Whirl Tower

Field Service

CTI’s state-of-the-art whirl tower for balancing helicopter blades is one of the largest, most capable balance stands in the country. Designed for testing main rotor blades that rotate either clockwise or counterclockwise, the bi-directional whirl tower provides CTI the capability to meet the balance requirements of any rotor blade manufacturer.

The whirl tower features two 3,000 shaft horsepower (shp) variable frequency drive induction motors for a peak rating of 6,000 shp in either direction. The tower’s 6,000 lb stainless steel rotor head enables CTI to spin three blades (typically a master blade and two test blades) weighing up to 500 lbs each. This easily accommodates even the largest blades flown on U.S. Marine Corps CH-53 heavy lift helicopters.

Currently in use, the whirl tower measures the dynamic and aerodynamic balance of a rotor blade by spinning it with a master blade traceable to the OEM primary standard. As the three blades rotate about the rotor head, a laser tracking system measures where the blades fly relative to one another, and precision load cells measure the pitching moment of the blades relative to one another. Adjustment of pushrod settings, tip weights and trailing edge trim tabs allow the operator to match the dynamic and aerodynamic behavior of the test blade to the master blade as closely as possible. This minimizes the required on-aircraft balance efforts and provides a level of interchangeability for fielded aircraft.


Mailing Address
Composite Technology Inc.
PO Box 610407
Dallas, TX 75261

Shipping Address
Composite Technology Inc.
1727 S. Main Street
DFW Airport, TX 75261

Phone: +1 972-456-6900
eFax: +1 972-456-0162
Email: CTI Customer Service
Email: Quality Inquiries

© 2015 Composite Technology Inc.