The structural use of fibre composites in helicopters, both for primary and secondary structures, has been recognised for some time. In 1964, Westlands developed a glass fibre composite tail boom and tailplane for the Wasp helicopter (Fig. 1) and the results were encouraging. The non-corrodable structure of the glass composite is considered a great advantage, especially for Naval helicopters. Strength testing of the tail boom was successfully completed with a weight of the component close to the existing metal tail boom, but resonance testing showed that a small additional weight was necessary to meet the stiffness requirements. The tailplane in glass fibre composite showed an appreciable saving in weight and after satisfactorily completing static and fatigue testing, one is now flying on a Service aircraft.