NOTAR™ HYBRID COMPOSITE/METAL FAN BLADE

For the past ten years McDonnell Douglas Helicopter Company has been developing the NOTAR™ (No Tail Rotor) helicopter. At the start of the NOTAR™ Program, a metal blade and hub assembly were selected to supply the air for both the tail boom and the thruster. Though adequate for proving the viability of the NOTAR™ concept, as the program matured it became clear that the performance of the blade was not suitable for continued use and improvement in directional control would have to be made. Towards this end, an outside company was contracted in 1984 to design and fabricate an all composite fan blade that would be compatible with the existing hub. Though this was accomplished, the composite blades that were supplied failed. This paper will discuss the design changes of the all composite blade that resulted in the evolution of a hybrid composite/metal fan blade.