'The life we never chose': Families of Taipan crash victims demand answers at inquiry

Corruption claims and allegations of fabricated evidence have dominated a day of hearings as part of a Senate inquiry into a fatal army helicopter crash that claimed the lives of four men.

Next month will mark three years since the tragedy, which claimed the lives of Captain Danniel Lyon, Lieutenant Maxwell Nugent, Warrant Officer Joseph 'Phillip' Laycock and Corporal Alexander Naggs.

The four men were on board an MRH-90 Taipan helicopter during a Talisman Sabre training exercise in north Queensland's Whitsunday region when their aircraft suddenly ditched and plummeted into the ocean while flying in formation.

The inquiry is before the Senate's Legal and Constitutional Affairs References Committee and was established after One Nation Senator Malcolm Roberts successfully moved a vote.

It marks the fifth stream of investigation into the crash — including an independent inquiry by the Inspector-General of the Australian Defence Force (IGADF) which is soon to be handed down — but family members of the men who died said despite repeated probes, no one has been held accountable.

The widow of Captain Lyon, who was the pilot of the aircraft, pleaded with the senate; demanding answers and accountability.

Caitland Lyon told the inquiry the couple's son Noah still sleeps on the pillow of his father every night, and their daughter Lily "cries, begging for Daddy to come back from heaven."

"She has lived far more days crying for him than she ever had laughing with him,"

she said.

"This is our life now. The life we never chose."

A key part of the probe surrounds the reason why Commonwealth prosecutors decided not to pursue Defence criminally last year, over alleged breaches to workplace health and safety laws.

The ABC has previously reported the workplace safety investigative and compliance body, Comcare, identified two alleged breaches of laws, relating to fatigue and controversial technology the two pilots were wearing the night of the crash.

Last year, the Commonwealth Director of Public Prosecutions (CDPP) opted not to lay charges, citing a lack of evidence and no reasonable prospects of securing a conviction.

Problems 'paperworked over', former pilots say

Two former Taipan test pilots, who gave evidence to the IGADF inquiry, were the first to appear at today's Senate hearing.

Retired Major Ian Wilson and retired Major David Lamb formerly worked at army's aviation testing organisation, AATES.

In testing of a software upgrade for pilot's night vision goggles — TopOwl 5.10 — the technology was deemed to pose an unacceptable risk to safety as it would occasionally display incorrect or ambiguous readings.

It was pushed into service, despite Major Wilson voicing fears someone would die if it was allowed to be used.

"Was this incident the exact incident you feared, because of the problems you saw in testing?" Senator David Shoebridge asked Major Wilson.

"It's almost to the word," he replied.

Major Wilson told the inquiry the problems were "paperworked over".

The Defence Flight Safety Bureau (DFSB) investigation into the downing of the Taipan helicopter determined it was unlikely to have contributed to the crash.

Major Wilson told the Senate the report was unreliable, flawed and the DFSB investigation had "manipulated" or "fabricated" evidence and had been "corrupted".

"There was an obvious and well-known conflict of interest within the investigation team,"

Major Wilson said.

The inquiry heard one of the experts who provided evidence to the DFSB may be the same person who signed off on a memo downgrading the risks of the TopOwl 5.10 technology.

Senator David Shoebridge grilled DFSB director, Group Captain David Smith over this "perceived conflict of interest".

"Were you aware [of the conflict of interest] and how did you manage it?" Senator Shoebridge asked.

"That conflict of interest was not a subject of our report sir," Group Captain Smith replied.

"Well perhaps it should have been before you relied on [that person] and his evidence," Senator Shoebridge said.

"Without his operational evaluation report … [the aircraft] wouldn't have been in the air.

"I am astounded that you are not able to address this conflict of interest here."

Major Wilson raised concerns that the report could have been used by the CDPP.

"The report … I understand, was tendered to the criminal investigation conducted by Comcare and may have affected the decision by the CDPP not the prosecute," he said.

Director of Public Prosecutions, Raelene Sharp KC, confirmed the DFSB report was "made available" to the CDPP.

Comcare CEO Colin Radford said he was not aware of any conflicts of interest, corruption or fabricated evidence in the report, but took on notice a question as to whether independent evidence was sought.

Lieutenant Maxwell Nugent's mother, Marianna Nugent also raised the point in her written submission.

"I remain concerned about the independence of [the DFSB's report] if an investigator involved in the crash investigation also had prior involvement in the recommendation to introduce the TopOwl software upgrade despite … advice not to," she wrote.

In her oral statement to the inquiry, Ms Lyon implored the Senate to probe whether the CDPP's decision relied on the "flawed and compromised" report.

"I am not here for punishment. I am here for accountability, and to make sure this never happens again,"

she said.

The CDPP has seemingly left the door open to future prosecutions, stating if it appeared from the outcome of the IGADF inquiry or a coronial inquest that an offence had occurred, it could re-evaluate a new brief of evidence from Comcare.

"This may result in a decision to prosecute the [Department of Defence] for offences against the WHS Act in relation to the incident," the CDPP said.

Before the inquiry came to a close, the family members of the four men made an emotional plea to the Senate for accountability.

"Those warnings [about TopOwl 5.10] were ignored or worked around, that is a fundamental failure of work health and safety," Daniel Nugent, the father of Lieutenant Nugent told the inquiry.

Mr Nugent said his son gave everything to Defence, and the organisation owed it to him to provide him with the safest equipment, honesty and to act on warnings.

"That did not happen. They failed him and they know it."

Lieutenant Nugent's partner, Chadine Whyte called for Defence to "lead with the same integrity" her partner did.

"Anything less is an insult to his life and memory, and to those who remain in service," she said.

"Please do for them what was not done for him."

The report from the Senate inquiry is due in September.