The patient, aged in his 50s, suffered head, neck and ankle injuries when the buckle connecting the bucket on the excavator came off and the heavy machinery fell on him about noon on Wednesday.

"Being hit by a one-tonne excavator head on the side of his skull, he could have easily been dead," doctor Martin Londahl said.

"All I can say is I can't believe he got away that easy without critical injuries."

The man was taken to Mungindi Hospital in the Balonne Shire region, before the Toowoomba-based RACQ LifeFlight Rescue helicopter was dispatched to airlift him to Princess Alexandra Hospital in Brisbane, hundreds of kilometres away.

The helicopter, which had to refuel three times, arrived about 8pm.

"When I first saw him at the hospital, he was stable and awake, I was just amazed," Dr Londahl said.

LifeFlight pilot Russell Bennett said the mission was a co-ordinated effort with emergency services.

"The patient was stable throughout the trip but there was nothing we could do with the refuel but the medical staff is always concerned about the patient's wellbeing, especially this long trip," he said.

Mr Bennett said the lengthy trip would usually have been undertaken by plane, taking a surprising toll on medical staff.

"We had a continuing conversation to make sure we could take him to hospital as quickly and efficiently as possible," he said.

"We even had to swap with a night crew who finished the rest of the journey during the last stop for refuelling.

"The great outcome is all we could have hoped for ... the man was definitely lucky."