Williams International FJ44

Williams International FJ44-3ATW

The Williams FJ44 is a family of twin-shaft turbofan powered plants the US company Williams International , which for use in lightweight jet-propelled business aircraft have been developed. Until the mini-jet boom , the FJ44 was one of the smallest civilian turbofan engines available. Although it was originally designed by Williams, Rolls-Royce was involved in the design, development and production of the air-cooled high-pressure turbine from the very beginning.

The first flight of the FJ44 took place on July 12, 1988 as an engine for the Scaled Composites / Beechraft Triumph .

Models

Production began in 1992 with the 8.45 kN version FJ44-1A . This had a single-stage fan with a diameter of 531 mm with a single medium-pressure stage (booster), which is driven by a two-stage low - pressure turbine. It also contains a centrifugal high pressure compressor, which is driven by a single-stage high pressure turbine, and an annular combustion chamber . The specific fuel consumption at 8.45 kN thrust (SLS, ISA) should be 0.456 lb / hr / lbf. In the throttled version FJ44-1C with 6.67 kN this should be 0.460 lb / hr / lbf.

A more powerful version, the FJ44-2A with 10.23 kN thrust, was approved in 1997. It has a fan with a diameter of 551 mm and two additional booster levels to increase the core throughput. An exhaust mixer and an electronic fuel control system were also installed. The 10.67 kN FJ44-2C is similar to the -2A, but includes a hydromechanical fuel control system.

Further improvements were introduced with the FJ44-3A , which was approved in 2004 and delivers 12.54 kN of thrust . It was similar to the -2A, but had a larger fan and a two-channel FADEC . The 11.08 kN FJ44-3A-24 is a throttled version of the -3A.

In development (from the beginning of 2006) is the 16.01 kN thrust FJ44-4 , which has a highly developed fan with a larger diameter than the version -3.

In 2005, the FJ44-1AP, a new version with a lower output, was approved. The engine has a starting thrust of 8.74–9.34 kN, a 5% lower specific fuel consumption and manages with a lower core temperature (longer service life). It is similar to the -1A, but has a fan with a higher pressure ratio, a new combustion chamber and low pressure turbine, a new bypass mixer and a two-channel FADEC.

In addition to the FJ44 family, the Williams FJ33 (approved from 2004), a smaller engine family based on the basic design of the FJ44, was introduced.

Technical specifications

FJ44
model	FJ44-1A	FJ44-1C	FJ44-1AP	FJ44-2A	FJ44-2C	FJ44-3A	FJ44-3A-24	FJ44-4
Thrust (kN)	8,452	6.672	8.741-9.34	10.231	10.676	12,544	11.076	16.014
Specific fuel consumption (lb / hr / lbf)	0.456	0.460	?	?	?	?	?	?
Dry weight (kg)	209	209	208	231	236	238	243	295
Total length (m)	1.354	1.354	1.471	1.290	1.519	1.585	1.585	1,742
estimated fan diameter (mm)	531	531	526	551	551	582	582	640