Allison Engine Company

Allison Engine Company. Founded in Indianapolis by automotive pioneer James A. Allison, the company evolved from a specialist in World War I Liberty L-12 engine repair into a preeminent designer and manufacturer of aircraft engines and gas turbines. Its technological innovations, particularly in the field of turboprop and turboshaft engines, powered a vast array of military and civilian aircraft, leaving an indelible mark on aviation history. The company's legacy continues under the ownership of Rolls-Royce Holdings.

History

The company's origins trace back to the Indianapolis Speedway Team Company, established by James A. Allison to support racing at the famed Indianapolis Motor Speedway. During World War I, the facility was repurposed to overhaul Liberty L-12 engines for the United States Army Air Service. Following the war and Allison's death, the assets were acquired by Fisher and Lawrence Bell, leading to its incorporation in 1929. A pivotal moment came in 1941 when the United States Army Air Corps selected its V-1710 engine to power the Lockheed P-38 Lightning and other frontline fighters. Post-World War II, the company shifted focus to the emerging field of jet engines, developing America's first turboprop engine, which entered service on the Convair XP-81.

Products

The company's product portfolio was defined by several landmark engine families. The liquid-cooled V-1710 piston engine was its first major success, powering aircraft like the Curtiss P-40 Warhawk and North American P-51 Mustang. Its transition to gas turbines produced the influential T56/501 series of turboprop engines, which became the propulsion system for the Lockheed C-130 Hercules and Lockheed P-3 Orion. In the turboshaft category, the Model 250 engine achieved widespread use in helicopters such as the Bell 206 and MD Helicopters MD 500. For business jets, the Model 250 was adapted into the 250-C18 turbofan, used on the Cessna Citation I.

Military applications

The company's engines have been integral to United States Armed Forces operations for decades. The T56 turboprop remains the enduring powerplant for the Lockheed C-130 Hercules fleet and its derivatives like the Lockheed AC-130. The Model 250 turboshaft engine powers a vast array of military helicopters, including the Bell OH-58 Kiowa and the Sikorsky S-70. Earlier, the V-1710 engine was crucial in World War II, propelling the Bell P-39 Airacobra and early models of the North American P-51 Mustang. The company also developed the TF41 turbofan for the LTV A-7 Corsair II.

Civil applications

In the civilian sector, the company's engines enabled new paradigms in regional and executive travel. The T56/501 series engine found a major market in the Lockheed L-188 Electra turboprop airliner. The lightweight, reliable Model 250 turboshaft became the global standard for light utility and training helicopters, such as the Bell 206 JetRanger and the Eurocopter EC135. Its turbofan derivatives powered early business jets like the Cessna Citation I and the Gates Learjet 25. The company also provided industrial gas turbines for power generation and pipeline applications.

Corporate history and ownership

After years as a division of General Motors, the company was sold to the investment firm Clayton, Dubilier & Rice in 1993. It was subsequently acquired by Rolls-Royce Holdings in 1995, a move that significantly expanded the British firm's footprint in the United States defense market. The operations were fully integrated into Rolls-Royce North America, with the Indianapolis site becoming a key center for engineering and manufacturing. Today, the legacy product lines, including the T56 and Model 250, continue to be supported and upgraded under the Rolls-Royce brand.

Category:Aircraft engine manufacturers of the United States Category:Companies based in Indianapolis Category:Rolls-Royce Holdings