A piloted experiment was flown using the Institute for Aerospace Research Bell 205A variable stability helicopter. The experimental variables were the static and dynamic characteristics of a conventional center-mounted cyclic controller. The cyclic controller characteristics were changed by varying the mass and spring gradient to provide five basic cases, while for each case the dynamics of the stick were varied to provide critically damped, underdamped, and overdamped models. Two pilots were asked to fly a variety of tasks designed to exercise three fundamental modes of helicopter flight, high frequency stabilization, gross single axis tasks with off axis stabilization and simultaneous multi axis control. The stick sensitivity was adjusted in proportion to the spring gradient to give constant static sensitivity with respect to applied force. A first order filter was incorporated on an optional basis to reduce the command response bandwidth of the roll channel to the Level 1/Level 2 boundary of the ADS-33C criterion for divided attention operation. The results achieved indicate that cyclic stick characteristics are of considerably less importance than had been previously thought, that large values of overdamping can be tolerated even in low frequency sticks, but that underdamped sticks should be avoided especially if the resonant frequency of the stick is close to an undesirable and easily excited aircraft mode. There was a suggestion that a boundary based on undamped natural frequency also existed. The results did not support the contention that inertia alone is enough to specify an acceptable/unacceptable boundary for stick design.
Initial Study into the Influence of Control Stick Characteristics on the Handling Qualities of a Fly-by-Wire Helicopter
1991
13 pages
Report
Keine Angabe
Englisch
Flight characteristics , Bandwidth , Foreign technology , Fly by wire control , Stabilization , Aircraft , Gradients , High frequencies , Frequency stability , Controllers , Resonant frequencies , Aeronautics , Inertia , Control sticks , Controllability , Criteria , Roll , Helicopters , Dynamic characteristics , Bell aircraft , Boundaries
NTRS | 1982
Emerald Group Publishing | 1989
|NTIS | 1982
Helicopter Handling Qualities : Proceedings
TIBKAT | 1982
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