China’s aerospace industry lacks experience and the C919 is demonstrably late – 5 years late so far.
Hit by repeated technical issues the latest is said to be a mathematical issue, basic miscalculation of the load in the engines from air pressure in flight. The wrong information was provided to engine supplier CFM.
As a result the wing, engine pylon and nacelle connecting points have all had to be redesigned and strengthened.
So far cracks in the horizontal stabilisers resulted in a redesign, cracking on the engine gearbox resulted in a test flight shut down.
Of the six aircraft so far built the gearbox oil leaks have been so severe that it’s curtailed flight testing. None of the aircraft are considered reliable.
Severe vibration in the engines has also lead to a software redesign to alleviate the problem, a Pratt&Witney issue.
The Chinese have been so desperate to get technology that a wide ranging group of Chinese spies were caught, and are being prosecuted in the US for IP theft of technology from 13 different companies including CFM.
China has made some 830 orders for the aircraft, all bar one small one for domestic operators, none of those orders are more than provisional.
Fears rise daily that the project has missed its time slot in the global ordering cycle and it will never be a success, that cycle is likely to enter its low point in 2020-22.
However when it gets finished China will have learned a great deal, using stolen technologies and incorporating them into a new aircraft type with help from many of the companies it stole from, its next project might have more success. The long haul jet in development with Russia may be a different story. Then again civil airliners have never been a Russian strong point either.