Reaction Drive Helicopter for DARPA Lift Challenge

A solution to the challenge of lifting a payload that weighs 4 times the ramp weight of the vehicle

Reaction Drive leverages thrust generators on individual rotors to eliminate the need for anti-torque measures

Whether by ducted air or gas jets at the tips, or by propeller systems mounted on the rotors, Reaction Drive helicopters have the advantage of employing all of the input power to lifting and transporting payload. Conventional helicopter designs often consume 10-15% of input power just counter-acting the torque that results from turning the main rotor. In principle, Reaction Drive helicopters are capable of lifting massive amounts of weight.
Massive Tip-Jet helicopter
Applicable Patent

Cyclo-rotor drive units do not suffer extremely short fatigue life of conventional propellers caused by gyroscopic precession forces

Conventional propeller systems used to propel reaction drive rotors are, in effect, gyroscopes which are forced to constantly precess as the main rotor system turns. Motor drive shafts and propeller blades are flexed twice per shaft rotation by the precession forces.
Tip-jet systems require the routing of fast, high-pressure, often high-temperature gasses through narrow rotor blades to the rotor tips to produce thrust. Some tip-jet systems even have had after-burning sections to augment thrust at the tips at the expense of extremely high fuel consumption.
Cyclo-rotors produce substantial thrust at high efficiency and low fuel consumption rates without excessive fatigue caused by gyroscopic precession forces.
Applicable Patent

A Reaction Drive Helicopter - Cyclo-rotor configured for the DARPA Lift Challenge and capable of 4+:1 payload ratio would look like this:
- 8 meter span
- 22 Kg OWE
- 2.49 Kgf/m2 disk loading
- 17.86 Kgf/KW power loading
- 5.6 L/hr fuel burn rate
- Cruise 12 m/s
(Current TRL ~4)