Skip to main content

Results of Preliminary Studies of a Bearingless Helicopter Rotor Concept

Buy Article:

$30.00 plus tax (Refund Policy)


A new helicopter rotor concept, designed to reduce complexity and costs through the elimination of all hinges and bearings, has been under development for several years at United Aircraft. The ability to achieve a true bearingless rotor is made possible through the use of the unique nonisotropic properties of fiber reinforced composite materials. Specifically, the low torsional stiffness of unidirectional composites allows the root section of a helicopter blade to be elastically twisted to achieve blade pitch control while maintaining the necessary bending stiffness. This paper presents the results of preliminary studies conducted to evaluate the feasibility of this concept. Emphasis is placed on the fundamental design features and the characteristics of composite materials and how they relate to the control and operation of the rotor. Presented also are results of composite material fatigue tests, wind tunnel tests of a dynamically scaled model rotor, analytical results of a full‐scale design, and an aeroelastic analysis evaluating the rotor dynamic stability characteristics.

Document Type: Research Article


Affiliations: Aerodynamics Section, Fluid Dynamics Laboratory, United Aircraft Research Laboratories, East Hartford, Connecticut

Publication date: October 1, 1972

More about this publication?
  • The Journal of the American Helicopter Society is the world's only scientific journal dedicated to vertical flight technology. It is a peer-reviewed technical journal published quarterly by AHS International and presents innovative papers covering the state-of-the-art in all disciplines of rotorcraft design, research and development. (Please note that AHS members receive significant discounts on articles and subscriptions.)

    Journal subscribers who are AHS members log in here if you are not already logged in.

    Authors can find submission guidelines and related information on the AHS website.


Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more