Williams International is the world leader in the development, manufacture and support of small gas turbine engines.
The privately owned company operates R&D (research and development ) and R&O (repair and overhaul) out of their headquarters in Pontiac, Michigan.
As can be seen from the table below, Williams International engines are a popular option among smaller jet aircraft.

Founded in 1955, Williams has expanded its development, test, production, and product support capabilities to create a large, versatile organization with the capacity to meet growth objectives in aviation, industrial and military markets.
As a privately owned endeavor, the vision stays focused, communication is straightforward, decisions are made quickly, and efforts are concentrated efficiently.
The following Williams International engines are those that power private jets – both past and present.
Engine Model | Aircraft |
---|---|
FJ33-4A-19 | Cirrus Vision Jet SF50 |
FJ44-1AP | Cessna Citation CJ1 |
FJ44-1AP | Cessna Citation CJ1+ |
FJ44-1AP-21 | Cessna Citation M2 |
FJ44-2A | Beechcraft Premier I |
FJ44-2A | Beechcraft Premier IA |
FJ44-2C | Cessna Citation CJ2 |
FJ44-3A | Cessna Citation CJ3 |
FJ44-3A | Cessna Citation CJ3+ |
FJ44-3A-24 | Cessna Citation CJ2+ |
FJ44-3AP | Nextant 400XT |
FJ44-3AP | Nextant 400XTi |
FJ44-4A | Cessna Citation CJ4 |
FJ44-4A | Pilatus PC-24 |
Williams International’s high-performance, high-power engines are reliable, time-tested, require less maintenance due to a simple, rugged design, operate in the harshest environments, and are fuel-efficient.
The engines that are currently bolted to these private jets date as far back as the year 2000 with the FJ44-1AP engines powering the Cessna Citation CJ1.
Since then, Williams International have been continuously developing their engines, making them lighter and more fuel-efficient.
Williams International primarily focuses on smaller engine applications. For example, VLJs such as the Cirrus Vision Jet and Cessna Citation M2. However, aircraft as large as the medium-sized Pilatus PC-24 is powered by Williams International engines.
According to Williams, “FJ33/FJ44 engines are backed by the best customer service in the industry – over the past 21 years Williams customer service has outscored all competitors in surveys of owner-operators, scoring 5% higher than the closest competitor. Williams’ engine maintenance plan – called Total Assurance Program (TAP Blue) – offers coverage no competitors can match – even including repair of foreign object damage (FOD) and incorporation of all service bulletins.”