The asymmetric horizontal stabiliser design in the Robinson R22, R44 and R66 models significantly contributed to the uncommanded right roll rate during low‑G conditions and the risk of an in‑flight break‑up.
Response by Robinson Helicopter Company
The aircraft did not have the modifications recommended by CASA for Cessna 206 emergency exits, increasing the likelihood of impeded egress during emergency situations.
The Robinson Helicopter pilot’s operating handbook sections for operation in high winds or turbulence did not warn of the potential for turbulence-induced low‑G, and rapid right roll, particularly at high airspeed or provide guidance for appropriate control inputs in response to a turbulence-induced low‑G situation. This increased the risk of pilots encountering low‑G independent of control inputs, and an in‑flight break‑up.
Response by Robinson Helicopter Company
The operator’s pre-flight passenger briefing did not include the demonstration of, and pilots were not trained how to operate, the emergency exit via the cargo door with the flaps extended.
The Civil Aviation Safety Regulations Part 139 (Aerodromes) Manual of Standards 2019 section relating to the temporary closure of a taxiway at night did not:
The AGAIR aircraft VH-HPY pressurisation system could not reliably attain the required cabin altitude during flight due to a known, long-term, unresolved intermittent defect. AGAIR management personnel were aware of the defect and, through a combination of inaction, encouragement and, in some instances direct involvement, permitted the aircraft to continue operations at an excessive cabin altitude.
The Airservices Australia hypoxic pilot emergency checklist did not contain guidance on ceasing the emergency response. This increased the risk that a controller may inappropriately downgrade the emergency response during a developing hypoxic scenario.
AGAIR Gulfstream 690 and 695 aircraft were operated with known defects without being recorded on the aircrafts’ maintenance release, likely as a routine practice. For VH-HPY, the absence of documented historical information limited the ability to assess the operational impact of the pressurisation defect and the effectiveness of maintenance rectification activities.
AGAIR management exercised ineffective operational control over the line scanning activities. As a result, the ongoing intermittent pressurisation defect was not formally recorded, the issues with the aircraft were not communicated to the AGAIR safety manager, and the hazardous practice of operating the aircraft at a cabin altitude that required the use of supplemental oxygen, without access to a suitable oxygen supply, was allowed to continue.
Batik Air's change management processes were not effective at fully identifying and mitigating the risks associated with the commencement of the Denpasar to Canberra route.
Batik Air did not ensure that flight crew completed all common traffic advisory frequency (CTAF) training prior to them operating flights into Australia where the use of these procedures could be required.
The Civil Aviation Safety Authority guidance for pilots using non-controlled aerodromes did not clearly define the active runway. The guidance did not provide practical advice to pilots using a secondary runway, and in some situations, it was contrary to existing regulations.
The Caboolture Gliding Club had a regular practice of using runway 06 for some flights, including during periods of light traffic on runway 11/29. This increased the risk of collision as Caboolture was a non-controlled aerodrome relying on alerted see-and-avoid principles, and there was a stand of trees obstructing pilots' vision of intersecting runways.
The Caboolture Aero Club did not effectively manage or inform pilots of the risk presented by trees and buildings around the airfield that prevented pilots from being able to see aircraft on intersecting runways and approach paths.
De Havilland Aircraft of Canada Limited did not publish any guidance to operators of Dash 8 aircraft on the transmission and reception performance limitations of VHF COM 2 radios for ground-based communications.
Due to topography and buildings at Mildura Airport, aircraft are not directly visible to each other on the threshold of runways 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.
The QantasLink radio procedure required Dash 8 flight crews to use the VHF COM 2 radio to broadcast and receive on local frequencies during operations at non-controlled aerodromes. This reduced the ground-based radio transmission and reception strength, and therefore reduced the likelihood of other aircraft receiving calls in some circumstances.
Qantas did not have a procedure to assess cabin crew fitness after a serious injury. This increased the risk that a crew member could continue to operate while being unfit for duty.
Esso Australia did not have a procedure for a helicopter recovery from inadvertent IMC during hoist operations or recovery procedures for EGPWS alerts or advisories.
The decision height for assessing whether an aircraft met Wave Air’s stabilised approach criteria was too low.
