What happened
On 5 August 2003, a Beech 2/00 Super Kingair, registration G-ROWN, departed Biggin Hill Airport in Kent. During the initial after-takeoff procedures, the pilot attempted to retract the landing gear. While the selector handle was moved to the UP position, air traffic control notified the pilot that the gear remained extended. Upon inspection, the pilot observed that the 'Gear Unsafe' red light was illuminated and could not confirm the status of the three green lights.
In an attempt to rectify the situation, the pilot selected the gear to the DOWN position to recycle the system, but found he was subsequently unable to select the UP position. After a fly-past of the control tower confirmed the gear appeared to be down, the pilot decided to return to the airfield. During the landing roll, the aircraft veered left and the landing gear collapsed. The pilot immediately shut down the engines and evacuated the two passengers and himself from the aircraft. There were no injuries during the incident.
The investigation
Investigators examined the aircraft and found that all three landing gear legs had collapsed. The nose landing gear remained sufficiently extended to prevent the propellers from striking the ground, but the main landing gear had almost completely retracted. This caused severe abrasive damage to the nacelles, flaps, and the underside of the fuselage frames and skin.
Technical examination revealed that the 60 amp circuit breaker for the motor was tripped. The investigation also noted that the main landing gear actuator attachment fittings had failed because they had taken the weight of the aircraft, indicating the gear was either not locked at touchdown or became unlocked during the roll. While the pilot believed he was prevented from selecting the UP position, the investigation focused on the electrical components and the squat switch mechanism.
Findings
- The primary cause of the gear collapse was that the main landing gear was not locked at touchdown or became unlocked during the landing roll.
- The pilot failed to follow the established procedure of isolating the landing gear control circuit breaker and using the emergency manual extension mechanism when the 'three greens' could not be confirmed.
- An electrical issue likely prevented the gear from retracting fully, though this occurred after the downlocks had already been released.
- The tripped 60 amp circuit breaker suggests the motor attempted to extend the gear against the aircraft's weight while the legs were unlocked.