Subject: Autogyro
From: rotaryeng
Date: 2/17/2014, 10:53 AM
To: AAA-rotaryeng


Paul,

Do you have details on autogiro's running rotaries ? Pardon my thoughts, but I think a rotary would work well.


Thanks,

Barron

I don't have any dwgs but Gary Buster might help you out.

http://www.youtube.com/watch?v=QOwb8QRHrMY

Paul Lamar



Back in the days of the late Cierva and before the Advent of the helicopter the autogyro was quite a capable machine. It had heavy two or more bladed rotor systems which stored a great amount of energy. Todays autogyros on the other hand in my opinion as a rated Chpl with IFR must be the daftest thing out there. Flimsy contraptions with energyretention on the scale of a chopstick. You would not find my behind in One of them on a calm, stable day let alone in any kind of turbulence. Surprises me they are legal.

Lutz Strobel

Have you looked at the you tube video?
http://www.youtube.com/watch?v=QOwb8QRHrMY

I filmed the video. Looked pretty good to me. However it was a calm day.

IMHO the main problem is MPG.

Paul Lamar

Actually the main problem is negative G's When that happens the disk is no longer loaded and looses momentum, which is where the lack of stored energy due to the low mass of the rotor system comes in....
the second severe problem is the underslung rotorsystem most of the nowadays ( refuse to callem modern ) autogyros employ. It can kill You fast. In summary stay away from them, even if a crash of one of them would have nothing to do with being powered by a Rotary engine, it would still rub off. - Lutz Strobel


We are not doing outside loops here :)

There are a lot of them in the States. If the accident rate were much higher than other experimental aircraft the FAA would be all over their case.

Paul Lamar


A lot of people think a gyro works by weight shift, it does not, the teetering rotor and gimbal head allow the rotor to in effect change pitch around the circle as the advancing blade would have more lift than the retreating blade if it did not teeter They are not as simple as they look.

John Evans



Lutz you should try them although I think no one could pursuance you to do so now. They are fun and safe, and handle turbulence very well. If fact you do not feel any at all even in very high wind. The "rigidity" which is the percent of lifting surface in the whole disc is very small, compared with that of a plane which is 100%, so turbulence is no issue for a gyro.

Gordon Gao

Thanks for the warning Lutz, but I think if flown properly the gyro's are as safe as the next aircraft. Many people see the "open cockpit"
and can't imagine flying them. This is because people don’t understand them, and this is understandable as they are not as common as their fixed wind counter parts.


Thanks,

Barron

Its not about outside loops or any such stuff. Remember the FAA put a restriction on R22 Helicopters regarding flight in turbulence ? They experienced mast bumping ( bet most auto gyro pilots today don't even know what that is ) and in some instances even cut of their own tail booms ! Anyone who has ever flown in the mountains with strong winds, or in the vicinity of thunderstorms ( you'd be surprised how far away their might extends ) knows that negative G's are NOT a question of a barrel roll gone wrong..... If you think that negative G's are something you induce yourself please see your local CFI again ! Better still attend some real helicopter ground instruction.

Fact is: once that rotor disc is not driven anymore by airflow from below it starts to slow down and when that rotation becomes slow enough your contraption becomes a not so streamlined anvil. And no, i don't have anything against light aviation. I am an active glider pilot and have even participated in the German national championship in hang gliding back in 1992.

Lutz Strobel

There are 100's flying in the states and I'll bet the accident rate is no higher than hang gliding. People don't fly them in thunderstorms and they don't use them for getting from one place to another. Strictly recreational.

You would not fly your hang glider in a thunderstorm would you?

Just put a tach on the rotor disc and an alarm :)

How people choose to kill them selves is nobodies biz but their own.
When is the last time a gyro crashed and killed some one on the ground?

Government, get  out of my life and I don't want to pay them to do it.

Paul Lamar


    I'd say an autogyro is a rotating wing, that instead of obtaining lift
    from the airspeed of airplane's wings, it obtains lift from the airspeed
    of blades rotating against the air, in fact, autogyro and helicopter blades
    are very high aspect ratio wings, the ones with a better lift to drag ratio,
    the trick in autogyro is that once a certain speed of rotation in terms of
   rotor rpm is reached, the turning of rotor is self-sustained by the forward
    airspeed of flying machine, no need to apply power on the rotor shaft, although
   some models had a clutch that temporarily connected the rotor to the
   engine, in oder to make a 'fast jump' takeoff, for example, going over
  obstacles in the flight line.
   Thanks for your attention. Best regards.
     Salut †

                    Jose Gros-Aymerich
                    Madrid, Spain


Sure, I know what mast bumping is and I have seen several videos, however from what I understand autogyros do not experience this the same way a helicopter does.    That is because there no powered mast to provide the torque as there is in a helicopter.  The rotor if a gyro spins on bearings.   However gyros can still have an issue with Negative G's thus losing altitude and the loss of rudder authority means that the gyro can rotate itself right into the rotor, usually chopping the tail off

Ref: Try_Cyclic


Thanks,

Barron

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