Snecma Silvercrest

Design and development

Announced at the 2006 NBAA convention, the engine was originally designed as an 8,500- to 10,500-pound thrust turbofan to power super mid-size to large cabin business jets or 40 to 60-seat regional jets with a MTOW between 45,000 and 60,000 lb. Lately, thrust range has been quoted to 10,000 to 12,000 pounds.

The two-shaft engine architecture includes a 42.5-inch (1.08 m) fan with solid wide-chord swept blades, followed by 4 boost stages, all driven by a 4-stage low pressure turbine. The HP spool has 4 axial compressor stages and 1 centrifugal stage, driven by a single-stage turbine. An axi-centrifugal compressor is unusual for an engine in this 10,000-to-12,000-pounds-thrust range.

Turbomeca, which like Snecma is a part of the SAFRAN Group, participates in the design of the centrifugal compressor stage.

Early design featured a smaller 40-inch fan, no booster, one more high-pressure compressor stage, one low-pressure turbine stage less and a lower 4.5 bypass ratio. At an early stage of the project, the overall pressure ratio was 27:1 with a core pressure ratio of "over 17".

The high pressure spool and combustor have been run in a US$120 million core-demonstrator called SM-X, reaching the take-off speed of 20,300rpm. While a full engine demonstrator was due to run towards the end of 2008, the FETT (First Engine To Test) started ground-based testing in September 2012. After a 6+ month delay, the in-flight tests started mid-2014 on a Grumman Gulfstream II and should take place in Istres.

Engine certification, originally pencilled in for the end of 2010 or early 2011, has been re-scheduled for late in 2016. Availability was planned towards 2012.

Applications

Silvercrest

Cessna Citation Hemisphere, first flight 2019, with over 12,000 lbf (53 kN) of thrust.

Silvercrest SC-2D

Dassault Falcon 5X ; 11,450 lbf (50.9 kN), both aircraft and official engine selection were simultaneously unveiled at the National Business Aviation Association annual convention in October 21, 2013. Entry into service: 2020

Specifications (2D)

Data from Snecma.

General characteristics

Type: axial and centrifugal flow, twin-shaft, bypass turbofan engine

Length: approx. 74 inches (1,900 mm)

Diameter: 42.5 inches (1,080 mm) Fan

Dry weight: 2,290 lb (1,040 kg)

Components

Compressor: 4 low-pressure stages, 4 high-pressure blisks + 1 centrifugal stage

Turbine: 1 high-pressure, 4 low-pressure stages

Performance

Maximum thrust: 11,450 lbf (50.9 kN)

Overall pressure ratio: 38.5

Bypass ratio: 5.9:1

Thrust-to-weight ratio: 5:1