Rotor Behaviour:

[Charles W.]

Anyone here have any experience with gimble head rotor systems?

 

As I understand the behaviour of a gimble head rotor system if you increase airspeed in level flight ( Gyroplane ) the Rotor Thrust Vector will change due to the advancing blade increasing Aof A and retreating blade will have a decreased Aof A resulting in flap back of the rotor disk as speed increases. So the net result will be an increase of rotor disk Aof A.

 

Have I got this correct?

 

Reverend Chas W.

[CTD]

You should have it correct.

 

I don't know squat about gyroplanes, except to avoid them, but a normal rotor would behave as you describe.

[Charles W.]

Yes CTD, the reason I am delving into rotor behaviour in gyroplanes is because in 1991 I decided to add Gyroplanes to my flight school to sort of make it interesting, I already had a R22 on floats so thought I would add gyros.

 

Well it turned out to be a very long road to learn about gyroplane flight.

 

I wrote the US commercial gyroplane exams and took my training in a McCulloch J2 certified gyroplane. then passed the FAA flight test.

 

Once I was the holder of a U S Commercial Gyroplane Licence I should have been reasonably knowledgeable to fly a gyroplane.

 

Wrong, I was in more danger than a beautiful naked virgin at a Hells Angles beer bash.

 

The Gyroplane that I bought as a kit and built , unknown to me was terribly flawed in its design due to being a pusher prop with a thrust offset of around 10 inches above the vertical center of gravity as well as using the offset gimble head rotor system.

 

This design flaw will kill you faster than the mind can follow should the Rotor Thrust change due to turbulence , pilot induced occilations or a sudden unloading of the rotor at low airspeed at high power.

 

What you then get is a power pushover resulting in a foward bunt and the airframe overunning the rotor, cutting off the tail.

 

If anyone out there is interested in this rather interesting side of rotary aircraft aerodynamics I would be happy to discuss the information that I have over the years absorbed about these very interesting flying machines.

 

Also I hope to save a few lives by disseminating some facts about proper gyroplane design.

 

Are any of you aware of the number of fatal accidents caused by Power Push over in recreational gyros with high thrust lines?

 

 

By the way contrary to popular beliefe a properly designed gyro is a fantastic play toy with marvelous flight charestics ( how the f..k do you spell charestics??? )

 

 

Chas W. Doctor of Divinity.

[twinstar_ca]

ummmm..... that would be characteristics, rev c!!! :up:

[Charles W.]

Thanks Twinstar.....

 

I sometimes am quite challenged mentally and spelling wise.

 

Bless you my son.

 

Now I shall auto rotate off to bed.

 

Reverend C..