My Helicopter List (Selection)
Helicopters:
Husky-22-Intermeshing-rotors-synchropter
Compound Helicopters
A compound helicopter is a rotary-wing aircraft that uses an additional system, such as fixed wings, a pusher propeller, or a ducted fan, to provide forward thrust, which offloads the main rotor during forward flight and allows it to be slowed. This design increases maximum speed and efficiency compared to a conventional helicopter by providing auxiliary lift and propulsion, enabling it to achieve significantly higher speeds, sometimes approaching those of fixed-wing aircraft.
Auto Gyros
An autogyro (from Greek αὐτός and γύρος, "self-turning"), gyroplane or gyrocopter, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. A gyroplane "means a rotorcraft whose rotors are not engine-driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving; and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system." While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate. Forward thrust is provided independently by an engine-driven propeller.
Wikipedia
Experimentals
Levitator-1-3
The bladeless chopper - imagined by Win's Wings
Experimental-wing-tip-jet
inspired by HILLER YH-32 HORNET, concept helicopter with a wing tip jet -Unfinished test project