What happened
On 06 December 2021, a Cessna 120, registration G-OVFM, was returning to South Cave (Mount Airy) Airfield following a private flight. Upon arrival, the pilot performed an overflight of the runway to check the windsock, which indicated that Runway 25 was the most suitable option.
During the final approach, the aircraft touched down further down the runway than intended. Because the runway featured a 2.3% downhill gradient and the grass surface had been made slippery by recent rain showers, the aircraft's braking effectiveness was significantly reduced. The aircraft's wheels were fitted with slick tundra tyres, which caused them to skid when brakes were applied. Realising there was insufficient distance to stop but determining there was not enough space to take off and clear the trees at the end of the runway, the pilot continued the landing. The aircraft subsequently overran the runway and struck a hedge. There were no injuries to the pilot or the passenger.
The investigation
Following a report from a third party, the AAIB examined the aircraft. The inspection revealed that the right main landing gear leg had been displaced rearwards, causing the fuselage to buckle and twist behind the gear mount. Additional damage included a crack in the right wing root, as well as damage to the engine cowlings and the propeller.
Findings
- The landing was long and fast on a wet, downhill grass runway.
- Reduced braking effectiveness was caused by the slippery surface and the use of slick tundra tyres.
- The aircraft's weight was near its maximum takeoff mass due to the presence of a passenger, which the pilot was less accustomed to managing than solo flights.
- The pilot's familiarity with the aircraft and airfield may have led to less diligent flight planning regarding changing weather conditions.
- The pilot's experience with a different aircraft type, a Cessna 172, may have influenced expectations regarding deceleration, as the Cessna 120 lacks flaps.