Qantas not concerned about 747s

Qantas chief executive Alan Joyce says the airline is not concerned about the safety of its fleet of Boeing 747-400 jumbo jets, after one of the aircraft suffered a mid-air engine failure.

The incident in Singapore on Friday was the second engine issue in two days involving a Qantas plane.

Mr Joyce described the incident involving QF6, which was on its way to Sydney carrying about 400 passengers, as a "contained engine failure".

"Six minutes into the flight, the pilot experienced a problem with the number one engine," he told journalists at the Qantas Jet Base in Mascot, near Sydney airport, on Saturday.

"There were smoke and sparks coming from the engine.

"So, the pilot followed procedure and landed safely in Singapore."

Mr Joyce said there were different issues with the 747 engine, compared to the engine failure involving one of its A380 superjumbo jets on Thursday.

"This is a contained engine failure," he said of the later incident, adding that no debris left the engine as had occurred in the A380 incident.

The A380, also on its way to Sydney, was forced to turn back to Singapore after a mid-air explosion in one of its four engines over the Indonesian island of Batam.

Mr Joyce said Qantas was still carrying out engine checks on all of its six A380s, which were grounded after the incident.

"We are hopeful that within days we will have our A380 fleet flying again," he said.

"We are not concerned about our 747 fleet.

"Those engines have a long life ... We've seen infight shutdowns take place before ... It's a liability not a safety issue."

Asked if he thought the 747 had been sabotaged, he said: "We do not believe this is sabotage. It looks like a mechanical failure of the engine".

Mr Joyce said the 747 passengers were put up in hotels overnight and would be picked up soon.

"We are flying an aircraft to Singapore today to fly the passengers back," he said.

Asked if Qantas, which on Saturday is celebrating its 90th anniversary, had suffered brand damage because of the incidents, Mr Joyce said safety was the carrier's first priority.

He also repeated that Qantas carried out 92 per cent of its aircraft maintenance in Australia, with the remainder outsourced overseas to "the best" in the world.

- AAP