Sub-assemblies of the first CFM Leap-1B for Boeing’s 737 MAX test program are nearing completion on both sides of the Atlantic in readiness for the mating of components at Snecma’s Villaroche site in France starting in March.

The transfer of the initial -1B high pressure core from General Electric to its CFM joint venture partner represents a key milestone in the fast-paced development effort which includes the new -1A engine for the Airbus A320neo and the -1C for the Comac C919. “For 2014 as a whole we will have 20 different engine builds on test,” says CFM executive vice president Chaker Chahrour.

To date, the Leap test program has produced no noteworthy surprises or issues, says Chahrour who adds the key concern is “really the volume of test engines we need to build and bring to test, making sure all the tests stay in sequence and that we don’t have any hiccups with the test sites. The biggest challenge is staying on schedule and making sure we go up on test on time and finish on time. We cannot afford a major hiccup on any of the engines. It’s all about execution this year.”

“We’re in the process of building the first -1B core and are within a couple of weeks of shipping it to Snecma. They are building the fan module, low pressure turbine and gearbox as we speak and assembly will start in March,” says Chahrour. Ground tests of the Leap-1B are scheduled to get underway in mid-June, with airborne evaluation beginning in early 2015 on one of GE’s two 747 flying testbed aircraft. The first -1B powered 737 MAX is due to make its maiden flight in 2016 and set to enter service in 2017.

“So we have got lots of engines coming to test in the next three months and, overall, will have seven added to the program between now and the end of April,” he says. “In May we do the first flying testbed campaign for the Leap in the -1C configuration,” he adds. The initial -1C is in build and will be finished this quarter. “It will go to Victorville, Calif, for installation and we’re getting the pylon ready to mate to the engine to the wing of the 747.”

For the first time in any CFM program, the engine maker is also providing the Leap-1C with a fully Integrated Propulsion System (IPS) in conjunction with Nexcelle, a 50/50 joint company between GE’s Middle River Aircraft Systems and the Safran group’s Aircelle. The IPS includes the nacelle, thrust reverser, and exhaust system delivered as a complete package. Comac meanwhile delivered the engine pylon for the flight test aircraft to CFM late last year even though the Chinese aircraft program is running later than planned.

Initial performance of the first Leap-1A engine has produced “thrilling” results, he adds. The engine, which began ground tests at Peebles, Ohio, in September, was later sent to Winnipeg, Canada, where it completed more than 20 hours of risk-reduction icing tests before returning to GE in early February. The work prepares the ground for a second set of icing tests in advance of certification which is targeted for mid-2015. The -1A is due to become airborne for the first time on the 747 flying testbed in September, around a year before it powers the first CFM-equipped A320neo.