Defence has grounded 35 Australian warplanes after two crew members were forced to eject from a $75 million fighter jet during an aborted take-off at an air base in Queensland on Tuesday.

Investigators were heading to RAAF Base Amberley outside Brisbane to figure out what led to the incident, which has caused damage to the F/A-18F Super Hornet.

Defence Minister Linda Reynolds confirmed the two pilots were safe, but said the entire RAAF fleet of Super Hornet and Growler jet fighters was being grounded out of an “abundance of caution”.

The Chief of Air Force, Air Marshal Mel Hupfeld, would not put a timeframe on the investigation, or how long the jet fighters would be out of action.

“We’ve got the fleet of 24 Super Hornets, and 11 EA-18G Growlers … we’ve ceased our flying operations while we review the circumstances of this incident,” he said in Canberra.

“This is sophisticated machinery. I’ve got thousands of [flying] hours on the classic Hornet, and I’m not going to surmise on the cause of this incident.

“There’s many things that we pull together to operate an aeroplane like this, this needs to undergo a suitable level of investigation to get the right answers so that we can provide the right solutions.”

Air Marshal Hupfeld said any findings would also be shared with other countries that operate the same aircraft.

On Tuesday, witnesses told the ABC they saw the pilots eject from the Super Hornet as it was about to take off.

Photos from the scene suggested the plane had a collapsed nosewheel, or the nosewheel was in a drain.

The Super Hornet had the same engine type as the RAAF Growler that “destroyed itself” during an attempted take-off in 2018.

Australia’s Super Hornet fleet is only a decade old, and entered operation in December 2012.

The Chief of Air Force and the Defence Minister were quizzed about the incident at an event spruiking the latest stages of development of the F-35 Joint Strike Fighter.

Australia is spending $17 billion to acquire the F-35, and will eventually have a fleet of 72.

-ABC