Australia's entire fleet of Super Hornets and Growlers will be grounded after two pilots were forced to eject before a crash at Queensland's Amberley air base.

The pair were taking off in an FA-18F Super Hornet fighter as a part of a training exercise when the incident occurred around 2.30pm on Tuesday.

It's understood there was a problem with the jet's nose wheel, which triggered an automatic ejection system.

The Federal Government has now grounded the jets "out of an abundance of caution" as investigators search for answers over what led to the accident.

"Defence can confirm that an incident involving an Air Force F/A-18F Super Hornet has occurred during takeoff at RAAF base Amberley," a ­Defence spokesperson said in a statement yesterday.

"Defence's first priority is the safety of personnel at RAAF base Amberley. Defence will provide more information once the immediate actions associated with the incident are completed.

"The aircrew ejected and are safe.

"No other personnel were involved in the incident.

"The cause of the incident is not known at this time and will be subject to investigation," it said.

Originally published as Jet fleet grounded after pilots forced to eject before Qld crash