What happened
On 27 August 2024, a Falco F8L, registration G-HCBW, was conducting a training flight at Headcorn Aerodrome in Kent. The flight was intended to provide differences training for a new aircraft owner. During the takeoff roll, the aircraft encountered a runway undulation which caused it to bounce. Due to a crosswind, the aircraft descended onto its left wheel before successfully climbing away.
Upon attempting to retract the landing gear, the pilot observed a red unlocked light and noted that the landing gear circuit breaker had tripped. The gear failed to retract via the normal or emergency systems. Although the pilot reselected the gear to the down position and the green indicator light illuminated, there was uncertainty regarding the actual configuration. After a fly-by to visually confirm the gear position with the assistance of the airfield radio operator, the pilot proceeded to land.
During the landing roll, the aircraft encountered runway unevenness, causing the left wing to drop. The left landing gear leg partially collapsed, folding under the aircraft as it came to a stop on the runway. Both occupants of the aircraft were uninjured.
The investigation
Investigators examined the aircraft's landing gear assembly and discovered that the retraction screwjack had been bent, with accompanying damage to the drive linkages and tube. The investigation focused on the sequence of events starting from the takeoff bounce.
It was determined that the initial bounce, combined with a 90-degree crosswind, likely subjected the left landing gear to excessive side loads. This mechanical stress is believed to have damaged the retraction screwjack mechanism. This damage likely caused the gear to fail to retract and triggered the circuit breaker. Furthermore, while the gear appeared to be locked in the down position, the investigation concluded that the geometric lock within the mechanism had been compromised, leaving the gear vulnerable to the forces encountered during the landing roll.