The operator did not place appropriate emphasis on ensuring the continuing airworthiness of the landing gear of its GA8 fleet, although being aware of:
There were no requirements in Aeropower procedures to provide any post-training supervision for powerline operations. What supervision was provided was ineffective in identifying that a modified stringing method was being used by the pilot.
Although required by the harness instrument commonly issued by the Civil Aviation Safety Authority, the operator did not appraise shooting crews of the risks of using only a harness for restraint during low-level flight.
A harness instrument, commonly issued by the Civil Aviation Safety Authority (CASA), stated that a harness could be used instead of a seatbelt for take-off and landing. Although not intended by CASA, this instrument was easily able to be misinterpreted as indicating that a seatbelt was not required to be used during take-off and landing.
Recurrency training and drills in aircraft emergencies were not required for reissue of an aerial platform shooting permission. Some shooters last conducted training about 20 years prior, during initial issue of their permissions.
The Director of National Parks did not actively manage the risk of the aerial culling task being conducted in the Kakadu National Park, or effectively supervise the operation. As a result, an increase in the number of crew, a change in helicopter type and change of helicopter operator all progressed without requisite risk management. This exposed crew to avoidable harm during low-level aerial shooting operations.
Although the Director of National Parks’ safe operating procedures required shooters and spotters to wear helmets during aerial culling tasks, helmets were not provided or used on a routine basis.
Annex 6 to the Convention of International Civil Aviation did not mandate the fitment of flight recorders for passenger-carrying aircraft under 5,700 kg. Consequently, the determination of factors that influenced this accident, and numerous other accidents have been hampered by a lack of recorded data pertaining to the flight. This has likely resulted in important safety issues not being identified, which may remain a hazard to current and future passenger carrying operations.
The ATSB is issuing the following recommendation:
There was no regulatory requirement from the Civil Aviation Safety Authority for piston‑engine aircraft to carry a carbon monoxide detector with an active warning to alert pilots to the presence of elevated levels of carbon monoxide in the cabin.
Australian civil aviation regulations did not mandate the fitment of flight recorders for passenger-carrying aircraft under 5,700 kg. Consequently, the determination of factors that influenced this accident, and other accidents have been hampered by a lack of recorded data pertaining to the flight. This has likely resulted in the non‑identification of safety issues, which continue to present a hazard to current and future passenger-carrying operations.
Response by the Civil Aviation Safety Authority
Although detectors were not required to be fitted to their aircraft, Sydney Seaplanes had no mechanism for monitoring the serviceability of the carbon monoxide detectors.
While the manufacturer's instructions for the zonal inspections detailed that installation blankets could be removed 'as necessary', they did not reference the insulation blanket installation procedure. This resulted in insulation blankets not being secured to the structure.
Pratt & Whitney Canada (PWC) PT6A-114A engines fitted with compressor turbine vane rings that have been repaired in accordance with the United States Federal Aviation Administration‑approved scheme STI 72-50-254 have a significantly increased likelihood of CMSX-6 compressor turbine blade fracture and subsequent failure of the engine compared to those engines fitted with PWC‑manufactured compressor turbine vane rings.
Virgin Australia Airlines did not require flight crew to confirm and verbalise external cues such as runway signs, markings, and lights to verify an aircraft’s position was correct prior to entering and lining up on the runway.
Virgin Australia Airlines did not require ATR flight crews to complete the Before take-off procedure prior to reporting ‘ready’ to air traffic control. This increased the risk of flight crews completing this procedure while entering the runway, diverting their attention to checklist items at a time when monitoring and verifying was critical.
The Robinson R44 pilot’s operating handbook low rotor RPM recovery procedure did not include reference to the minimum power airspeed for the helicopter as a consideration, which may assist a pilot to recover from a low rotor RPM condition. [Safety Issue]
Professional Helicopter Services did not have a calibration schedule for their passenger scales, which were under-reading. This increased the risk of their helicopters not achieving their expected take-off performance.
Airservices Australia’s configuration of the integrated tower automation suite (INTAS) at Perth Airport had resulted in a situation where controllers performing some combined roles had the INTAS aural and visual alerts inhibited at their workstation. As a result, controllers performing such combined roles would not receive a stop bar violation alert or runway incursion alert at their workstation.
The location and design of taxiway J2 at Perth Airport significantly increased the risk of a runway incursion on runway 06/24 for aircraft landing on runway 03. Taxiway J2 was published as the preferred exit taxiway for jet aircraft and, although mitigation controls were in place, they were not sufficient to effectively reduce the risk of a runway incursion.
Although Qantas provided detailed guidance to flight crews about the content of departure and approach briefings, it did not specifically require aerodrome hot spots to be briefed.