You are all aware of the problems associated with the title of this lecture and, m order to avoid overlapping with Mr Hafner, I shall limit my part to the work that has been carried out on the Skeeter

In many respects the helicopter resembles an aircraft engine unit, and it therefore suggests itself that the routine method of testing engines should be applied to the helicopter Indeed at the beginning of 1951, a draft proposal to this effect was put forward, and is as follows

• (1) The aircraft should be tested for functioning on the ground followed by the strain gauging of its transmission, control and rotor systems During the strain gauging a complete range of flight control should be covered

• (2) Records made of these tests should be examined for any undue stress levels and stress oscillations