Program officials from China’s Comac say the orderbook for the C919 airliner could double by year end, pending the outcome of campaigns underway in Asia and Europe.

Updating progress on the 150-seater, Comac says the preliminary design review has been completed and “we are preparing to exit the joint development phase in the near future,” says chief designer, Wu Guang Hui.

Wu was commenting at a signing ceremony for the master contract with CFM International for the C919 integrated propulsion system. The signing is the first official contract with a major supplier to be completed on the aircraft which to date has attracted around 100 orders and options.

“My personal hope is that we will get between 50 and 100 more by the end of the year,” Wu says. Although initial sales efforts have been focused on Chinese domestic carriers, Wu adds “we are now exploring overseas markets including south east Asia and Europe.”

The program “is on schedule, but we have challenges,” he adds. Although no specific issues have been disclosed, program officials say the main watch items are concerned with integration between the systems and struvtures under development by Chinese and international parners.

The contract at Paris was signed between Comac subsidiary Shanghai Aircraft and CFM and stipulates CFM will be the sole overseas supplier of the Leap-X1C engime, nacelle and thrust reverser. It also stresses that Leap will be the exclusive western engine on the C919, effectively cutting out the competing Pratt & Whitney geared turbofan. The nacelle will be developed by Nexcelle, a joint venture between GE’s Middle River Aircraft Systems and Safran’s Aircelle.

Comac expects to offer a Chinese engine option on the C919 from 2020.