What happened
On 2 February 2002, a Cessna 172M, registration G-SEXI, was conducting a private local flight originating from Southend airport. Following a successful pre-flight inspection and a normal takeoff and climb, the engine began to vibrate and cough once the aircraft reached cruise altitude. In response to the engine instability, the pilot applied maximum carburettor heat and checked the magneto settings while diverting to Nayland Airpoint, the closest suitable landing site.
As the engine continued to misfire, the pilot prepared for a precautionary landing on the grass runway 32 at Nayland. This runway is characterized by a significant upward slope. During the approach, the pilot configured the aircraft with two stages of flaps and initiated the flare at approximately 70 knots. Upon touchdown, the aircraft bounced, overran the 600-metre strip, and collided with a hedge at the end of the runway. The impact caused the aircraft to come to rest upside down in a nearby field. All three occupants, including the pilot and two passengers, exited the aircraft without injury.
The investigation
The investigation examined the engine's performance and the pilot's landing technique. While the pilot suggested that carburettor icing might have triggered the engine's irregular running, investigators also looked into the flight parameters during the landing phase. It was noted that the aircraft's speed during the flare was excessively high for the flap configuration used.
Findings
- The engine's coughing and vibration may have been caused by carburettor icing.
- The aircraft overran the runway following a bounce during touchdown.
- The airspeed during the flare was too high given that two stages of flaps had been selected.