Synopsis
The aircraft, a Beech 76 Duchess registered G-JLRW, experienced a failure of the left main landing gear to extend during a training flight at Exeter Airport on 22 March 2017. Examination revealed that the lower clevis pin in the trailing link of the left main gear was missing. The pin was not recovered, preventing a determination of why it was absent.
History of the Flight
The aircraft was conducting a dual training flight for a Multi-Engine Piston rating. The pilot under training performed a full pre-flight 'A' Check; no landing gear defects were noted. The initial phase of the flight was normal. However, when the landing gear was lowered, the left gear indicator light failed to illuminate and the gear unsafe light remained on. Recycling the gear and replacing the indicator light bulbs did not resolve the issue. Upon returning to Exeter, the emergency gear lowering procedure as per the checklist was attempted but was unsuccessful. A flypast of the tower confirmed that the left gear had not extended.
For approximately 45 minutes, the aircraft was flown in the local area while the pilots discussed alternative courses of action with operations and the engineering organization. This also allowed consumption of additional fuel before landing.
Landing and Evacuation
With the gear problem unresolved, the pilots briefed for an approach and landing, with the instructor flying the aircraft. Both engines were shut down and the propellers feathered as the aircraft crossed the Runway 26 threshold. The pilot under training positioned the propeller blades horizontally and isolated the fuel and electrical systems. After touchdown, the aircraft veered to the left and came to a stop on the grass beside the runway. Both pilots evacuated the aircraft normally.
Examination
A subsequent examination of the left main landing gear revealed that the lower clevis pin in the trailing link was missing. The pin was not recovered, so the reason for its absence could not be determined. Damage from the incident was limited to the left pitot tube and left foot step. No injuries were sustained by the two crew members.
Probable Cause
Not determined; the missing clevis pin could not be examined, and no cause could be established.