A Piper Archer and a Piper Tomahawk collided at an altitude of about 1,200 ft as the Archer was tracking to enter the crosswind leg for a landing on runway 34 at Hoxton Park aerodrome. The collision occurred in fine and clear conditions, about 0.5 NM east of the upwind end of the runway. Both aircraft were being flown under the visual flight rules (VFR). The pilot of the Archer was able to maintain control of his aircraft and make a successful approach and landing on runway 34, although the nose landing gear had been substantially damaged in the collision. The aircraft was stopped on the runway, resting on the collapsed nose landing gear.
The collision was observed by witnesses who reported that the Tomahawk immediately spiralled down and crashed into an unoccupied house in a suburban housing area. Both occupants were fatally injured. There was no fire and there were no injuries to persons on the ground.
Operations at Hoxton Park are not directed by air traffic control services and rely on pilots seeing and avoiding other aircraft. The aerodrome is located within a common traffic advisory frequency (CTAF) area, extending to a 2 NM radius from the aerodrome and to a height of 1,700 ft. Pilots of radio-equipped aircraft intending to operate within that area are required to make a radio broadcast when approaching the CTAF boundary. That broadcast must include aircraft callsign and type, position, level, and intentions. No other radio report is required prior to landing.
The pilot of the Archer reported that he had made a broadcast on the CTAF when 3 NM inbound to Hoxton Park. He then descended to 1,200 ft and tracked to join the crosswind leg for runway 34, making a "joining crosswind" broadcast while still approaching the upwind end of the runway. He saw another aircraft turning onto crosswind after taking off from runway 34, and a second aircraft on the downwind leg. At about that time, he saw to his left the underside of an aircraft turning to the left, about 50 m away, but skidding towards him at about the same altitude. The pilot of the Archer said he started to turn to the right to avoid a collision, but there was a bang just moments after he first saw the aircraft. He briefly glanced back and saw the aircraft spiralling down to the left. It appeared to him that the outboard end of the right wing of the other aircraft was bent upward at about 45 degrees and that the aircraft appeared to be totally out of control. As he was concerned for the safety of his own aircraft, he concentrated on landing as soon as possible. At no stage prior to the accident was he aware of the presence of the Tomahawk.
Investigation of the wreckage of the Tomahawk indicated that the engine had been torn out during the impact with the house. There was major disruption to the aircraft structure and cockpit area. Small sections from the right wing were scattered about the immediate neighbourhood. The cockpit instruments and controls were too severely damaged to provide any useful information. The very high frequency radio was selected to the CTAF frequency. There was no evidence of any pre-existing defects or abnormalities with either aircraft that may have contributed to the accident.
A metallurgical examination of a section of the right outboard wing from the Tomahawk revealed that a propeller blade of the Archer had first cut through the wing-tip plastic moulding near the trailing edge. The propeller had then cut through the wing at about the mid-chord area before finally striking the leading edge. The action of the propeller blades striking the wing resulted in disruption of the wing structure, with an associated upward bending of the outer section of the wing.