To: Flight Safety. .. .The helicopter concept you describe actually flew and it wasn’t the Djin. The helicopter I am referencing was designed and flown by Mr. Maurice L Ramme of Seattle, Washington. Mr. Rammes’ entry into the field of rotary wing aircraft was the Hoppy-Copter a one-man coaxial helicopter. That design was sold to an English firm for further development and eventual marketing. It died a slow death.. .. .He then developed a tip jet helicopter, which actually flew. The company name was Monte-Copter, Inc. The company was named for Mr. Rammes’ son Monte who still lives in Seattle. The helicopter used a controllable vane behind the turbine exhaust for directional control. The concept was proven and then he and his design team developed a much larger version. To save construction cost the fuselage structure was that of a Westland 30 which by that time went out of production. The helicopter had twin booms and two jets for power. I believe the jets powered two turbines, which developed the pressure for the tip jets, and the jet exhaust went down the boom, which provided some thrust, and vanes to effect directional control deflected the thrust.. .. .The design was completed but there were funding problems. This was further complicated by the untimely death of Mr. Ramme.. .. . . .The most unique design element was the blade. Their design was such that two men in less than an hour could assemble them and as difficult as it might seem the blades could not stall. The design of the blades was offered to all of the helicopter manufacturers and to the US Military but for their own reasons the design was rejected.. .. .The prototype could be ground taxied and was highly maneuverable on the ground as well as in the air. On the ground the blades would not turn and the jet efflux was the propelling force. The last time I saw the prototype it was in the front yard of the Ramme residence covered by a tarp and was being over grown by small trees.. .. .I JUST REMEMBERED: Aside from the tips being blown the upper surfaces of the blades were also blown.. . . . <small>[ 17 March 2002, 19:28: Message edited by: Lu Zuckerman ]</small>