Bolstered by the selection of its Silvercrest mid-thrust turbofan for Cessna’s newly launched Hemisphere business jet, Safran Aircraft Engines has detailed a revised development schedule incorporating improvements made to counter problems uncovered in early tests.

First announced at the 2006 NBAA convention, the Silvercrest was launched by Dassault to power the Falcon 5X, which was originally targeted at entry into service in 2017. However, development issues with the oil-fuel heat exchanger and later performance retention have delayed the debut of the French business jet until 2020.

Designated the Silvercrest 2C for the Hemisphere, the new variant will be modified with external accessories for the Cessna jet but will otherwise be architecturally identical to the -2D for the Falcon 5X. Describing the Cessna decision as a “vote of confidence” in the engine, Olivier Andriès, CEO of Safran Aircraft Engines, says, “We had issues with the development of the Silvercrest that became apparent over the course of last year. We have worked very quietly and hard with Dassault to solve the issues, and I can say today that the issues are behind us.”

The modifications are targeted mainly at performance retention, says Silvercrest program general manager Michel Brioude. “What we looked at was carcass distortion and clearance control as well as software. But the hardware modifications were mainly driven by vibration, distortion and performance and secondary airflow optimization for clearance control.” The design, which unusually for an engine in the Silvercrest’s 10,000-to-12,000-pounds-thrust range incorporates an axi-centrifugal compressor, is also being revised to include active clearance control in both the high- and low-pressure turbines.

An engine in the Dassault configuration combining all the modified features is under assembly and will enter tests in December. “Then next year we will conduct different tests for certification like vibration, cyclic and high-temperature endurance, and later next year we will have an engine going to Russia for extreme and cold weather conditions,” Brioude says. “At the same time, we will develop software and power management and have two engines ready for evaluation at altitude test facilities in Saclay, France, and in Russia. Plus we have another on the Gulfstream 2 flying testbed in San Antonio,” he adds.