The Honeywell TPE331 (military designation: T76) is a

turboprop A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Fuel ...

engine. It was originally designed in the 1950s by

Garrett AiResearch Garrett AiResearch was a manufacturer of turboprop engines and turbochargers, and a pioneer in numerous aerospace technologies. It was previously known as Aircraft Tool and Supply Company, Garrett Supply Company, AiResearch Manufacturing Compa ...

, and produced since 1999 by

Honeywell Aerospace Honeywell Aerospace is a manufacturer of aircraft engines and avionics, as well as a producer of auxiliary power units (APUs) and other aviation products. Headquartered in Phoenix, Arizona, it is a division of the Honeywell International conglome ...

. The engine's power output ranges from .

Design and development

designed the TPE331 from scratch in 1959 for the military. “Designed as a 575-horsepower engine it was not a scaled-down version of a larger engine, as competitors were offering.” The TPE331 originated in 1961 as a gas turbine (the "331") to power helicopters. It first went into production in 1963. More than 700 had been shipped by the end of 1973. It was designed to be both a

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust ...

(TSE331) and a turboprop (TPE331), but the turboshaft version never went into production. The first engine was produced in 1963, installed on the

Aero Commander Aero Commander was an aircraft manufacturer formed in 1944. In subsequent years, it became a subsidiary of Rockwell International and Gulfstream Aerospace. The company ceased aircraft production in 1986. History Aero was formed in Culver City, ...

in 1964 and put into production on the Aero Commander Turbo Commander in June 1965.

Performance

The 715 shp TPE331-6 used in the

Beech King Air The Beechcraft King Air is a line of American utility aircraft produced by Beechcraft. The King Air line comprises a number of twin-turboprop models that have been divided into two families. The Model 90 and 100 series developed in the 1960s ...

B100 have a 400-hr. fuel nozzle cleaning interval, 1,800-hr. hot section inspection interval and a 5,400-hr.

time between overhaul Time between overhauls (abbreviated as TBO or TBOH) is the manufacturer's recommended number of running hours or calendar time before an aircraft engine or other component requires overhaul. On rotorcraft, many components have recommended or ma ...

; approval is possible for 3,000-hr. HSIs and 6,000-hr. overhauls and engine reserves are cheaper than for the PT6A.

Variants

Military variants (T76)

;T76-G-2: ;T76-G-4: ;T76-G-6: ;T76-G-8: ;T76-G-10: ;T76-G-12: ;T76-G-12A: ;T76-G-14: ;T76-G-16: ;T76-G-410: ;T76-G-411: ;T76-G-416: ;T76-G-417: ;T76-G-418: ;T76-G-419: ;T76-G-420: ;T76-G-421:

Commercial variants (TPE331)

Applications

Fitted with TPE-331s as a replacement for their original engines

Specifications

References

Bibliography

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External links

TPE 331 Cost Protection Programs

TPE 331 Engine Conversions

Power and fuel flow versus altitude and speed
for version 10.
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