Hmmm...interesting.... .. .Crab, I thought of that too, it is a concept very similar to the Notar. However I thought it might have an advantage in that there would be no Coanda slots, and thus none of the wind direction problems that Nick referred to in the "MD600" thread. I also thought it might be more efficient than the NOTAR fan.. .. .TC, that's interesting. Somehow I thought there would be more energy in the jet efflux than there appears to be.. .. .To the others, all of the flying helicopter examples given seem to be either rotor jet tipped or counter-rotating examples. Both basic styles have low energy airframe yaw requirements. This also suggests that the energy available in the jet efflux may not be enough to provide the anti-torque required in a standard turbine helo.. .. .(edited for typos). . . . <small>[ 18 March 2002, 01:48: Message edited by: Flight Safety ]</small>