The Ayers Turbo Thrush aircraft was conducting water-bombing
operations in support of bush fire-fighting activities. Three
missions had been flown during the preceding 2 hours, using runway
05. Following the third mission, aircraft operations were suspended
and the aircraft was refuelled. During refuelling the pilot was
tasked to drop a load of retardant in another location. The pilot
assessed the wind to be from the northeast and lined up for
departure on runway 05. The aircraft had a full load of retardant
on board. The pilot reported that during the takeoff roll he
experienced control difficulties, so he jettisoned approximately
half of the retardant load in order to assist with directional
control of the aircraft. As the aircraft became airborne, it
pitched nose-up and rolled right. The right wing collided with a
sand dune and the aircraft cartwheeled onto the nearby beach,
coming to rest in shallow water. The pilot, who was the sole
occupant, egressed the aircraft uninjured. The aircraft was
destroyed. A total of 25 minutes had elapsed between the takeoff
attempt and the preceding landing.
The pilot assessed that while the aircraft was heavy at the
commencement of the takeoff roll, it was approximately 300 kg below
Maximum Takeoff Weight. Jettisoning of approximately half the fire
retardant load during the takeoff roll further reduced the takeoff
weight.
The Terminal Area Forecast current at the time of the accident
indicated a wind of 270 degrees at 15 kts. Recorded and observed
meteorological conditions indicated strong gusty north-westerly
winds.
The failure of the aircraft to become airborne while under
control was consistent with a takeoff attempt in a heavy aircraft
under the influence of strong tail and crosswind components.