What happened
On 16 December 2012, a Cessna 172RG, registration G-BILU, arrived at Stapleford Aerodrome in Essex following a flight from Cardiff. As the pilot joined the circuit for Runway 22 and selected the landing gear to the down position, the cockpit indicators provided an ambiguous signal; the green light initially failed to illuminate before turning red. While the main landing gear appeared to be locked in place, the nose gear remained unconfirmed.
The pilot notified the control tower of the intention to perform a go-around to attempt to rectify the situation. During the second circuit, the pilot cycled the landing gear multiple times and utilized the manual hydraulic pump, but the nose gear failed to extend. After a visual inspection by the tower confirmed the nose gear was still not deployed, the pilot performed a forced landing on the grass area to the left of Runway 22. There were no injuries to the pilot, though the aircraft sustained damage to the engine, propeller, and landing gear doors.
The investigation
Following the incident, the aircraft was inspected to determine why the nose gear failed to deploy. Investigators found that the nose gear was physically prevented from extending because it was being jammed by the gear doors. A review of the retraction system's components revealed that several bushes and linkages related to the gear door mechanism exhibited significant wear. Subsequent testing of the retraction system itself did not reveal any other operational anomalies.
Findings
- The nose landing gear failed to extend because it was jammed by the gear doors.
- The jamming was caused by the cumulative effect of wear within the linkages and bushes associated with the gear door mechanism.