Air crash investigators don't expect a final verdict on what caused the deadly Sea World helicopter collision until the second half of next year.
Both police and the Australian Transport Safety Bureau are examining the crash, which killed four people on the Gold Coast on Monday afternoon and left three more fighting for life.
They've repeatedly warned it could be a lengthy investigation but the ATSB has now given its longest timeframe yet, pegging the third quarter of 2024 as the "anticipated completion" date.
The bureau's website previously gave an estimate a full year earlier, but a spokesperson said this was an automated figure.
They said after speaking with investigators, the 18-month timeframe was more realistic given the significance of the crash.
Investigators have been combing through footage of the crash and speaking to witnesses but it's still unclear what caused the Sea World Helicopters aircraft to collide, killing pilot Ashley Jenkinson, Sydney woman Vanessa Tadros and British couple Ron and Diane Hughes.
Vanessa's son, Nicholas, is still fighting for life in hospital while Leon De Silva, the nine-year-old boy from Geelong West, has woken from his coma and his mother, Winnie, is also doing better.
They were all travelling in the same helicopter that plummeted to the ground after impact, while pilot Michael James managed to land the other aircraft, saving everyone on board.
Footage taken from inside the cockpit shows a passenger tapping James on the shoulder in an apparent attempt to warn him moments before impact.
The two New Zealand couples on board James' helicopter, thanked their "hero" pilot for landing safely, while expressing their "deepest sympathies and sincere condolences" to those who died or were severely injured.
Jenkinson was remembered as "a first-class pilot, a first-class man and a wonderful father".
Vanessa's husband, Simon Tadros, described the Glenmore Park mum as "most loving, kind-hearted caring angel" and called on people to pray for Nicholas's recovery.
A vigil is planned for Sunday, January 15, on the Gold Coast.
Sea World Helicopters owner John Orr-Campbell said his team continued to offer its "deepest condolences, support and counselling" to the passengers of both aircraft.