But the operator says the crash occurred in a compliant organisation that exceeded regulatory expectations.
Two Sea World helicopters collided above the Gold Coast Broadwater in January 2023, during the peak of the busy summer holiday season.
A litany of factors led to the crash, including limited visibility, failed radio transmissions and a lack of safety protocols, the final report from the Australian Transport Safety Bureau revealed.
The operator had changed the helipad locations nine months before the crash which meant there was a possible crash point.
The collision point is where the two helicopters' flight paths risked intersecting during simultaneous flights.
This meant the operations were an "accident waiting to happen", aviation expert Peter Cartner told AAP.
"Anyone who had spent five minutes considering the risks would have seen them and would have got a system to prevent the collision point," the director of Carter Capner Law said.
"All of the other issues could have been remedied ... that's what made it an accident waiting to happen."
One of the most outstanding issues was an antenna failure in the departing helicopter's radio that existed for days, the ATSB found.
The departing pilot tried to make a call to alert the other helicopter that they were leaving but it was never delivered to the other aircraft due to the fault.
However, Mr Cartner said the radio issues were not as crucial as the known collision point or the fact the pilots relied on a see-and-avoid strategy in a high intensity and congested airspace.
The national regulator, the Civil Aviation Safety Authority (CASA), should have required better standards from Sea World Helicopters due to the unique nature of the operation with hundreds of flights a day within minutes of each other in a congested airspace, Mr Cartner added.
"I think the ATSB downplayed the failings of CASA," he said.
Sea World Helicopters reaffirmed its commitment to the safety of its passengers and staff in the wake of the safety bureau report.
"The 2023 accident was a devastating tragedy, and our deepest sympathies rest with the victims, their families, and our staff who have been profoundly impacted by it," the operator said in a statement.
It thanked the safety bureau for its investigation but said the accident occurred within a "compliant and professionally managed organisation, which exceeded the minimum regulatory requirements of the general aviation sector".
"Our company maintains robust safety systems, dedicated support staff and rigorous oversight protocols to uphold the highest standards of aviation safety," it said.
It said it acknowledged the ATSB's specific recommendations and would respond within the allocated timeframe.
Pilot Ashley Jenkinson, 40, British couple Ron and Diane Hughes, 65 and 57, and Sydney mother Vanessa Tadros, 36, died in the crash and nine others were injured.
Claims on behalf of victims and witnesses of the crash have been lodged in the Brisbane Supreme Court, with the report's findings expected to influence future proceedings.
Shine Lawyers and Carter Capner are representing those affected who suffered serious injuries, lifelong scarring and life-changing anguish with claims filed up to $925,000 per person.
Safety bureau commissioner Angus Mitchell flagged on Wednesday a coronial inquest into the deaths was likely to take place.
Mr Cartner said it would be a whole new inquiry under fresh eyes using the safety bureau report to inform the investigation with the possibility of future criminal proceedings or further civil action.
