What happened
On 14 December 2016, a Cessna F177RG Cardinal RG, registration G-TOTO, was involved in an accident at Denham Aerodrome, Buckinghamshire. The flight was being conducted as a training mission to revalidate a single-engine piston (SEP) class rating for a handling pilot.
During the circuit to Runway 24, the handling pilot performed a flapless approach. As part of this procedure, the pilot retracted the landing gear while on the crosswind leg, just before the turn to downwind. The commander, who was supervising the flight, noted that this was not standard practice for circuit work and intended to instruct the handling pilot to lower the gear once the retraction cycle was complete.
However, the crew became distracted by extended radio communications from two aircraft positioned ahead in the circuit. This distraction was compounded by another aircraft joining the circuit overhead. Consequently, the landing gear was not lowered during the downwind checks. Due to the low sun angle and the need to monitor trees during the flapless approach, the crew failed to notice the gear remained retracted, and the aircraft landed with the gear up.
The investigation
Investigators examined the sequence of events and the aircraft's systems following the incident. The aircraft sustained damage to the propeller, engine, and fuselage. A subsequent maintenance inspection of G-TOTO revealed that the landing gear warning horn was inoperative, which prevented the crew from receiving an audible alert regarding the gear configuration.
Findings
- The primary cause of the accident was the failure to extend the landing gear prior to landing.
- Radio communications from preceding aircraft and the arrival of a new aircraft into the circuit served as significant distractions.
- Environmental factors, specifically a low sun angle and the increased workload of a flapless approach, contributed to the oversight.
- The landing gear warning horn was not functioning, removing a critical safety alert mechanism.