What happened
On 22 June 2014, a modified Stampe SV4C, registration G-BPLM, was conducting a private flight from Clutton Hill in Somerset to Headcorn in Kent. While passing Redhill, the pilot confirmed there was adequate fuel for the remaining 25 nm of the journey. As the aircraft approached the area west of Paddock Wood at approximately 1,700 ft amsl, it encountered a particularly intense thermal. Shortly after this turbulence, the engine began to malfunction with a noticeable cough.
Believing the engine irregularity to be significant, the pilot intended to perform an immediate landing at Old Hay Airfield, located 1 nm east of Paddock Wood. However, the engine subsequently ceased operation. After verifying the fuel, mixture, and magneto settings, the pilot prepared for an emergency landing in a nearby field. As the aircraft descended to roughly 100 ft, the pilot identified that the field contained rapeseed rather than the expected hay. In an attempt to decrease the aircraft's approach speed, the pilot executed a deep stall just above the crop. Upon touchdown, the undercarriage became entangled in the dense rapeseed, causing the aircraft to pitch forward onto its back. The pilot, who was uninjured, released his harness and exited the aircraft.
The investigation
The investigation was based on the accident report submitted by the pilot. The examination focused on the sequence of engine malfunctions following the encounter with a thermal and the subsequent landing dynamics. The aircraft sustained damage to the rudder, the spinner and cowling, and the upper surfaces and leading edges of the wings.