A new WTO ruling is bad news for Boeing.

Singapore Airlines has grounded three of its Airbus A380 jumbo jets after carrying out an inspection on the planes' engines, according to media reports that have yet to be confirmed by the airline.

The airline says the three planes will be fitted with new engines as a precautionary measure.

Like Qantas, which has grounded its fleet of six A380s after a mid-air explosion in an engine of one of its planes forced emergency landing last week, Singapore uses Rolls Royce-manufactured engines.

 As Qantas prepares to celebrate its 90th anniversary, a second serious plane failure in as many days is taking the shine off celebrations and seriously denting market value of engine manufacturer Rolls Royce.

According to reports from Associated Press quoting a Qantas spokesman, a Sydney-bound Qantas Boeing 747-400 fitted with four Rolls-Royce RB211-524G-T engines landed safely in Singapore yesterday after an engine caught fire minutes after it took off.

An international safety warning was issued in August about the Rolls Royce engines used aboard the Qantas A380 super jumbo forced to make an emergency landing at Singapore yesterday after an engine exploded.

However, Emirates, which operates the only A380 service in and out of New Zealand, uses a different engine.

The engine used on the Emirates A380, which flies daily in and out of Auckland, is an Engine Alliance GP7200.

Investigators looking into the late November crash of an Air New Zealand Airbus A320 aircraft on a maintenance flight off the southwestern coast of France have been hindered by both a separate French criminal probe and failures to retrieve data from the plane's so-called black boxes, a report in the Wall Street Journal says.

Quoting sources that are “familiar with the details,” the paper’s reporter says “unusually few clues have emerged about possible causes.”

Air New Zealand has postponed an historic biofuel test flight, originally scheduled for this Wednesday, as the airline comes to terms with the tragic loss of four employees in an Airbus A320 crash off the coast of France.

The world-first biofuel flight will now take place in early January next year.

The two hour 747-400 flight from Auckland had planned to use a jatropha-based fuel, sourced from seeds grown on environmentally sustainable farms.