NBAA Convention News

Despite design milestones, Snecma still seeks Silvercrest launch platform

 - October 1, 2008, 8:08 AM

Snecma remains “very satisfied” with the performance of its Silvercrest core engine demonstration program despite its failure to secure a launch platform for the new-generation turbofan.

Silvercrest program general manager Laurence Finet told NBAA Convention News that “serious talks” are currently under way with airframers and risk-sharing partners in the $100 million design and development program for the 10,000-pound-thrust-range engine, with certification still expected in 2011 or 2012.

The Silvercrest engine was announced at the NBAA Convention in 2006, and on Nov. 30, 2007, the test campaign began on a dedicated rig to validate the design and overall integration at Snecma’s main design test facility in Villaroche, near Paris. The core engine has completed more than 80 hours of tests including more than 60 hours ignited, achieving its performance objectives. Tests have assessed the overall compressor performance, combustor performance and high-pressure turbine (HPT) efficiency, as well as evaluated the overall dynamic behavior characteristics. During its initial run, the engine reached its nominal takeoff speed of 20,300 rpm.

According to Finet, a mechanical engineer, the company has also tested rotor blade dynamic characteristics, high-pressure compressor (HPC) and HPT tip clearances and compressor pressure ratio and stall margins. A total of 660 real-time parameters were monitored during the test campaign. Snecma is now engaged in talks with at least two airframers, but Finet said he could not be more specific about those discussions.

The engine is being developed first for business jet applications, and later will be targeted to 40- to 60-seat next-generation regional jets. It will deliver 9,500 to 12,000 pounds of thrust, depending on airframers’ requirements. A typical application will be to power super-midsize and large wide-cabin long-range aircraft.

According to the company, Silvercrest will consume 10 to 15 percent less fuel than the current generation of engines, meeting Snecma’s objectives for the turbofan’s environmental characteristics and consistent with the noise and emissions margins that will be achieved by future larger narrowbody engines. It will feature at least 25 percent better climb and high-altitude cruise thrust than current engines. In addition, its simplified design reduces the parts count, significantly lowering the operator’s maintenance costs.

Building Business in the Regional Sector

The Silvercrest development is part of Snecma’s plan to lead the market for commercial engines for airplanes with fewer than 100 seats, and follows the recent launch of its SaM 146 engine for Sukhoi’s future Superjet 100 regional airliner. The turbofan is neither a scaled-down design nor a derivative of the CFM56 that Snecma produces under its 50-50 CFM International partnership with General Electric.
However, it does share with it some key technologies and development processes. Snecma said it has presented the engine design to all the aircraft makers currently involved in the regional transport and business aircraft markets. According to Finet, initial feedback to the intended launch of a 9,500- to 12,000-pound-thrust engines has been “very positive.”

Silvercrest will benefit from Snecma’s experience with the low-pressure CFM56 civil turbofan. CFM International powers the Boeing 737-300 to -900 family of aircraft, the Airbus A320 family, the Airbus A340-200 and -300 and the Airbus A340. With close to 500 operators and clients, 18,000 CFM56 engines are currently in service on almost 7,200 airplanes, including more than 6,500 Boeing and Airbus jetliners. CFM last year produced a record 1,264 engines and booked orders for 2,704 more–also a record. The joint venture expects to produce 1,350 to 1,380 engines this year.

Snecma initially was “disappointed but not devastated” after Rolls-Royce won the contract to supply the 10,000-pound-thrust engine for Dassault Aviation’s developmental super-midsize business jet. Snecma’s Silvercrest was among five possible candidates to supply the engine for the airplane. Finet emphasized that the competition was the company’s first in that sector, and that it competed with more established manufacturers of business jet engines.

While hopeful, Snecma never expected to win its first Silvercrest competition, Finet said, “especially as we had not yet run our demonstrator. Perhaps we started a bit late. But we did well in the final stages and learned a lot. We are encouraged as we understand that our engine received a high rating. Snecma has produced engines for 50 years and we are learning what airframers want from our big powerplant technology applied to a small engine. The market potential is strong enough to support several new airframe projects requiring Silvercrest power, and we are in active contact with other potential customers.”

Snecma is now evolving Silvercrest’s pre-design, refining airframers’ requirements and needs and reviewing the architecture. According to Finet, so far, “Everything is in line with our forecasts. We are very happy with the core’s performance which, for a first run, has gone beyond our expectations.”