VAROC® Air Dynamometers

Portable Turboshaft Engine Testing in Any Climate

The VAROC Air Dynamometer has been used by military and commercial organizations throughout the world for over 25 years. It has established a new standard for testing turboshaft engines for helicopters, power generation and marine applications. Branches of the US military use the VAROC to test Apache, Black Hawk, and Chinook engines before they are reinstalled to help ensure the safety of the pilots and crew. Recently, the Swedish Navy purchased a VAROC to to help with their Visby Class Corvette, the first vessel in the world to have fully developed stealth technology.

The VAROC family of air-brakes, V35, V35/85, and V250, provide an accurate, easy-to-use, easy-to-maintain, compact, lightweight, and highly reliable test capability to measure the performance of turboshaft engines ranging from 50 hp to 18,000 hp.

V35 Dynamometer testing helicopter enginesConcepts NREC's V35 Dynamometer is configured for testing Helicopter engines in high altitude / low temperature conditions. The custom gearbox and pedestal style torquemeter are used to maximize drive-line performance.

V250 Dynamometer testing a T55 Chinook engine for the US ArmyConcepts NREC's V250 Dynamometer testing a T55 Chinook engine at one of the U.S. Army’s several indoor/outdoor facilities located around the world.

Our patented product design uses ambient air as the fluid medium, which provides significant advantages over other types of dynamometers, including water brakes. Some of the VAROC Air Dynamometer benefits are:

  • Can be installed in fixed test-cell installations or used in mobile field applications
  • Does not require extensive support equipment
  • Can operate in any climate 
  • No potentially hazardous materials produced, so no need for contaminated water remediation, etc.
  • Easy to operate & maintain

V35 dynamometer testing an Apache EngineConcepts NREC's V35 testing a T700 Apache Engine in the field.


Concepts NREC V35 Dynamometer testing a T58 Sea King Engine

V35 Dynamometer testing a T58 Sea King Engine at one of the U.S. Navy’s several indoor/outdoor facilities located around the world.

Varoc Air Dynamometer from Concepts NREC

Concepts NREC's V35 set up on the flight line for outdoor testing in the winter.

Learn More about Dynamometers in SpinOffs

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U.S. Patent Nos. 4744724, 5345827, 5426986. VAROC is a registered trademark of Concepts NREC