The CHAIRMAN, in opening the meeting, said that it was a pleasure to welcome the first lecturer of the 1958/59 season Mr Gerstenberger, who was Chief of Dynamics at the Sikorsky Aircraft Division of the United Aircraft Corporation, Bridgeport and Stratford, Connecticut, would be discussing the equipment necessary for the all-weather operation of helicopters

The Association was grateful to Mr Gerstenberger and to his Company for making available the benefit of their considerable experience in this field, and they were to be congratulated on having successfully evolved very reliable systems equipment, especially in their latest machine, the HSS-1N, of which Mr Gerstenberger would be speaking this evening

A method for predicting the flutter boundaries of a helicopter rotor blade is developed which is intended to provide

1. (a) an illustration of the effects of fundamental characteristics of the blade on the flutter boundaries, e g, mass axis location, flexural axis location, stiffness of control circuit, etc

2. (b) a basic approach which may be developed and expanded to provide more detailed representation of any particular blade problem For example, in addition to giving the flutter boundaries for the blade, the equations in the form presented could be used to determine the response of the rotor blade to force distributions which are simple harmonics of the rotor angular velocity Another example is given at the end of this report in which the familiar blade resonance diagram is obtained for the torsion and flapping modes considering dynamic and stiffness properties only, and then again for the blade including the effect of aerodynamic damping