Twin Commander logo aerial shot of Twin Commander airplane


TPE 331-10T Twin Commander



Introduced in 1965, the 575 shp 331 engine evolved into the -1 Century series engines rated at 715 shp. Still occupying the same frame size, the compressor was uprated in 1969 to create the first member of the 840 SHP family, the TPE 331-3. The TPE 331's evolution continued a year later with the introduction of the flat-rated versions of the -3, the -5 the -6. The TPE 331-5 was the engine placed on the turbine Aero Commander. In the mid -70s, the -8 engine appeared. While the takeoff thermodynamic rating only increased modestly over the 840 SHP series, the altitude performance was greatly enhanced. The increased demand for altitude performance fostered the development of the 1,000 shp -10 engine, certified in 1978. A product of evolution, the TPE 331-10T engine has earned a reputation of significant performance and reliability. The engine has been installed on a variety of executive, regional, utility, agricultural and military aircraft throughout the world.

The most popular and highest performing conversion using -10T power has been the Twin Commander 690A, B, C, & D models.

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The -10T Twin Commander Hallmark

  • 300+ KTAS
  • Full power to 16,000 feet
  • 3,500 fpm initial rate of climb/Greater than 2000 fpm to FL200
  • 12 minutes to FL290
  • Increased fuel efficiencies
  • Increased range

Prototyped in 1993, and debuting during the 1993 NBAA show, the -10T Twin Commander matches any aircraft legendary for its performance to an even higher performing engine. The result is a performance conversion so popular, over 170 -10T Twin Commander aircraft are flying.

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Aircraft Performance
Increasing operator capabilities and margins of safety.

Unequaled in its Class
Today's highest performing, most desirable turbo-prop in its class.

A protected investment, reduces annual operating costs. Over 79% reduction in scheduled HSI/GBI maintenance.

Today's technology and efficiencies—modular design.

Flexible intervals and multiple TBO options.

Retrofit Options
Customized to meet an operator's current needs.

A warranty to match an operator's overhaul choice.

Service and Support
Worldwide, on demand factory support from Twin Commander and Honeywell.

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The availability of additional horsepower at all flight levels translates into markedly improved aircraft performance in virtually all flight missions from sea level to cruise altitudes. The ability to climb faster to more fuel efficient altitudes provides an additional benefit on even short stage lengths that might have formerly dictated lower cruise altitudes.

Speed: 300+ KTAS
Climb: 717.5 shaft horsepower to 16,000 feet. 3,500+ fpm through 20,000 feet.

Your -10T Commander is capable to FL 230 in 8 minutes, or FL 290 in only 12 minutes from brake release. This remarkable climb performance gets you above weather fast, keeps you above slower traffic, and departs high, hot locations with unmatched capability.

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Aircraft Performance Flight Test Data
Flight Test Data (690A) TPE331-5 TPE331-10T
Thermodynamic Shaft Horsepower 840 minimum 1,000 minimum
Flat Rate Torque To 6,000 ft 16,000 ft
Cruise Speed 276 KTAS 300+ KTAS
(ISA, 9,000 lb, 96%, 20,000 ft)

Unequaled In Its Class Measured against other turboprops in its class, -10T powered Twin Commanders are unrivaled in overall speed, climb and operating costs.

  Flight Test Data Flight Test Data Flight Test Data Flight Test Data
  Garrett TPE 331-10T Garrett TPE 331-8 Pratt & Whitney PT6A-21 Pratt & Whitney PT6A-135
Shaft HP 1,000 625 550 620
Common TBO (Hrs) 5,000 3,000 2,706 2,940
Takeoff Perform SL ISA BFL (ft) 1,833 2,465 2,706 2,940
Max Range (N-Miles) (NBAA IFR Reserves) 1,424 1,566 1,120 1,282
Climb (SL ISA MTOW) Normal (FPM) 2,824 2,435 2,003 1,750
Engine Out (FPM) 1,003 715 554 470
Normal Cruise TAS 300+ 287 240 255
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A decision for a -10T powered Twin Commander is a low risk, high return investment.

Increased Aircraft Value
An investment in the -10T conversion immediately translates into higher market value for Turbo Commander aircraft.

Reduced Hot Section Costs
Extended major inspection intervals reduce maintenance.

Improved Fuel Efficiencies
The -10T has shown up to 7% overall reduced fuel burn over -5.

2 Year Warranty On Turbine Components
Honeywell warranties are designed to meet your needs.

Factory Backed Program
A program backed by the engine and aircraft manufacturer guarantees maximum protection of your investment.

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TPE 331 -10T power on the 690 series Commander Aircraft means responsive, reliable flying. A geared propeller driven by a single-shaft power section utilizing dual centrifugal compressors and three axial turbines allows for a compact, low weight, and high power design.

High Technology Cooled Turbine Components
Effective cooling increases component life and reliability.

ITT Replaced By EGT
By virtue of replacing the ITT with an EGT system, -10Ts offer cost benefits through improved reliability.

Improved Thermodynamics
Due to its high thermodynamic rating, -10T engines will operate at less than 72% of rated power at full throttle operation.

The -10T's modular hot section components and factory-initiated enhancement programs result in lower maintenance costs. Additionally, -10T operators can count on reduced downtime by utilizing Honeywell & Twin Commander Aircraft LLC's Factory Authorized Service Centers.

Flexible Major Maintenance Intervals
Maintenance programs to fit an operators needs.

Factory Developed and Supported Aircraft STC
With over 170 conversions worldwide, the -10T powered Twin Commander is a proven design.

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The TPE331 -10T conversion program allows for two retrofit options, providing choices in converting Twin Commander aircraft.

Option 1: Overhaul and Modification
Developed for operators nearing overhaul expiration on the -5 engine. However, it may be accomplished at any point in the engine's life with resultant overhaul service bulletin modification standards and warranty benefits.

* Overhaul and Major Inspection Interval Options
  Option A Option B**
Hot Section
Hot Section & Gearbox
1,800 hrs.
3,600 hrs.
5,400 hrs.
2,500 hrs.
5,000 hrs.

Option 2: Engine Continued Time Modification
This option makes -10T engine performance available without waiting for the -5 engine to reach its schedule overhaul interval.

* Overhaul and Major Inspection Interval Options
  Option A Option B**
Hot Section
Hot Section & Gearbox
1,800 hrs.
3,600 hrs.
5,400 hrs.
2,500 hrs.
5,000 hrs.

* Desired overhaul option must be declared at the time of modification to allow for the appropriate log book entries to be accomplished.
** Greatest cost reductions

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Honeywell offers warranty options for -10T conversions.

Overhaul / Conversion
Twenty-four months from date of shipment or twelve months from date of initial operation whichever occurs first for defects in material and workmanship. Additionally, the turbine section will be covered for twenty-four months from the date of initial operation.

Continued Time/Conversion Warranty
Twelve months from date of initial operation on power section and gearbox for defects in material and workmanship; thirty days from initial operation on line replacement items. Additionally, the turbine section will be covered for twenty-four months from date of initial operation.

* Refer to Honeywell Engines Warranties for detail as applicable. Would You Like to Receive More Information on the Dash 10 Conversion?

Click Here to Request the "Dash 10" Interactive CD-ROM

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