Another Qantas plane has been grounded after a loud engine noise was heard just before takeoff.
Media reports say the flight was due to leave Sydney for London on Saturday night but passengers were pulled off the plane after a loud noise was heard from the engine.
The plane had been taxiing towards the runway.
Earlier on Saturday, Qantas chief executive Alan Joyce had held a media conference to assure the public the company is now "100% confident" its A380 planes are safe.
Mr Joyce flew the Singapore leg on the first A380 plane to return to service since the fleet was grounded three weeks ago when an engine exploded on a flight from Singapore.
Qantas said its aircraft had undergone extensive work and are safe to fly.
Modifications have been made to the Rolls-Royce engine used on 20 A380s by three airlines - Qantas, Lufthansa and Singapore Airlines.
The Airbus is the world's largest passenger airliner, a double-decker that can carry up to 800 people.