Airspeed Hardrada - Airborne Troop Gyrocopter

[Scotaidh]

I don't see any reason you couldn't have full-size wings as well as rotor blades.  A brake on the rotor would allow the wings to work usually for towing purposes.  Just before tow-release the pilot releases the rotor brake.  As the rotor bites, drag would increase, causing the craft to rise.  That's when the pilot releases the tow-rope and picks his landing spot.

The wings would reduce the usefullness of the rotor, of course, so one would land a bit harder than rotor-only, but still not as hard as a wings-only landing.  I think it'd be a good compromise.

High aspect-ratio wings would work best.  Anyone up for "rotodyning" a B-24? 

[Tophe]

I love it!

[Dizzyfugu]

Cool, this is working very well.

[tigercat]

Looking very smart

[Old Wombat]

Of course the Real World can provide some insight:

Chapter 6

Conclusion

The use of a gliding autogyro as a delivery vehicle in precision airdrop missions has been shown to be a good option in fulfilling modern accuracy requirements. Several developments in this work have  shown this feasibility.
Simulation: A six degree of freedom simulation was derived based on rigid body dynamics and rotor aerodynamics including blade element and momentum theory. Although simulations with higher fidelity are  possible, Sections 2.4 and 3.2 showed the validity of the simulation in both a trim and dynamic sense by comparison with other work.
Controller: A controller was designed to guide the autogyro to the target location. This controller utilized a classical, multiple loop closure technique, with a new nonlinear guidance law for path following. A path generating algorithm was also created that utilizes known constant wind  speed to maintain a constant nominal glide slope throughout the mission.
Estimation: The extended Kalman filter with continuous propagation and discrete measurement updates was used to estimate the state information needed by the controller. Simulation results show an impressive accuracy of about 5 ft, even  in the face of large wind disturbances.

This project is still in development, and several steps must be taken to ensure success of the final design of the autogyro system.
Path Generation: The assumption of a constant wind profile with altitude is not very realistic. Assuming a constant rate of descent, the path planning algorithm can be modified to use the average wind speed as an input. However, a wind estimation and path regeneration scheme must be created to include the effects of time-varying wind.
Sensor Suite Selection: The particular sensors to be used must be selected to tune the parameters of the estimator. Additionally, the relative importance of each sensor must be determined.
Landing: Even though final position accuracy is good, the rate of descent maybe too high for different payloads and applications. This could be achieved by an appropriate flaring strategy, either by backwards tilting of the rotor and trading forward energy for vertical energy, or by adding a variable collective control that would allow trading rotor rotation rate for thrust increase. In each case, an energy necessary for flight is used to provide a momentary decrease in descent speed. A challenge would be to time the landing for a minimum descent speed while maintaining position accuracy.
Startup and Transition: An autorotating rotor in equilibrium will maintain its rotation rate, but starting the rotor can be an issue. The problem is essentially breaking a stall barrier on the rotor blades. Also, the transition from vertical descent to forward glide will pose additional challenges due to the vehicle nonlinearities between these two trim conditions.

https://dspace.mit.edu/bitstream/handle/1721.1/32456/61751366-MIT.pdf;sequence=2

[NARSES2]

The wings would reduce the usefullness of the rotor, of course, so one would land a bit harder than rotor-only, but still not as hard as a wings-only landing.  I think it'd be a good compromise.

Get rid of them using explosive bolts ? It's the type of thing you can see the RAE at Farnborough playing with during WWII.

[PR19_Kit]

I've always said it's difficult to beat a Kalman filter with continuous propagation and discrete measurement updates. 

That paper demands some serious reading, sometime.......maybe........ 

But MIT is about 60 years behind Buzzbomb's idea. 

[Scotaidh]

The wings would reduce the usefullness of the rotor, of course, so one would land a bit harder than rotor-only, but still not as hard as a wings-only landing.  I think it'd be a good compromise.

Get rid of them using explosive bolts ? It's the type of thing you can see the RAE at Farnborough playing with during WWII.

Well - perhaps.  I feel there's a fairly high risk of the blown-off wing-bits impacting the rotor blades ... and I'm not comfortable with that. 

[Glenn Gilbertson]

Great idea and model!

[NARSES2]

The wings would reduce the usefullness of the rotor, of course, so one would land a bit harder than rotor-only, but still not as hard as a wings-only landing.  I think it'd be a good compromise.

Get rid of them using explosive bolts ? It's the type of thing you can see the RAE at Farnborough playing with during WWII.

Well - perhaps.  I feel there's a fairly high risk of the blown-off wing-bits impacting the rotor blades ... and I'm not comfortable with that. 

Very much so, but that's the type of thing RAE would spend 18 months or so working on ways to get around, and then decide it wasn't really a goer