What will change for YOU if the medical changes go through?

Here's the place to ask all of your medical questions. But don't believe everything you read!

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RotorRambler
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Re: What will change for YOU if the medical changes go throu

Post by RotorRambler »

drseti wrote:Welcome to the forum, Ira - it's nice to see you posting here. As it happens, I bought your book a few months back, and have enjoyed it immensely. Although I am not gyroplane rated (and actually have yet to fly one), I've been friends with Ralph Taggart (father of the Gyrobee) for about 40 years, and he's always encouraging me to try them out.
Thanks for the welcome. I'm mostly a lurker here rather than a a poster, and I've enjoyed reading your comments.

I hope you get a chance soon to see how a gyroplane would suit you.

Ira
Ira McComic
http://www.Light-SportGyroplanes.com
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Merlinspop
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Re: What will change for YOU if the medical changes go throu

Post by Merlinspop »

Ira,

Is it just my (mis)perception, or does the rotor disc of a gyroplane contort much more than that of a helicopter in the various flight regimes? Particularly at takeoff, it sure seems like that disc is bending up into the shape of a warped salad bowl. It always reminds me of someones baseball cap being blown off in a direct headwind.

Oh, and welcome!!
- Bruce
RotorRambler
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Joined: Wed May 14, 2014 9:30 am
Location: Plano, Texas
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Re: What will change for YOU if the medical changes go throu

Post by RotorRambler »

Merlinspop wrote:Ira,

Is it just my (mis)perception, or does the rotor disc of a gyroplane contort much more than that of a helicopter in the various flight regimes? Particularly at takeoff, it sure seems like that disc is bending up into the shape of a warped salad bowl. It always reminds me of someones baseball cap being blown off in a direct headwind.

Oh, and welcome!!
Thanks for the welcome.

I assume the gyroplanes you've observed at takeoff were the smaller, lighter gyroplanes that qualify as light-sport and which have a two-blade teetering rotor. A helicopter's rotor system can be more complex, but it can have a two-blade teetering rotor. When comparing the coning angle on takeoff between a gyroplane and a helicopter, both with a similar kind of rotor system, I think the physics support your observation.

The coning angle of a rotor disk is mostly a function of the weight the rotor is supporting and the angular momentum of the spinning blades. The more weight the rotor has to suppot and/or the slower the rotor spins, the greater the coning angle.

Most takeoffs in helicopters are made from a hover and you'll probably see some coning as the aircraft is brought to a hover and it begins supporting the aircraft's weight, but the amount of coning doesn't change that much as the helicopter takes off; that is, transitions into forward flight. In fact, as the helicopter achieves translational lift, the more efficient airflow across the rotor may allow a lesser coning angle.

On the other hand, a gyroplane typically makes a running takeoff, similar to an airplane, and the rotor isn't supporting the full weight of the aircraft until the wheels leave the ground, and at that moment, more coning occurs. And at that time, the rotor on the mast may look a little like an umbrella on its handle, the cover turned up by a strong wind, but not that extreme.

In other flight regimes, I don't think you'll see that much of a difference in coning angles.

In the future, please go easier on me; I almost wore a hole in my brain having to think about all that. :D
Ira McComic
http://www.Light-SportGyroplanes.com
Interested in gyroplanes?
Click below to learn more about this book at Amazon.
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Merlinspop
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Re: What will change for YOU if the medical changes go throu

Post by Merlinspop »

RotorRambler wrote:In the future, please go easier on me; I almost wore a hole in my brain having to think about all that. :D
Oops! Didn't mean to exceed the RPM limitation on your cranial mouse wheel (I hate it when that happens to me). Sorry about that!

I've always been fascinated by gyros in the same way that I am with magicians. Still trying to figure out the trick, because they can't possibly be real! :wink:
- Bruce
Merlinspop
Posts: 999
Joined: Mon Apr 08, 2013 2:48 pm
Location: WV Eastern Panhandle

Re: What will change for YOU if the medical changes go throu

Post by Merlinspop »

Ira, in the time since you wrote your explanation, I've done a bit more reading and I never fully understood the absolute necessity for air to flow UP through the rotor blades, or else "bad things" happen. I still don't fully understand it all, but now your explanation and the shape of the 'bowl' makes a whole lot more sense now.
- Bruce
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