Let me put my 2c in on Cartercopter:
The concept is cool, the team is fired up and making things work, but there is a long long way to go. The speed/power/mach barrier is a tough one, indeed. The ABC has been in autogyro mode to about 300 knots at moderate altitude, and I think about 250 knots at 25000 feet, so the Cartercopter certainly plans to expand the rotory wing experience envelope.
The team will work these things out, but not easily, as rotors do not like going above mach 1 because the change in blade pitching moment for the advancing blade makes the tips go wild on the upwind portion, then they get into full stall on the downwind portion until they accelerate to the reverse flow condition. The massive lift imbalance will challenge the rotor-cyclic and aileron controls, as well as the structure and the vibration environment. For an autogyro, the cycling between stall and Mach 1 can occur about 3 times a second, so the blades take an awful pounding, the vibrations are very high, the lift they produce is minimal (thus the wings), and the drag they produce is quite high.
The real promise should not be stated as a speed at an altitude, it should be stated as a full mission capability for a price. For example, "with an XXX engine, and a price of yyy to purchase, the Cartercopter can take 4 170 lb people from a field length of zzz feet at sea level, standard temp, climb to ppp feet, cruise at qqq knots using rrr gallons of fuel per hour, and travel sss nautical miles with ttt minutes of reserve fuel. It will be certified as a normal category gyroplane for both IFR and VFR flight." Now that is a promise we can sink our teeth into.
Anyone can make the Holland Tunnel go 400 knots at 45,000 feet, given enough explosives.
None of the above is intended to dampen the wonderful ardor of the Cartercopter team, they have a beautiful aircraft, and a great idea. I have worked on several aircraft from ink-on-paper to certification, and it is a heady thing. I would envy the Cartercopter folks, were I not up to my gills in the S-92!!
[ 04 November 2001: Message edited by: Nick Lappos ]
[ 04 November 2001: Message edited by: Nick Lappos ]