Melbourne-based carrier Skytraders is investigating an incident last week involving its Airbus A319 aircraft, which taxied at Cocos Islands airport while its built-in stairs were deployed.
The airline's chief pilot and director of operators Terry Vickers says the 9 May incident was a result of human error and an erroneous cockpit indicator.
During the cabin door closing procedure, the stairs at the front left-hand side of the aircraft were left deployed and a cockpit warning indicator failed to alert the crew to the problem, he adds.
"The indicator in the cockpit said the stairs were retracted and the doors were closed," says Vickers.
The aircraft taxied at the airport for 50m to 100m before a flight attendant, "who could hear the noise of the stairs scraping along", alerted the pilots to the problem, says Vickers.
Refuting earlier reports, Vickers says the aircraft did not attempt or start to take off with the stairs deployed.
Skytraders, which operates flights to Antarctica for the Australian government, is investigating the incident and awaiting the jet's return to its Melbourne base, says Vickers.
There was no damage to the aircraft and it "is flying as we speak", he adds.