Will we ever be able to use a cruise missile to fly from point A to point B for our next business flight, charter trip, or family vacation? Trick question… We already can! You may be familiar with the Williams International FJ44 family of turbofan engines, widely used across the business aviation industry in popular aircraft like the Citation CJ series, the Pilatus PC-24, the Premier I/IA, and various other retrofit and re-engine applications. What many people don’t know is that the FJ44 actually began its journey far from the world of business aviation—as the turbofan used to power American cruise missiles like the ALCM and the Tomahawk.

In the 1950s, a young mechanical engineer named Sam Williams left Chrysler to start his own company. Williams excelled at creating small turbofan engines that were lightweight and simple in design, finding early success by powering short-range reconnaissance drones for the military. He continued to focus on minimizing size and weight while increasing fuel efficiency, eventually developing the 600-pound-thrust F107 engine. The F107 became the primary propulsion system for long-range cruise missiles like the Navy’s Tomahawk and the Air Force’s Air-Launched Cruise Missiles (ALCM). The F107 was a huge success, with Williams producing more than 6,500 F107 engines over the next 30 years. For his achievements with the F107 engine, Williams was awarded aviation’s highest honor, the Collier Trophy.

Williams had long dreamed of creating a small civil turbofan engine that could power a new segment of light business jet aircraft. As early as the 1970s, he began adapting his cruise missile technology to pursue this goal. The challenge was to take a specialized cruise missile power plant, designed to start once and run for three or four hours, and adapt it into a commercially viable engine. Simplicity and reliability were key to this new class of aircraft, and so the development of the FJ44 commenced. When completed, the FJ44 had just 700 total parts—one-quarter the amount found in most business jet engines. Additionally, the FJ44 weighed one-tenth the weight of the Pratt & Whitney JT8D engine but had the same specific fuel consumption and thrust-to-weight ratio.

Williams believed so strongly in his FJ44 engine design that development continued through the 1980s, despite the absence of any launch order or production application. Two partnerships with two successive manufacturers failed to result in a production aircraft, Cessna jumped on the light jet concept and placed a substantial order for FJ44 engines. In 1992, the Cessna CitationJet, equipped with a pair of now FAA-certified FJ44-1A engines, became the first production aircraft equipped with Williams engines. Compared to its predecessor, the Citation 500, the FJ44s enabled the CitationJet to go nearly 40% faster and 15% farther at an identical mid-cruise weight, all while using 17% less fuel—despite the FJ44 having a lower thrust output than the JT15Ds used on the first Citations. Needless to say, the FJ44 and the CitationJet series became a smashing success. To date, there are more than 2,500 Williams-powered CJ series aircraft in operation.

The FJ44 gave rise to a whole new class of general aviation aircraft and is regarded as one of the landmark engines in aviation history. The FJ44 has even been scaled down to create the FJ33 engine, which is used in very light jet category aircraft like the Cirrus Vision Jet. In total, Williams FJ series engines power over 3,000 business jets across the globe.