CFM International is still in talks with the Chinese about establishing a local assembly for the Leap-1C engine in China and does not foresee making a decision until 2014.
The engine maker is in discussions with AVIC Commercial Aircraft Engines (ACAE), the European Aviation Safety Agency and the Civil Aviation Administration of China to work out the best approach for the joint venture, CFM's executive vice-president Chaker Chahrour tells Flightglobal.
CFM and ACAE signed a memorandum of understanding last June to study the Leap-1C's local assembly in China.
"We're still trying to work out where to build the facility and how do we define that in terms of the production certificate," he says. "There are many options. We are trying to decide which is the best and easiest approach for all parties. It's going to happen, it's a matter of when we start. We have to make sure everything is in place."
The decision centres on whether there is a business case to assemble the Leap-1C in China.
"It doesn't really make sense to have a manufacturing facility in China when we have one for the same engine in the USA and France," says Chahrour.
"Six hundred engines don't make a solid business case. But we know there will be more orders and it's not just about the number of engines, but also how the joint venture is formed."
In July, Flightglobal reported that the negotiations have dragged on because of uncertainty over the origin of the production certificate for a Chinese-built Leap-1C.
Having a local factory would require CFM to receive local certification from the Chinese authorities.
CFM could also assemble the engines in China under production processes certified by Snecma in France or by GE in the USA. However, this comes with the risk that any quality or safety issues with China-built engines could affect all those built using the same certificate in either France or the USA.
Building the engines under a Chinese production certificate, meanwhile, risks sharing the joint venture's intellectual property (IP) with the Chinese government.
"There really are many options, so we need to decide which is the best way forward. The basic premise is that it's done with the least amount of hardship and exposure to our IP protection," says Chahrour, adding that the issue is not "a show stopper".
A decision is likely to be made only in 2014 because CFM has no intention of manufacturing the first compliance engine in China and the C919's entry into service is scheduled for 2016.
Development of the Leap-1C, meanwhile, is progressing well and on track for the first engine test in 2013 and for the C919's first flight in 2014.
Comac has received 330 orders for the C919 so far.