TWEED residents may have looked up with surprise earlier today when a large military aircraft passed overhead.

An Australian Air Force Boeing C-17A Globemaster did a fly over of Gold Coast Airport at 3.20pm today.

An airport spokeswoman said the aircraft flew over Tweed/Coolangatta on a training exercise but did not land.

A Defence spokesperson said A Royal Australian Air Force C-17A Globemaster was conducting routine training flights to and from the RAAF Base at Amberley today.

"The flight path includes the Gold Coast, which is regularly used by RAAF Base Amberley aircraft for training," the spokesperson said.

"The support of Gold Coast residents is appreciated for this vital training.

"The Air Force's ability to respond quickly is a result of high training standards. No one can predict when or where RAAF will need to respond, so our pilots and crews have experience in a range of environments.

"This includes day and night flying, high and low altitude flying (below 500 feet or 150 metres)."

According to the air force, the Globemaster has three times the carrying capacity of the C-130 Hercules.

The aircraft is 53m long with a wingspan of 51.7m.

Based at Amberley, the Globemaster can accommodate up to 134 troops and has a range of 4500km.