On passing Redhill, during a flight from Clutton Hill in Somerset to Headcorn in Kent, the pilot checked he had sufficient fuel for the remaining 25 nm of the flight. Just west of Paddock Wood, at 1,700 ft amsl, the aircraft was caught in a “particularly harsh” thermal, shortly after which the engine “coughed”. The pilot considered this to be so unusual that he decided to land immediately at Old Hay Airfield, 1 nm east of Paddock Wood; however, the engine then stopped. He checked the mixture, fuel and magnetos and set up for a forced landing in what looked like a hay field. At about 100 ft, positioned to land a third of the way into the field, the pilot realized the crop was rapeseed which he knew was much denser than hay. To try to reduce his forward speed on touchdown, he “deep stalled” the aircraft just above the crop; however, the undercarriage caught in the rapeseed and the aircraft slowly pitched over onto its back. With the magnetos and fuel off, he released his full harness and additional lap strap before vacating the aircraft unhurt. The pilot suspected that the problem was caused by the carburettor’s float needle jamming in its base – a problem he was aware had occurred on another Stampe at Headcorn in 2013.