To: John Bicker
The operative word(s) is / are Hughes Helicopters. The DARPA program took place in the early 1970s during the design of the Apache. Hughes constructed a five blade main rotor and the X tail rotor that was to be used on the Apache. It gave Hughes the opportunity to test the new tail rotor design before it flew on the apache and the government financed design and testing paid for most of what was required for certification. Although the designs of the tail rotor were different the concept was the same. After tweaking the helicopter and the engine it could fly overhead at 500 feet AGL and you could only hear a slight “whoosh”.
After the helicopter finished the testing it disappeared most likely to go to Vietnam.
