SYDNEY - An electrical fault sent smoke into the cockpit of a Qantas Boeing 747 and forced pilots to turn back Monday in the latest in a string of problems for the airline since an engine explosion on a superjumbo prompted a global safety scare.

The latest incident was unrelated to the superjumbo drama, but it was the third time Qantas jetliners have aborted flights because of faults since the Nov 4 explosion on the Airbus A380, which raised concerns about the world's largest passenger plane.

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The Airbus incident has prompted extra attention on Qantas, which prides itself on its safety record. Qantas says the three faults since Nov 4 were far less serious than problems with the A380 and that the turnarounds were precautionary.

The airline said a Boeing 747 carrying 221 passengers and crew was an hour into a flight from Sydney for Buenos Aires, Argentina, when smoke started coming from an instrument panel in the cockpit. Pilots donned oxygen masks and turned the plane around, dumping fuel over the Pacific Ocean before making a "priority landing" in Sydney.

"This is absolutely in line with procedure to ensure that they can safely arrive, which they did," Qantas spokeswoman Olivia Wirth told reporters.

Passengers said the pilot informed them that there had been a problem with an instrument panel in the cockpit and the plane would return to Sydney.

"We couldn't smell or hear anything," passenger Samantha Gash told Nine Network television. "All we noticed, because we were next to the wing, is when the fuel was let out. Everyone was very quiet and calm. It was probably when we landed back in Sydney and there were four or five fire engine trucks behind us that people began to start to feel a bit uneasy."

Television footage showed fire trucks tailing the plane as it taxied to the terminal, though they were not put to use. Qantas said the passengers would be put on other flights, and repairing the plane was not expected to take long.

Wirth said the problem was a "minor electrical fault" that caused a "minimal" amount of smoke in the cockpit. No smoke entered the passenger cabin.

On Friday, a Qantas Boeing 767 turned back on a domestic flight in Australia after pilots detected abnormal vibrations in one of its two General Electric engines. A week earlier, a Sydney-bound Qantas Boeing 747 landed safely in Singapore after an engine caught fire minutes after takeoff.