SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 11 - MAY 30, 2006

08 AIRCRAFT STABILITY AND CONTROL
Includes flight dynamics, aircraft handling qualities, piloting, flight controls, and autopilots.

For related information see also 05 Aircraft Design, Testing and Performance; and 06 Avionics and Aircraft Instrumentation.

20060013409 NASA Ames Research Center, Moffett Field, CA, USA

Performance, Loads and Stability of Heavy Lift Tiltrotors

Acree, Cecil W., Jr.; Johnson, Wayne; [2006]; 9 pp.; In English; AHS Vertical Lift Aircraft Design Conference, 18-20 Jan. 2006, San Francisco, CA, USA; Original contains black and white illustrations; Copyright; Avail.: Other Sources

Summaries of rotor performance are presented for a 124,000-lb Large Civil Tilt Rotor (LCTR) design, along with isolated-rotor and fully-coupled wing/rotor aeroelastic stability. A major motivation of the present research is the effect of size on rotor dynamics. Simply scaling up existing rotor designs to the vehicle size under study would result in unacceptable rotor weight. The LCTR was the most promising of several large rotorcraft concepts produced by the NASA Heavy Lift Rotorcraft Systems Investigation. It was designed to carry 120 passengers for 1200 nm, with performance of 350 knots at 30,000 ft altitude. Design features included a low-mounted wing and hingeless rotors, with a very low cruise tip speed of 350 ft/sec. The LCTR was sized by the'RC code developed by the U. S. Army Aeroflightdynamics Directorate. The rotor was then optimized using the CAMRAD II comprehensive analysis code. The blade and wing structures were designed by Pennsylvania State University to meet the rotor loads calculated by CAMRAD II and wing loads required for certification. Aeroelastic stability was confirmed by further CAMRAD II analysis, based on the optimized rotor and wing designs. Author

Tilt Rotor Aircraft; Aeroelasticity; Rotor Dynamics; Wing Loading; Rotary Wing Aircraft; Stability; Flight Characteristics; Helicopter Design

Source: NASA