Snecma started powering up for its first foray into business aviation just as the sector itself was about to power down. Seven years on from the beginning of the test campaign on the Silvercrest core engine demonstrator in December 2007, the French propulsion specialist is convinced it made the right strategic move in launching full development of the 9,500-1,200lb-thrust (42.3-5.33kN) programme three years later without a confirmed customer.
Since then, two airframers have chosen the high-bypass turbofan for new twinjets: Dassault for its wide-cabin Falcon 5X business jet, unveiled at the NBAA show last year after a long, undercover development as the SMS project; and Cessna for its super-midsize, top-of-the-range Citation Longitude, one of a pair of related, all-new models the Wichita manufacturer is readying for certification. Both the 5X and the Longitude are due to enter service in 2017.
Although the period since the birth of the Silvercrest has been tough for business aviation – with orders and deliveries still way below 2007-2008 peaks – the larger-cabin, longer-range segment which Snecma chose to play in has suffered less, with the emerging-billionaire markets of Asia and the former Soviet Union helping sustain demand. In fact, François Planaud, director general of Snecma’s commercial engines division, believes there is potential for further applications for Silvercrest. “We are in the right part of the market,” he said. “And we are reasonably confident there are other opportunities for this engine in the years to come. Silvercrest is the only modern engine in this thrust class for some years.”
Seven test engines have run moe than 1,200h on Snecma's outdoor test stands at its main facility in Villaroche near Paris
Snecma
A more powerful variant – for new longer-range types coming on the market – is an option. “It is possible to do a family around it, and one of the things we want to find out from testing is how far we can go, whether we can provide additional thrust,” says Planaud.
Snecma says its market research points to “dynamic growth” in the “high-end” business jet segment, with demand for 8,000 new aircraft over 20 years. While not immune to the downturn, brands such as Bombardier’s Global range, Dassault’s Falcons and Gulfstream have continued to sell strongly. And although a cash crisis forced Cessna to cancel its large-cabin Citation Columbus 18 months after launch in 2008, the US manufacturer has expanded its top-end offering with the Longitude and Latitude.
The Safran subsidiary is now entering the final phases of validation on the Silvercrest 1D before engine certification and handing over the first 11,450lb-thrust examples to Dassault in time for the French airframer to begin its flight test campaign with three 5Xs in mid-2015. The Longitude – which will use the 11,000lb-thrust 1C version of the Silvercrest – is due to fly in mid-2016, with entry into service in the latter part of the following year.
The first Silvercrest began ground testing in October 2012 and flew for the first time on a modified Gulfstream GII flying testbed in April this year. It swill be replaced on the GII by a second Silvercrest later this year. Seven test engines have run for more than 1,200h on Snecma’s outdoor test stands at its main facility in Villaroche, near Paris, and on the open-air test cell in Istres, southern France. Endurance tests have been carried out at Safran unit Techspace Aero in Belgium.
For Dassault, it will be the first time a Falcon has flown with an all-new engine, and it is perhaps fitting for Snecma that a fellow French aerospace champion is the Silvercrest’s launch customer. Variants of the Pratt & Whitney Canada PW307 power most Dassault business jets, with the Falcon 900LX using three Honeywell TFE731s. Cessna too has been a P&WC stalwart, with the PW306 powering its Citation Sovereign. Its other top-of-the-range model, the Citation X+ has the Rolls-Royce AE3007.
Production of the test examples of the Silvercrest has begun in a corner of Snecma’s vast Villaroche final assembly hall, a facility dominated by CFM56s in various stages of completeness. As part of its role in the CFM International joint venture, Snecma builds the fan and low-pressure sections and assembles half of all CFM56s – which power current-generation Boeing 737s and around half of Airbus A320 family aircraft. Some 750 complete engines will roll out of Villaroche this year.
Snecma says the Silvercrest benefits from the manufacturer’s “four decades of experience in the design and production” of the best-selling commercial engine ever, with more than 25,000 CFM56s delivered. Output of the Silvercrest will be on a somewhat different scale, with an initial rate of two engines a month. How production ramps up depends on Dassault’s and Cessna’s success with their programmes, but overall production will be in the tens rather than hundreds a year.
Interestingly, Snecma’s 50% partner in CFM, General Electric, is making its own journey into the business aviation market with the Passport engine, which will power the Bombardier Global 7000 and 8000 jets under development. However, because that engine is in the much bigger 18,000-20,000lb-thrust category, Planaud says there is no likelihood of conflict with its transatlantic counterpart even if Snecma decides to pursue a higher-powered iteration of the Silvercrest.
Cessna's Citation Longitude will use the 11,000lb-thrust 1C version of the engine
Cessna
Further competion for both Snecma and GE could come from Pratt & Whitney, which is continuing a test programme for its PW800, despite the lack of an announced customer. Although the United Technologies subsidiary will not comment on the programme - which was originally earmarked for the cancelled large cabin Cessna Citation Columbus - production work is underway in the supply chain and the engine is strongly rumoured to be the choice for the new jet Gulfstream is likely to launch at NBAA.
The 10-20,000lb-thrust PW800 is derived from the core of the PurePower geared turbofan engine developed for narrowbody airliners including the Airbus A320neo family, Bombardier CSeries, Embraer E-Jet E2, Irkut C919 and Mitsubishi Regional Jet. However, it does not include a fan drive gear system and will be assembled, along with the manufacturer's other business aviation and general aviation engines, by Pratt & Whitney Canada in Montreal.
Service is another area where the business aviation market will prove very different to Snecma's experience with the CFM56, which tends to be operated in large volumes and high cycles. Business jet owners, by contrast, generally operate single aircraft or small fleets and tend to deal in the first instance with the airframer rather than engine manufacturer. “We have had to take a very different approach to customer support,” admits Planaud. “It is very different to the airline world”.
To this end, Snecma is setting up a dedicated network of spare part centres, each with a customer response team. The first has been established in Dallas, a second will be opened in Europe – most likely Paris, while an Asian location will selected by the end of the year. “We have done a lot of work with people who have experience in business aviation,” says Planaud. “It’s an exciting challenge and a journey that is very important for us to get right”.
Source: Flight International
