Results of an investigation in the Langley full-scale tunnel of a small stand-on type helicopter in low-speed forward flight are presented. The rotor blades were fixed at the roots and had preset coning angles. The results include measurements of forces and moments and staticstability derivatives determined from these measurements.nThese tests indicate that forward speed of the helicopter would be limited to approximately 17 knots because of large stabilizing pitching moments. Pitching moments and static-stability derivatives for the isolated rotors as deduced from the helicopter measurements are compared with rigid-rotor theory. For the isolated rotor, the pitching moments and the static-stability derivatives with respect to angle of attack may be estimated by means of rigid-rotor theory provided that a linear longitudinal-inflow variation is considered.
展开▼
