Evolution of the Honeywell TPE331

In the same year, TPE331 engines were installed on a Mitsubishi MU-2 demonstrator. It was a win-win arrangement, providing Mitsubishi with a demonstrator and giving Garrett the title of the fastest turboprop airplane engine at the time. The TPE-331 powered MU-2, a twin turboprop utility transport with short takeoff and landing (STOL) capability, earned FAA certification the following year.

The Garrett TPE331 was also selected for the Aero Commander, with the first flight of its prototype closing out the year on Dec. 31. Deliveries of the TPE331-43 powered Aero Commander Turbo Commander began in mid-1965.

The first commercial version of the Garrett TPE331 engine received its type certification from the FAA on Feb. 25, 1965, marking the first time Garrett AiResearch engineers had ever certificated the main propulsion engine for an aircraft. It followed the prior year’s significant milestones toward bringing Garrett’s first turboprop engine to market.

Garrett’s T76 engines powered the July 1965 first flight of a Navy counterinsurgency (COIN) aircraft called the OV-10A. The T76 was a military version of Garrett's TPE331 turboprop. Eventually more than 1,000 T76 engines were delivered for the OV-10, which saw heavy use between 1976 and 1992, especially during the Vietnam War. The selection of the Garrett TPE331 (T76) engine for this key military program was a significant turning point in the history of Garrett engines.

In the late 1960s, the U.S. Fish and Wildlife Service took advantage of the rugged engine for use on long-range patrols in the Arctic Ocean where conditions required the engine’s quick throttle response for shorter take-offs, good power-to-weight ratio and the ability to climb faster and cruise farther. In 1963, Garrett AiResearch merged with Signal Oil & Gas Company to become The Signal Companies. AlliedSignal merged with Honeywell in 1999.

In the 1980s, British Aerospace chose the engine for its Jetstream family of regional turboprops. And the Royal Air Force in the U.K. still utilizes the TPE331 engine on the Shorts Tucano, an aerobatic military training airplane. Nearly three decades after delivering its first TPE331-12 engine in 1984, Honeywell Aerospace shipped engine number 1,000 to Texas Turbine Conversions in March for installation on a Cessna Caravan utility aircraft. A 1985 merger with the Allied Corporation resulted in AlliedSignal. AlliedSignal merged with Honeywell in 1999.

Today, customers select the TPE331 engine as a retrofit for Cessna Caravans, de Havilland Canada Otters and other utility aircraft to boost their power and performance.

Most recently, Honeywell announced a contract to re-engine a fleet of Antonov An-2 bi-planes- 1946-era airframes that still see utility and agricultural service in very remote harsh conditions thus extending the lifecycle of these workhorses.

Honeywell’s TPE331-12B turboprop engine will power India’s new military trainer prototype, the Hindustan Aeronautics Limited (HAL) HTT-40 basic military trainer.

Honeywell engineers continue to collaborate with aircraft manufacturers across the aerospace industry to ensure that the TPE331 will meet the needs of the aviation community for the next 50 years.