Sea World helicopter crash video trends now

It was another perfect sunny day in paradise as the Sea World helicopter lifted off from the theme park's helipad at Southport on Queensland's Gold Coast.

There was a slight breeze blowing but nothing to concern anyone as British-born pilot Ash Jenkinson, 40, balanced the chopper's sensitive controls to gently lift off just before 2pm on Monday.

On board with him were six passengers - British holidaymakers Ron Hughes, 65 and his wife Diane, 57, and Sydney mother Vanessa Tadros, 36, with her son Nicholas, 10, plus Winnie De Silva, 33, and her son Leon, 9, from Geelong, Victoria.

A few hundred metres away, a second Sea World helicopter with a pilot and five passengers on board flew above the rising aircraft, heading towards it at a 90 degree angle.

Why neither pilot saw the other or took evasive action will be the main focus of the air crash investigation now underway.

But just 20 seconds after the lower aircraft took off, the two Eurocopter EC130s collided around 200m off the ground.

As the first chopper gained altitude, it smashed into the second helicopter which appeared to be descending.

The churning rotors of the first helicopter ripped into the cabin of the second one, shattering its glass cockpit just centimetres from the pilot and passengers inside.

Eyewitnesses said they saw a terrifying cloud of broken glass and debris explode as the two aircraft ploughed into each other in mid-air. 

The devastating force of the collision ripped the rotor unit and gearbox from the lower chopper, immediately sending it hopelessly tumbling out of control.

It spun upside down and plummeted to the ground below, smashing into a sandbar, killing the pilot, Mr and Mrs Hughes ands Ms Tadros on impact.

Incredibly though, the pilot of the second aircraft managed to maintain control of his chopper despite the extensive damage to its front fuselage.

A Sea World visitor told 7 News they'd seen one of the aircraft 'in a tailspin with the cockpit windows falling away after impact'. 

Pictures from the scene reveal the second helicopter's entire cockpit was smashed open by the other chopper's rotor blades, with the glass fragments and high-speed rotor blades causing unknown injuries to those inside.

But the pilot somehow managed to keep the second chopper airborne long enough to quickly and safely crash land on the sandbar near the first helicopter. 

Air crash investigators admitted the death toll could have been even higher if not for the quick action of the pilot. 

'We could have had a far worse situation here and the fact that that one helicopters managed to land has been quite remarkable,' said Air Transport Safety Bureau Chief Commissioner Angus Mitchell.

'We are very fortunate that we're not standing here with far more deaths.

'The forces involved in coming down, not only in the actual collision which are substantial, but in the uncontrolled fall once it's lost its main rotor, are considerable.

'The second helicopter has landed on the sandbar and that has obviously led to the stage where we are not seeing more fatalities here.'

Footage of the first moments after the crash showed a flotilla of private boats rushing towards the crash site to help, including an amphibious bus. 

Police and ambulance services arrived shortly afterwards with two air ambulance helicopters also touching down on the sandbar. 

The first to the crash site were faced with 'very, very confronting' scenes, said acting Inspector Gary Worrell on Tuesday.

'We had private vessels taking people across to the island to offer support to the victims,' he said.

'They did their very best with CPR until the emergency services got there.

'Unfortunately though, we did have those four that were deceased but there were three being worked on significantly at the scene until they got transported by the air ambulance.'