Unloading the rotor

[Aviator168]

Will unloading the rotor reduce drag? The Eurocopter gets its speed by unloading its rotor (slow it down a bit), and the two little wings take care of 20 to 80 percent of the lift. I am wondering if the same scheme can be used on gyroplanes.

 

[WaspAir]

Many have tried. Look up the CarterCopter.

 

[Aviator168]

The CarterCopter takes it to the extreme. In cruise flight, their rotor is totally unloaded, rpm is only there for rigidity. In the case of the Eurocopter X3, the rotor is unloaded to avoid drag from the advancing blade and retreating blade stall, and it only unloads a small percentage, https://en.wikipedia.org/wiki/Eurocopter_X³ I am wondering how much speed can be gain in a gyro if it is done in the X3 way.

 

[Vance]

The McCulloch J2 had stub wings for fuel tanks.

The Arrow copter and the American Ranger have stub wings for landing gear.

It is not a popular approach for reducing power required for a given airspeed.

 

[WaspAir]

Don Farrington told me he intended to add stub wings to a follow-on of the A&S18A, but his death ended all such plans.
My J-2, a side-by-side two place, was faster than the tandem 18A at the same weight with the same horsepower, and I always suspected the wings had something to do with it.

 

[Aviator168]

The 18A seems to have a higher thrust line and HS is at a small angle which can have a larger induced drag.

Aside from that. Can the rotational axis be normal to the air stream or even tilt forward a bit into the air stream? My understanding is the rotational axis has to tilt backward for autorotation to work.

 

[Vance]

The 18A seems to have a higher thrust line and HS is at a small angle which can have a larger induced drag.

Aside from that. Can the rotational axis be normal to the air stream or even tilt forward a bit into the air stream? My understanding is the rotational axis has to tilt backward for autorotation to work.

I have not been able to determine the center of gravity of a gyroplane without a double hang test.

In my opinion a gyroplane rotor is driven when the air is going up through the disk.

It may help you to read Chapter 16 in the Rotorcraft Flying Handbook; Aerodynamics of the Gyroplane.

https://www.ronsgyros.com/Gyro_Handbook.pdf

For me; part of the allure of a gyroplane is its simplicity.

I find that trying to expand the gyorplane flight envelope often is in conflict with simplicity.

Aviation is a compromise and some other type of aircraft may better suit your mission if you want more speed or more efficiency than a gyroplane provides.

 

[WaspAir]

The 18A seems to have a higher thrust line and HS is at a small angle which can have a larger induced drag.

You are making some unwarranted assumptions about pitch attitude in flight for those aircraft.

 

[bryancobb]

If you want to fly fast...choose a fixed wing. If you want to fly fun and slow...choose a fling wing. They are like oil and water, starting at the Radio Control Flying Field. They get on each others' nerves and get in each others' way. That will never change.

 

[Aviator168]

Gyroplanes have the potential to replace bush FWs if they are made easier to takeoff/land on un-even terrain.

 

[WaspAir]

Unlikely, given their respective payloads. I've seen bush planes in Alaska take off with more stuff strapped on and packed in than you can imagine. Bush aircraft are like trucks and get filled to the gills in ways that would ground a gyro.

The Husky has a 975 pound useful load, as one example,

 

[Aviator168]

I was referring to those LSA bush planes. For a rotary craft, only a heli can compete with the Husky; but nothing beats the econony of a FW. For an UL, a gyro is easier to build than a FW as a FW UL needs a very large wing to meet its stall requirement.