Russian airframer Sukhoi is investigating the use of advanced composite materials on a future stretch variant of the Sukhoi Superjet 100 (SSJ) regional jet together with Finmeccanica unit Alenia.
Under a late 2006 deal through which Alenia took a 25% stake in Sukhoi and a corresponding financial stake in the development of the Superjet programme, the Italian aerostructures specialist agreed to support the future use of advanced composite materials on the jet.
Speaking at Sukhoi's Moscow design centre Igor Vinogradov, Sukhoi Civil Aircraft first vice-president and SSJ programme director, added that the 95% commonality between 75- and 95-seat variant could additionally allow an analogous 15% composite use on the wing, achieving a 300kg (660lb) weight saving.
"If we find an effective solution we could use composites on both," he said.
Ground trials of the Sukhoi Superjet 100's PowerJet SaM146 have also confirmed that the engine could power a 120-seat stretched version of the baseline 95-seat regional jet.
The move would allow Sukhoi - known to be studying a larger, 110-seat version of the regional jet - to respond to pressure from launch and potential customers including Aeroflot to increase capacity without having to develop a new variant of the engine.
The SaM146, developed by Russia's NPO Saturn and France's Snecma through the PowerJet joint venture, has achieved a thrust of 18,600lb (82.7kN), exceeding the design rating of 17,400lb.
This could be further increased because of a 900lb thrust reserve at the entry to the high-pressure section, according to Igor Yudin, executive director of NPO Saturn.
"Essentially, it's the airframer's decision. We have conducted studies and the results of that investigation have shown that a version for 110-120 passengers would be possible without any redevelopment of the engine required," he says.
Jean-Pierre Anger, deputy SaM146 programme director, says: "Sukhoi will not talk about exact capacity desired although if they wanted to go for a 140-passenger aircraft, I am not sure we can deliver an engine for that. What is for sure is that we have an engine that could carry 110 passengers."
Sukhoi's Vinogradov said a stretched version would not be feasible before 2011 if Sukhoi went ahead with the development of a 75-seat variant. "A 95-seater could still carry 108 passengers. Less comfortable, admittedly, but more effective than a stretched version."
Ground testing of the third of eight SaM146 development engines has been under way since May 2007 and will progress to a flying test bed in September where performance calibration, fan stress and ground instrumentation verification will be carried out using an adapted Ilyushin Il-76 at the Gromov Flight Research Institute before transferring to France in November for four months of further testing at Istres.
Engine certification is scheduled for March 2008 with aircraft certification due in October 2008.
Source: Flight International
