This short talk describes the manufacture of the metal rotor blades now going into quantity production for the S 51 and S 55 Helicopters at the Westland Aircraft Works These blades are a Sikorsky development so that there are many details both of design and construction which I am not at liberty to discuss On the other hand I hope to give a general indication of the way in which they are made, and of the scale of facilities which are available They are the first all metal helicopter main rotor blades to go into quantity production outside the United States

The backbone of the blade is an extruded light alloy spar which begins life as a billet in the extrusion presses at Messrs Birmetals Since the blades of the S 55 Helicopter use the same type of extrusion as the smaller S 51 blades, in future all extrusions will be delivered to us in the longer length and will be cut down for the manufacture of S 51 spars Each extrusion contains two shear webs inside the main contour and these run the entire length of the spars