A culture existed within the engine manufacturer's Hucknall facility where it was considered acceptable to not declare what manufacturing personnel determined to be minor non-conformances in manufactured components.
The procedure for the first article inspection process contained ambiguities that resulted in an interpretation whereby the use of the manufacturing stage drawings was deemed to be acceptable.
The engine manufacturer did not require its manufacturing engineers to consult with the design engineers to ensure that design intent would be maintained when introducing manufacturing datums.
Numerous other engines within the Trent 900 fleet were also found to contain a critical reduction in the oil feed stub pipe wall thickness.
The engine manufacturer's process for retrospective concessions did not specify when in the process the Chief Engineer and Business Quality Director approvals were to be obtained. Having them as the final approval in the process resulted in an increased probability that the fleet-wide risk assessment would not occur.
The calculation method in the aircraft manufacturer’s landing distance performance application was overly conservative and this could prevent the calculation of a valid landing distance at weights below the maximum landing weight with multiple system failures.
The manufacturer’s classification, relating to the criticality of failure, of the HP/IP bearing support assembly was inappropriate for the effects of a fire within the buffer space and hence, the requirement for an appropriate level of process control was not communicated to the manufacturing staff.
The engine manufacturer’s group quality procedures did not provide any guidance on how manufacturing personnel were to determine the significance of a non-conformance, from a quality assurance perspective.
The helicopter’s lighting set-up did not allow independent control of the searchlights by the pilot using the switches on the flight controls, as required by the operations manual and Civil Aviation Order 29.11, and increased the risk of loss of hover reference and distraction in the case of a single light failure or switch mis‑selection by a pilot.
The increased capability of helicopters and rescue winches enabled the conduct of complex winch rescues beyond the current level of winch training and procedural support associated with the traditional special casualty access team clinical access role, leading to an increased risk that hazards associated with complex rescues were not identified.
Ambulance rescue crewmen did not conduct any night winching recency training, resulting in an increased risk of unfamiliarity with night winching procedures and their associated hazards.
The accepted use of procedural adaptation by special casualty access team paramedics, and the past success of rescues that involved adapted techniques, probably led to the retrieval procedure that was used on the night.
A significant number of R44 helicopters, including VH-COK, were not fitted with bladder-type fuel tanks and the other modifications detailed in the manufacturer's Service Bulletin, SB-78 to improve resistance to post?impact fuel leaks and fire.
Accidents involving Robinson R44 helicopters without bladder-type tanks fitted result in a significantly higher proportion of post-impact fires than for other similar helicopter types. In addition, the existing Australian regulatory arrangements were not sufficient to ensure all R44 operators and owners complied with the manufacturer's Service Bulletin SB-78B and fitted these tanks to improve resistance to post-impact fuel leaks.
There was no requirement for a systematic risk assessment to be conducted and documented when the planned amount of training for a controller was reduced.
Many DHC-8 pilots were not made aware of the sound of the beta warning horn during their training.
A significant number of DHC-8-100, -200 and -300 series aircraft did not have a means of preventing inadvertent or intentional movement of power levers below the flight idle gate in flight, or a means to prevent such movement resulting in a loss of propeller speed control.
The first 39 manufactured DHC-8-100 aircraft had a design problem such that, if the friction control was wound to the full out (friction off) position, the flight idle gate was ineffective in reducing the likelihood of pilots inadvertently moving the power levers below flight idle in flight.
The Cairns air traffic control procedures on the management of missed approaches and the management of successive arriving aircraft were unclear in intent and function, increasing the risk of their incorrect application.
The Cairns air traffic control procedures that defined a minimum spacing of 5 NM to be established when there were no departures (when the cloud base is less than 1,000 ft and/or visibility is less than 2,000 m) were inadequate to assure separation during a missed approach event and may result in future loss of separation occurrences.
