Australian airline Qantas has been forced to deny allegations of systematic maintenance failure following the latest emergency landing.

A Qantas operated Boeing 747 was earlier forced to land in Bangkok while on route to Sydney after developing engine trouble.

Thai air traffic controller Somchai Thean-Anant confirmed the flight was forced to return shortly after takeoff with 352 passengers on board.

The incident is just the latest in a string at the airline, which had until recently prided itself as one of the safest in the world.

Just this week a Qantas Boeing 737, carrying 100 passengers six crew, fell 25,000ft in a rapid “but controlled” descent following a loss of cabin pressure.

Last week a flight bound for New York made an unscheduled stop in Fiji after another Boeing 747 developed a problem with a fuel valve supplying one of its engines.

Qantas Safety in 2010

In November last year a Qantas flight was struck by lightning while on route to Darwin, while a Boeing 747 carrying 171 passengers bound for Sydney turned back to Johannesburg in South Africa after a bird was sucked into an engine shortly after take-off.

Earlier in the month a flight from Sydney to Buenos Aires was forced to return to base mid-flight after the cockpit filled with smoke.

Qantas was also forced to temporarily ground its entire Airbus A380 fleet following an engine blow-out in Singapore.