PRA September 2005 Article

Rotor-Head

Shawn Adams
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Jacksonville, OR
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Air Command Elite 503 DCDI Sport Rotors - Cesnna 152-172 - R44 - MD500D/E - QuickSilver MXLII Sport
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220 Fixed Wing - 3000+ gyro 600+ Helicopter
On page 32 and 33 of the September 2005 PRA magazine, I saw a familiar story about Townson. I am sad to hear about his passing.

The helicopter pioneer story I am working on ( https://www.stewartrgraham.com ) is about a guy who knew Townson and got a few pictures of his machine that is in the PRA article... Her is one of the pictures I have from him (front and back of the actual film I scanned).

Stew had a great story he told me about that aircraft and pilot... I have it on video and I may try to post it if I have some time....
 

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How does that thing deal with retreating blade stall? Looks like it would want to flip over with those ridgid fat blades??
 
barnstorm2 said:
How does that thing deal with retreating blade stall? Looks like it would want to flip over with those ridgid fat blades??
I'm not sure. Stew told me that the blades were symetrical and partially powered (but I have never even heard of the machine until Stew told me, so I know nothing about it...) I'll try to locate the video I shot of my conversation... I think he said he actually saw it fly in 1937.
 
Okay.. I found some video. It's pretty crude since I just set the camera up in his livingroom and let it roll. I lowered the quality to save downoadtime, but the audio is most important anyway...

That's me sitting next to Stew and then it's me going throught his archives to find the Herrick converter plane photo...

https://www.rotor-head.com/herrick/
 
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Shawn
a Brit publication of "The Aeroplane" Feb 1991 had a feature on what it described as Mr Herrick's Convertiplane. As there are some 4 pages of text and photos what it is you need? Included are spec, 3 view, summary by test pilot Townson, 8 photosand general discussion. Happy to pass on what you want. Dont be shy now
 

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Ga6riel said:
Shawn
a Brit publication of "The Aeroplane" Feb 1991 had a feature on what it described as Mr Herrick's Convertiplane. As there are some 4 pages of text and photos what it is you need? Included are spec, 3 view, summary by test pilot Townson, 8 photosand general discussion. Happy to pass on what you want. Dont be shy now
That's cool. I actually don't need anything.. I just saw the article and had the picture and I was just passing it on to whoever else was interested in information on this aircraft.... thnaks.
 
September issue?

September issue?

There was a September issue? The last one I got was from August and I got it in November. Haven't received it or the Oct-November one...
 
Herrick

Herrick

I have seen the machine in person and have some photos of it. The rotor is a see-saw type, not powered at all. In airplane mode it has the blades restrained and they act as an upper fixed-wing. The blade is
wound backwards against internal bungees in the rotor blade and then latched. When they are released, inflight, the bungees prespin the blades and they are allowed to "flap" on the teetering hinge, partially restrained by rubber bisquits to prevent "overflapping".

George did over 100 inflight conversions in it!
 
RHerron said:
I have seen the machine in person and have some photos of it. The rotor is a see-saw type, not powered at all. In airplane mode it has the blades restrained and they act as an upper fixed-wing. The blade is
wound backwards against internal bungees in the rotor blade and then latched. When they are released, inflight, the bungees prespin the blades and they are allowed to "flap" on the teetering hinge, partially restrained by rubber bisquits to prevent "overflapping".

George did over 100 inflight conversions in it!
That's very cool... It's a neat aircraft.....
 
for additional entertainment, take a look at the rotor profiles
this machine was able to fly as both an autogyro and a biplane
to do this the rotor doubled as the upper wing
its most interesting that the profile section of the rotor is ogival in form, that is, it is an arc not the usual thing. This allows the section to gain lift in BOTH directions! where it a normal rotor the opposing side would be facing backwards, whereas in this case the profiles are the same both forwards and backwards.

More on this, if you diagramaticly draw the line of zero lift (that angle where the section produces no lift)

~ and this is done by dividing the base of the section down its centre, then halving the perpendicular between base and top. Next draw a line from the trailing edge through that point, the angle described is that of zero lift~

Thus although the base of the rotor section be flat, the angle of zero lift is always positive and symetrical. Sorta neat huh
And ponder this, if Herrick had allowed the 'top wing' to swing in flight, he would have demonstrated swept swing wings way before any other practical examples, F111 be dammed :)
 
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