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.
