fan blade had sustained damage and the oil cooler for the constant speed drive (CSD) had been blocked and damaged.
To determine the cause of the impact, bird remains recovered from the engine were analyzed by the Central Science Laboratory's Birdstrike Avoidance Team. Microscopic analysis of the feathers confirmed that the debris originated from a pigeon.