The air force breached international aviation standards by placing dangerous chemical canisters on an Air New Zealand passenger flight - and then told no one about it, according to a Civil Aviation Authority report.
A string of communication failures meant the 2009 incident which "seriously endangered" the lives of up to 379 passengers travelling to Canada was never revealed outside the Royal New Zealand Air Force until the Herald revealed it last week.
An internal air force report obtained by the Herald said the "illegal" act "seriously endangered" the lives of those on the Air NZ flight and included the incident among safety failures leading up to the fatal Anzac Day crash in 2010 that killed three servicemen.
The CAA report is the first feedback from three government inquiries into issues surrounding air force safety. Inquiries into safety changes and the failure to investigate health and safety breaches are also under way.
CAA safety investigation manager Graeme Harris said the interim report - released after a week's investigation - showed "significant failings within the RNZAF".
He said administrative and communication errors led to the dangerous cargo being carried even though it was banned from passenger aircraft. The Passenger Service Units (PSUs) contained oxygen generating canisters with no safety pin.
When activated, they can heat up to 260C and cause fires on board - like the one that brought down a ValuJet flight in 1996, killing 110 people.
The report says further investigation is needed to check how effective air force measures are to prevent recurrence of a similar event.
An internal air force inquiry had highlighted the "gravity of failings" regarding international aviation standards and the need to alert the authorities. The CAA found "this was never done".
Instead, the CAA found the air force failed to tell all those who should have been informed about the incident. Those bodies were the Transport Accident Investigation Commission, Air NZ, the freight-handling company and the CAA.
The CAA found there was a "misunderstanding" between TAIC and the air force which led to the transport agency being misinformed and told "the PSU had not actually been loaded or carried on the aircraft".
It also found Air NZ and the cargo handler were aware of carrying dangerous goods - but did not realise they were canisters banned from passenger aircraft.
The CAA found the cargo was incorrectly listed as "life-saving appliances self-inflating" rather than the banned "oxygen generator, chemical".
It found the air force had carried out its own investigation and admitted it had been at fault for not putting safety pins into the canisters and for the incorrect labelling. The air force inquiry led to 22 safety recommendations, of which 19 had been put in place.
The Herald investigation into air force safety found that a report into the Anzac Day 2010 crash had reviewed previous safety recommendations, finding that only 47 per cent had been followed through in 10 years. The paper began investigating after former Squadron Leader Rob Stockley spoke out about unheeded safety warnings before the fatal Anzac Day crash.
Last night he said the air force was trying to do too much with too little. "They're sacrificing excellence for reputation when they should let excellence be their reputation."