An army pilot has described a "daunting" near miss he experienced in a Taipan helicopter, three years before four men died in the same aircraft off the Queensland coast.
An independent inquiry is examining the circumstances that led to the catastrophic MRH-90 Taipan crash in July 2023, near Lindeman Island, which claimed the lives of four Defence personnel.
On Tuesday, MRH-90 pilot Major Michael Gallatly told the inquiry he had been flying a Taipan helicopter with late Captain Danniel Lyon off the NSW coast, when the aircraft suddenly lost altitude during a turn.
Major Gallatly said he quickly recovered altitude by switching auto pilot off, but that the experience left him rattled.
"The system couldn't perform at the level it was required to," Major Gallatly said.
It's the first time the inquiry, which is sitting in Brisbane, has heard from a Taipan pilot.
Major Gallatly criticised the complexity of the MRH-90 aircrafts, which he said often caused confusion for several pilots.
He recounted a time when another pilot had accidentally switched the engine off when attempting to turn on a landing light, as the buttons were closely located in the cockpit.
"It's a complex aircraft, if you fly it infrequently the complex system can be quite overwhelming," he said.
The inquiry also heard a lack of senior pilots, not enough training aircraft, and maintenance issues meant pilots often felt unprepared when flying.
"At no stage did I feel confident that I could keep everyone safe in that aircraft," Major Gallatly said.
Earlier this year, the inquiry heard crew members raised concerns about fatigue management and safety issues in the months leading up to the incident.
Major Gallatly said crews often worked long overnight hours during training operations.
"Fatigue was one of the bigger issues … it took a lot from people," he said.
Earlier, former judge Margaret McMurdo — who is overseeing the inquiry — denied an application from Australian Defence Force (ADF) lawyers to remove two key witnesses from the hearing.
In an 11th hour attempt, the solicitors argued the witnesses' inclusion could potentially lead to the ADF being blamed for the crash.
"We seek to delay the investigation of those matters if they are capable of suggesting one of the deceased, or someone else, may have directly contributed to the tragedy," Andrew Berger SC said.
The two witnesses, known as D15 and D20, were frequently mentioned in the second phase of the hearings in May.
D20 is understood to be a fellow troop commander that worked alongside Captain Lyon.
Caitland Lyon, the captain's widow, previously told the inquiry that D20 was sent home by a troop commander during a training exercise after they raised concerns about fatigue issues.
ADF lawyers argued the witnesses should only give evidence once a report from the Defence Flight Safety Bureau (DFSB) was released.
But Judge McMurdo questioned why the report, which was initially due in July, had been further delayed by six months.
"Delay is well known and well documented as the most distressing thing for people experiencing trauma," she said.
The inquiry will continue until Friday.