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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