The pilot had taken part in a flour bombing and balloon bursting competition and was returning to land. The front seat passenger was a flying instructor and was acting as a safety pilot and judge for the competition. The approach to land was high and the pilot decided to go around, however, the safety pilot suggested that sufficient strip remained for completion of the landing. The aircraft touched down about 600 metres beyond the runway threshold and bounced. The pilot applied some power and continued with the landing attempt, but the stall warning sounded and the airspeed was noted to be below 40 knots. The front seat passenger retracted flap to the take-off setting and instructed the pilot to apply full power and to lower the nose of the aircraft. He then placed his hands on the controls to monitor the pilot's control inputs. The aircraft failed to accelerate as it flew along the strip about a metre above the ground. It subsequently struck the airfield boundary fence before coming to rest 160 metres beyond.