The design of the CFM International's Leap-X1C engine, which will power the Chinese Comac C919 narrowbody, is expected to be frozen "within several weeks".
The development will next enter the detailed design phase and the manufacturer will also start fabricating components to start building the first full engine for tests, a CFM spokeswoman tells Flightglobal.
The powerplant manufacturer is also building its third eCore demonstrator, with tweaks incorporated from previous core tests findings, and is scheduled to undergo testing in early 2013.
"In the next 18 months or so, we will complete another core test, the first full engine test and continue to conduct component and rig tests to further refine the design," adds the spokeswoman.
The first full engine is scheduled to go on test in the third quarter of 2013. The engine will then be tested on CFM's flying test bed in 2014, followed by the first flight on the C919 that same year.
"The programme is on schedule to enter service in 2016," adds CFM.
The manufacturer also claims that two earlier core tests, the latest of which featured a 10-stage compressor and two-stage high-pressure turbine, produced "outstanding" results.
"These tests validated the performance and operability characteristics of the cores, which ran smoothly and met all pre-test predictions," says the spokeswoman.
CFM has also successfully completed rig tests on an ultra-high efficiency low-pressure turbine. Next year, it will mate the turbine with a high-pressure turbine in a dual-spool rig test.
Meanwhile, its demonstrator engine has gone through a 5,000 cycle endurance test where the blades came out with "none of the damage propagated".
CFM has 470 Leap-X1C orders for the C919. The Chinese commercial aircraft, though initially powered by CFM's engines, will switch to home-grown engines when it is fully developed.