The Boeing 767 carrying 161 passengers was en route from Darwin to Brisbane when the decision was made to divert the aircraft to Mount Isa Airport.

Flight QF 825 landed without incident but it took emergency crew more than an hour to evacuate passengers from the grounded plane.

Passenger Cliff Watkins from Darwin said passengers were informed they would have to remain on board the aircraft because there were no stairs tall enough to reach the cabin door at the regional airport.

"They had to arrange a fork-lift to be hoisted up with a cage that could hold about four or five people at a time," he said.

"It is probably a good thing they didn't have to get everyone off in a hurry otherwise they would have had to use the emergency slides."

"Women with young children and anyone who felt unwell were asked to go to the head of the queue once ground staff had found a way to get us out."

While there was obvious frustration from some passengers, many praised the calm and professional nature of the staff who dealt with the unexpected situation.

A female passenger wishing to remain unnamed said she was travelling with her young daughter and it appeared the situation was under control from the moment the captain made the decision to reroute.

"I think everyone on board was calm and accepted that it was better to be safe," she said.

The stranded passengers faced a four hour wait at the Mount Isa Airport but eventually made it to their final destination after Qantas deployed a second aircraft from Brisbane.

The Boeing 767 remains grounded in Mount Isa this morning until engineers can assess the problem..

Qantas said the flight from Darwin to Brisbane was diverted to Mount Isa late yesterday as a safety precaution, after crew detected a smell in the cabin.

Today a Qantas spokesperson said: “Qantas flight QF825 Darwin to Brisbane diverted to Mt Isa as a safety precaution due to an odour being detected by cabin crew in the forward area of the cabin.

“The aircraft landed safely without incident.

“There was no emergency landing.

“At this stage nil defects have been found and the aircraft will be returning to Sydney this afternoon.”

Queensland Airports Limited, which owns the Mount Isa Airport, has so far declined to comment.