The Coulson Aviation practice of recalculating the target retardant drop airspeed after a partial drop reduced the post-drop stall speed and energy‑height safety margins.
Likely due to an underlying lack of resources within Airservices Australia, there was an over‑reliance on tactical changes to manage the roster. As a result, cumulative fatigue was not being effectively managed strategically and an over‑reliance on tactical principles did not identify or manage fatigue risks arising from the work schedule.
Although Airservices Australia’s fatigue assessment and control tool (FACT) had the means of identifying situational factors that influenced fatigue, it had limited effectiveness as supervisors were not identifying low workload as a fatigue hazard.
Likely due to an underlying lack of resources within Airservices Australia, there was an over‑reliance on tactical changes to manage the roster. As a result, cumulative fatigue was not being effectively managed strategically and an over‑reliance on tactical principles did not identify or manage fatigue risks arising from the work schedule.
Fly Oz's asymmetric training procedure involved failing one engine using the mixture control without confirmation the engine was subsequently restarted, rather than reducing throttle to simulate zero thrust in accordance with the Beechcraft E55 Airplane Flight Manual. This increased the risk of undetected asymmetric operation during descent and landing and the associated loss of control.
Due to topography and buildings at Mildura Airport, aircraft are not directly visible to each other on the threshold of runway 09, 27 and 36. The lack of a requirement for mandatory rolling calls increased the risk of aircraft not being aware of each other immediately prior to take-off.
Swissport did not ensure that the implemented training and audits for Link Airways Saab 340B dispatches incorporated all of the elements required in its Ground operations manual for pre‑departure walk-arounds.
Guidance provided by Link Airways for training of Swissport dispatch coordinators did not explain the appearance, function and importance of the propeller straps.
The propeller strap did not have a high-visibility streamer attached, and Link Airways did not effectively manage the condition of propeller straps for its Saab 340B fleet. This affected the visibility of the straps during ground operations.
On one-third of the Link Airways Saab 340B flights for which video surveillance was examined, including the occurrence flight, the flight crews did not fit the strap extension between the propeller strap and the airstairs. As the cabin door could not be closed with the strap extension in place, its correct fitment would almost certainly prevent a flight from proceeding with a propeller strap fitted.
An earlier version of the helicopter operations checklist was used by the crew of the Tai Keystone. That checklist did not include a requirement, present in the version current at the time of the incident, to remove handrails or stanchions from the helicopter landing site.
Although National Jet Systems contained procedures for recognition and management of pilot incapacitation, the associated training did not include the identification and response to subtle physical or cognitive incapacitation.
National Jet Systems’ cabin air quality events procedure focused on the recording/reporting of odours, post-flight care of crew and maintenance actions. However, it did not consider the possible application of the smoke/fumes procedure, or incapacitation procedure. As a result, there was an increased risk of flight crew being adversely affected by such an event during a critical stage of flight.
Although suitable for use in most situations, the streamers attached to the pitot probe covers supplied and used for A350 operations by Heston MRO at Brisbane Airport provided limited conspicuity due to their overall length, position above eye height, and limited movement in wind. This reduced the likelihood of incidental detection of the covers, which is important during turnarounds.
The majority of Singapore Airlines flight crews (observed around the time of the incident) did not fully complete the required pre-flight walk-around inspections.
Heston MRO did not track the work-related hours of personnel with dual management and operational roles (including the licenced aircraft maintenance engineer) for fatigue calculation purposes. Therefore, there was an increased risk of a fatigue related incident involving those personnel.
Heston MRO had not yet implemented a previously proposed and accepted method to account for tooling and equipment (such as pitot probe covers) prior to aircraft pushback.
The Civil Aviation Safety Authority's Part 133 (air transport - rotorcraft) exposition requirements did not adequately address the risk to passenger safety from a visual flight rules inadvertent instrument meteorological conditions event.
CASA response
On 21 November 2023, the Civil Aviation Safety Authority advised the ATSB that:
The Microflite air transport operations risk assessment for poor weather conditions did not consider the risk controls required for inadvertent instrument meteorological conditions. Rather, it relied on their pilots using the actual or forecast conditions to cancel their operations to manage the threat of poor weather.
Microflite did not provide, nor require, their pilots to complete a pre-flight risk assessment for their taskings. A pre-flight risk assessment would have provided pre‑defined criteria to ensure consistent and objective decision-making and reduced the risk of them selecting an inappropriate route.
