Captain Danniel Lyon, Lieutenant Maxwell Nugent, Warrant Officer Class Two Joseph Laycock and Corporal Alexander Naggs were killed when their chopper crashed off the north Queensland coast in July 2023 during multinational exercises.
The disaster led the Australian Defence Force to call time on the Taipans, their service already tarnished with fleet-wide groundings and serious incidents and the government withdrew them from service a decade earlier than scheduled.
Hearings for the inquiry into the crash resumed on Monday.
Four serviceman died in the crash in north Queensland in July 2023. (HANDOUT/DEPARTMENT OF DEFENCE)
Captain Andrew Balaam, a MRH-90 pilot posted to the School of Army Aviation, said a test of the latest software upgrade V5.10 for the TopOwl helmet worn by the pilots found an "unacceptable" risk.
But the captain said he was happy to use the helmet because the report deeming the upgrade "unacceptable" appeared to be "a bit of an outlier" as it had passed tests with the original equipment manufacturer and had been used by European militaries.
"I was gonna have to fly that thing for real at night over water in a degraded visual environment, I was happy to do that," he said.
"As indeed were the other 11 pilots ... we were not turkeys voting for Christmas, we were going to have to use it.
"So I was happy to use it."
He was responding to a question about allegations aired during a 60 Minutes investigation the Australian Defence Force ignored warnings in 2020 about the safety of the upgrade, which could lead to deaths.
"I was aware that a previous test ... had been conducted where they had stated that version 5.10 was unacceptable," Captain Balaam told the inquiry.
"That was their conclusion."
But he defended the update and said he understood how the evaluation would have reached that view looking at it in isolation.
"If you took a slightly broader view and looked at what 5.10 was replacing and the advantages that it brought, on a balance of risk, it was probably wise to proceed, because the issues that it was resolving were equally as challenging," Captain Balaam said.
Asked if the pros outweighed the cons, he replied "absolutely".
The Taipans are set to be replaced with Black Hawks imported from the United States.
