What happened
On 10 April 2006, a Piper PA-28RT-201, registration G-MERL, was performing a private flight returning to Cardiff Airport. After an initial flight to Bristol Filton, the pilot was directed to orbit the local area before being cleared for the circuit. The aircraft established on the final approach to Runway 30 at a speed between 75 and 80 knots with 25 degrees of flaps selected.
During the flare, the pilot heard a beeping sound which she mistook for the stall warning. Upon landing on the main wheels, the nose gear descended and made contact with the runway surface. There were no injuries to the two occupants. The impact resulted in a bent propeller, as well as scrapes to the engine cowling and the nose landing gear doors.
The investigation
Following the incident, the airport fire service assisted in recovering the aircraft by manually raising the nose and extending the gear. A subsequent inspection of the aircraft revealed no mechanical defects that would have prevented the gear from extending or prevented the indicator lights from functioning. The engineer's assessment suggested the damage was consistent with the nose being lowered gently onto the runway.
An examination of the undercarriage operating and warning system confirmed that the system was fully operational. The investigation also looked into the possibility that the gear selector had been left in the UP position; however, if this had been the case, the backup gravity-extension system would have likely triggered during the descent.
Findings
- The pilot misinterpreted the landing gear warning horn as the stall warning.
- The pilot likely failed to notice that the three green landing gear lights were not all illuminated prior to touchdown.
- The beeping sound of the gear warning horn (90 Hz) was mistaken for the continuous tone of the stall warning.
- It is possible the nose gear was in the process of moving into the downlock position when the aircraft made contact with the ground, or that the selector had been moved to the DOWN position but the gear failed to engage the downlock.