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.
Microflite had not published an inadvertent instrument meteorological conditions (IIMC) recovery procedure for their day visual flight rules pilots and their IIMC recovery training was not mandatory. The provision of this procedure and training would have reduced the risk of a loss of attitude control following an IIMC encounter.
The Microflite Operator Proficiency Checks did not include a mandatory instrument flight component for their day visual flight rules pilots. This would have reduced the risk of a loss of control event following an inadvertent instrument meteorological conditions encounter.
The operator's hazard and risk register, which formed part of the organisation's safety management system, did not identify inadvertent entry into instrument meteorological conditions as a hazard, which reduced the ability of the organisation to effectively manage the related risk.
The training provider, contracted by the operator to conduct Boeing 737 conversion training, was training pilots to flare at 30 ft rather than the manufacturer’s requirement of 20 ft. This increased the risk of unstable and/or hard landings.
Helibrook’s approved safety management system was not being used to systematically identify and manage operational hazards. As a result, risks associated with conducting human external cargo operations such as carriage of the egg collector above a survivable fall height were not adequately addressed.
Response by Helibrook
The Civil Aviation Safety Authority (CASA) did not have an effective process for assuring an authorisation would be unlikely to have an adverse effect on safety. As a result, CASA delegates did not use the available structured risk management process to identify and assess the risks, ensure appropriate and adequate mitigations were included as conditions of the approval, or assess the effects of changes on the overall risk.
The design of the horizontal stabiliser bungs did not consider aspects that would ensure the identification of an installed bung, or the safe operation of the aircraft if the bungs were not removed prior to flight.
There were no formal procedures for the storage and accountability of horizontal stabiliser bungs after they were removed from the aircraft.
Airservices Australia’s compromised separation recovery training for Sydney tower controllers did not include scenarios involving aircraft below the minimum vector altitude at night.
Airservices Australia did not have procedural controls to separate aircraft concurrently carrying out the MARUB SIX standard instrument departure and a missed approach from runway 34R at Sydney Airport while below the minimum vector altitude at night.
Although Airservices Australia applied operational risk assessments to high-level threats, it did not formally assess and manage the risk of specific threat scenarios. As a likely result, Airservices did not formally identify and risk manage the threat of separate aircraft concurrently carrying out the MARUB SIX standard instrument departure and a missed approach from runway 34R at Sydney Airport, even though it had been a known issue among controllers generally.
The Airservices Australia MARUB SIX standard instrument departure and the missed approach procedure for runway 34R directed aircraft onto outbound tracks that did not sufficiently assure separation between aircraft following the procedures concurrently.
