Ten years after abandoning development of its then-largest business jet, Textron is suspending its latest flagship Cessna Citation programme, the Hemisphere.
In 2009, the collapse of the business jet market as the global recession took hold was behind the decision to axe the super-midsize Columbus. This time, a failure by Safran Aircraft Engines to fix problems with the Silvercrest turbofan is to blame for the termination of the 4,500nm (8,330km)-range large-cabin jet.
It comes less than a year after US fractional ownership operator and Citation loyalist NetJets put its faith in the Hemisphere with an order for up to 150 examples of the 19-seat type at the National Business Aviation Association convention in Orlando in October 2018, becoming the launch customer.
NetJets, which said at the time that the Hemisphere delivered “long overdue innovation to the $30-40 million large-cabin aircraft category”, says its agreement with Textron had always been conditional on the engine’s approval, adding: “[The Silvercrest] did not meet the requisite performance specifications, and thus at this time NetJets and Textron Aviation are exploring other potential options for the future.”
Safran said on 17 July that the contract with Textron had been “terminated with no financial impact for either partner”, acknowledging that the “aircraft/engine combination does not currently meet all the objectives”.
Textron had been awaiting the outcome of engine ground tests after Safran redesigned the Silvercrest’s high-pressure compressor (HPC). Although the performance of the new HPC had “exceeded expectations”, the French company says further trials are necessary to “confirm engine improvements and complete overall engine performance and durability validation”.
Speaking at an analysts’ briefing on 18 July, Textron chief executive Scott Donnelly said the US company had put the programme on hold because “we determine that the engine has not yet demonstrated the performance required for the aircraft design”.
The Textron decision means the 9,000-12,000lb (40-53kN)-thrust Silvercrest, which has been plagued by delays, has now lost both its platforms. In 2017, Dassault Aviation cancelled its 5X programme, opting to launch the Pratt & Whitney Canada PW800-powered 6X in its place. Safran says it will continue the Silvercrest effort as an “R&T platform”.
Donnelly insists that the decision to suspend the Hemisphere was solely down to the Silvercrest, and the fact that it was the only powerplant capable of matching its performance requirements. “It was purely the engine,” he says.
“We think that the niche…was an area that would be a great product and a great price point, performance point to go into the marketplace. But the challenge was there was really only one engine in development suitable to meet that performance point.”
Donnelly leaves the door open for a future reboot of the programme. “Any decision…in the future would depend on the state of the market, proven engine performance and a competitive landscape at the time,” he says, noting that Textron’s engineering focus is now on the delayed super-midsize Longitude, as well as its smaller SkyCourier and Denali programmes, both due to make first flights this year.
However, he adds: “I think just too much time has gone by here and…we can’t expect our customers to wait any longer.”
Safran has spent much of the past two years on the HPC redesign after performance issues were uncovered during early flight trials in the second half of 2017.
In January 2018, Donnelly admitted that the future of the Hemisphere programme hinged on Safran coming up with a remedy for the Silvercrest’s problems, and that using a larger engine – such as the PW800 – was not an option.
Safran had pushed the Silvercrest as the most fuel-efficient engine in its class, thanks to the axial-centrifugal architecture of the HPC, a feature usually only seen in engines below 7,000lb thrust. However, tests at high altitude on the flying testbed had found that the engine was slow to accelerate or decelerate on command.
Source: Flight International