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Tiltrotor Test Rig

Graphic of TTR

For a sense of scale, the rotor is 26 feet in diameter and the rotor hub is 20 feet above the test section turntable.

The Tiltrotor Test Rig (TTR) is a NASA project, joint with the Army and Air Force, to develop a new, large-scale proprotor test system for the National Full-Scale Aerodynamics Complex (NFAC). TTR is designed to test advanced proprotors up to 26 feet in diameter at speeds up to 300 knots. This combination of size and speed is unprecedented and is necessary for research into 21st-century tiltrotors and other advanced rotorcraft concepts TTR will provide critical data for validation of state-of-the-art design and analysis tools.

Bell Helicopter Textron and Triumph Aerospace Systems designed and manufactured the TTR and supporting equipment, including a calibration rig, under NASA contract. The U.S. Army and Air Force are contributing funding and support. Additional funding was provided under the American Recovery and Reinvestment Act.

The TTR is designed for use in both the 40- by 80- and 80- by 120-Foot Wind Tunnels. The TTR is a horizontal axis rig and rotates on the test-section turntable to face the rotor into the wind at high speed (300 knots), or fly edgewise at low speed (100 knots), or at any angle in between. The TTR has four electric motors capable of 5000 hp total––enough to drive proprotors far more capable than any currently in existence.

The TTR is designed to accommodate a variety of rotors. A 26-ft diameter research rotor (shown in the figure) is installed for the first test. For maximum accuracy, rotor forces are measured by a dedicated balance installed between the gearbox and the rotor. Rotor torque is measured by an instrumented drive shaft.

Update: In August 2018, the TTR reached 273 knots max airspeed (current NFAC limit). This is the highest airspeed ever achieved by a full-scale proprotor in any wind tunnel.

Summary of TTR design capabilities:

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  • TTR in the news:

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  • NASA's Tiltrotor Sets Wind-Tunnel Record for High-Speed Proprotors

Photo Archive


 

TTR Overview Presentation


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Video Archive


 

Video of the TTR lift onto calibration stand, Sep. 2012


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Video of the TTR lift onto calibration stand, Oct. 2014


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