Helicopter afterburners??

Question

why dont they use afterburners on helicopters since they cant make em faster due to the retreating blade stall?

Answer 1

If you used an addition engine to propel the craft to a high speed then you could in fact destroy the Blades in the process. Lockheed tried this in the mid 60's using a pusher prop on the AH-56 Cheyenne.  The project suffered was canceled when the rotor on one prototype hit the fuselage and killed the pilot. Previous experiments with Hybrid Helo have all resulted in the same thing Rotor Instability at high speeds.

Basically the Helo's gotten bout a fast as it's gonna get.

Answer 2

what the h**l would an afterburner do? how would that overcome the effects of retreating blade stall? i don't have the time, somebody else here may, to conduct a course on helicopter aerodynamics for you. suffice to say that if you do learn the basics, you'll wonder how you could have asked such a question.

Answer 3

They have made experimental models that incorporate additional propulsion:

http://en.wikipedia.org/wiki/Bell_533

http://www.aviastar.org/helicopters_eng/...

http://www.aviastar.org/helicopters_eng/...

http://en.wikipedia.org/wiki/Sikorsky_X2

You might be able to supplement thrust with an engine, and lift with little wings, but retreating blade stall will always limit helicopter airspeeds. You can't change that. Besides, the additional weight of the extra propulsion and fuel would negate much of your gains. If you really want to go faster, you will have to get away from helicopters and move into hybrids like the V-22, or airplanes.

Read about dissymmetry of lift and retreating blade stall here:

http://www.dynamicflight.com/aerodynamic...

http://www.dynamicflight.com/aerodynamic...

"Some military choppers do actually have a small jet auxiliary motor for quick "In and Out" missions"

I have no idea what he is talking about here, unless he is thinking of some of these prototypes.

Answer 4

Some military choppers do actually have a small jet auxiliary

motor for quick "In and Out" missions, but you won't find them on the civilian or commercials.