The pilot had diverted to Wellington because of thick bushfire smoke on his intended track. Take-off was initiated after the smoke had cleared, however shortly after becoming airborne the aircraft sank towards the ground. The pilot subsequently advised that although the engine was developing full power he was unable to prevent the sink from continuing until the aircraft struck the ground heavily, 210 metres beyond the boundary fence of the strip. The 05 strip was used for take-off into a north-easterly breeze. However a witness about 2 kilometres away, along the take-off path, reported that the wind there was from the south. It is likely that at about 200 feet agl the aircraft experienced a head to tail wind change. The pilot attempted to regain airspeed by lowering the nose but the low altitude and rising ground ahead prevented sufficient airspeed to be recovered.
