PARIS (Reuters) - French investigators are preparing for an intricate operation to repatriate an Air France Airbus A380 passenger jet that was forced to make an emergency landing in Canada after one of its engines came apart in mid-flight, people familiar with the manoeuvre said.

FILE PHOTO: An Air France Airbus A380 is seen during an emergency landing in Happy Valley-Goose Bay, Canada, September 30, 2017, in this still image taken from a video obtained from social media. Daniel Mcneely/via REUTERS

The Airbus superjumbo diverted to Goose Bay in Labrador on Sept. 30 after one of its four engines exploded over Greenland, sending the front part of the engine including its 3-metre-wide fan into the ice sheet 37,000 feet below.

More than 500 passengers and crew, some of whom had reported a bang and vibration, were picked up on two replacement jets after waiting for hours onboard due to problems in accommodating the world’s largest airliner at the remote military airport.

But the aircraft itself remained stranded while French-led investigators collected evidence and developed a plan for returning it to France.

Making the roughly 2,300 nautical mile (4,260 km) trip will need a switch in engines to help the mammoth jet fly smoothly.

First, the rump of the broken engine will be taken off the wing and flown to Wales, where manufacturer General Electric can examine it at its Cardiff repair workshop, the people said.

Then a spare engine will be mounted on the right wing in the same outer position as the damaged one. But this will only be used to balance the weight during flight and that engine will not be operable.

The people declined to be quoted as the plans have not yet been announced. France’s BEA accident agency declined comment.

The operation to fetch the double-decker jet is not the only challenging errand triggered by the mid-air explosion.

Some parts of the engine were retrieved by helicopter in Greenland on Oct. 6 and dispatched to BEA headquarters in Paris. But investigators still face a tricky search in uncertain weather conditions to try to find other missing elements before they are buried by snow.

Although nobody was injured, the engine break-up has led to what could be a lengthy investigation to ensure other aircraft are not exposed to the risk of damage from high-speed engine debris. Experts say such incidents are very rare, however.

GP7200 engines used on Air France A380s are made by Engine Alliance, co-owned by GE and Pratt & Whitney.

In 2010 a Qantas A380 engine built by UK rival Rolls-Royce blew up shortly after take-off. Investigators cited a poorly manufactured part.