CFM Leap Testing Now In Full Swing

Farnborough Air Show » 2014
The Leap-1B, set to power the Boeing 737 Max, ran for the first time in mid-June. Eleven miles of carbon fiber is needed to weave a single Leap fan blade.
The Leap-1B, set to power the Boeing 737 Max, ran for the first time in mid-June. Eleven miles of carbon fiber is needed to weave a single Leap fan blade.
July 11, 2014, 6:00 AM

By the end of the year, CFM (OE 22) plans to have put together and tested around 20 Leap-1A/B/C turbofans, in preparation for their first flights next year and in 2016 on their respective application airframes. The Franco-American engine manufacturer is also gearing up for a swift production ramp-up, planned to reach an annual 1,700 engines by the end of the decade. The Leap will power the Airbus A320neo (Leap-1A), the Boeing 737 Max (Leap-1B) and Comac C919 (Leap-1C) narrowbodies.

“We are in an acceleration phase,” executive v-p Cédric Goubet told AIN. On June 13 at Snecma’s Villaroche, France development and production facility, the Leap-1B ran for the first time and reached full takeoff thrust a few days later. On a neighboring test bench, a Leap-1A was approaching the “triple redline” test, where the fan’s and the high-pressure spool rotation speeds are taken to their maximum, simultaneously with the exhaust gas temperature. The triple redline test is itself a way to get ready for block test and endurance evaluations this fall. “Our tests are on schedule,” Goubet said.

Flying Testbeds

By the end of the summer, two Boeing 747 flying test beds will carry a Leap-1A and a Leap-1C, respectively. GE will operate them from Victorville, California. The two engines will first have been fired up on a GE ground test bench in Peebles, Ohio. A fifth engine, a Leap-1A, is due to start crosswind tests in Peebles in the coming weeks. “We are entering the most intense phase of the test plan,” Goubet stressed.

Both the -1A and the -1C are pegged for certification in 2015, immediately before their flights on the A320neo and the C919. For the -1B, CFM expects certification in 2016, just prior to the first flight of a 737 Max.

Meanwhile, the company has created a scale–ranging from 1 to 8–to measure the “manufacturing readiness level,” comparable to the well known “technology readiness level” in research and development. “MRL 6 is the minimum maturity to commit to production,” Goubet explained. MRL 8 corresponds to an entry into service.

In addition, stress tests are being organized to simulate a “run-at-rate” production. These tests take place at Snecma, GE and supplier factories. “We’ll be better prepared than ever,” claimed Goubet.

In final assembly, the so-called pulse line, already used for the CFM56, will also be used for the Leap. “The first Leaps will be assembled on fixed stations; transitioning to the pulse line will take 18 to 24 months,” Goubet said. On a pulse line, the engine moves at regular time intervals.

In April, Snecma signed a procurement contract with Mecachrome (Hall 4 Stand C17) for titanium-aluminide (TiAl) blades on the Leap’s low-pressure turbine. Located at Mecachrome’s plant in Sablé-sur-Sarthe, France, the new production line will require an investment of €60 million ($83 million). Volume production is to kick off in 2015, with a sharp ramp-up as soon as 2016, on the way to achieving the planned production rate of one blade every three minutes in 2019.

TiAl is a new-generation material that can withstand very high temperatures (up to 750 degrees Celsius). It will halve the weight of a blade, compared to the nickel-based alloys traditionally used in low-pressure turbines, according to Snecma.

In March, the new Safran Aerospace Composites plant in Rochester, New Hampshire, was inaugurated. Already ramping up production of composites fan blades, it is leading the way as a sister factory is being built in Commercy, France. Safran (Snecma’s parent company) has partnered with Albany Engineered Composites (Hall 4, Stand G14), a U.S. specialist in 3-D-woven composites based on carbon fibers. In each factory, Albany is in charge of the fiber weaving and resin injection, while Safran takes care of the remaining steps in the process–machining, bonding and inspections.

To fine-tune the production process, Safran and Albany manufactured more than 600 fan blades in 2013. About 30,000 are planned to be produced annually by 2019 for the 1,700 Leaps or so to be produced that year–11 miles of carbon fiber is needed to weave a Leap fan blade.

The CFM56 will be produced until 2019, at least­–the final year depending on customer demand, Goubet said.

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