A few years ago, at the 3I farm show, I saw a homebuilt helicopter on display, that was powered by a Chevy small block through a belt drive system. The amazing thing about this helicopter was the rigid rotor, which the builder had designed himself, and which gave it some amazing performance numbers. It appeared to have a carbon fiber sheet that was laid along the chord of the rotor blades, with some kind of high density compressible composite bonded to both the top and bottom of the carbon fiber to form the airfoil. I tried to find information about it, but can't find anything on the internet. the only other thing that I can remember is that it was made somewhere in either central or western Nebraska. Recently, the plan for one of my experimental projects evolved, and a rotor like that would sure come in handy. If any of you have some more information, or contact info, I would greatly appreciate you sharing it.

Quis

The 3I farm show has been in Kansas instead of Nebraska as far as I know, if that helps with your search.

8000 wrote:The 3I farm show has been in Kansas instead of Nebraska as far as I know, if that helps with your search.

Yes, sorry if I wasn't clear. When I saw it, I was at the 3I show in Garden City, but the guy who was showing it said that it was made, and had been flown down from Nebraska.

Jerry Behnke in Cambridge, NE was mechanic of the year in 56 or so and the FAA gave him a helicopter course. He might know something about it. I sprayed for him in the three best Pawnees I ever flew.

Thanks Contact. It was the Pawnee Helicopter Co. I happened upon a picture, finally, which led to a name, and now I just have to find who bought the molds and designs, when the company went bankrupt. I might still have to give Jerry a call, so I can get the complete local story, since it sounds like the helicopters were built just down the road in McCook. It is a sad fact, but I think homebuilders could get some really good deals on parts and tools, if they would just pay attention to what small aircraft companies are having bankruptcy sales.

You know, if I had just posted this question a few years ago, I probably would have found it on my own much sooner. Funny how things work like that.

A ridged rotor can't seek or flap. Those stability functions have to be provided with electronics. That is the main reason that the Army wouldn't buy the Cheyenne.

Rigid rotor helicopter.. The BO 105 has a titanium rigid head milled out of a single block.

contactflying wrote:A ridged rotor can't seek or flap. Those stability functions have to be provided with electronics. That is the main reason that the Army wouldn't buy the Cheyenne.

As I recal, the rigid rotor system that I was looking for (on the Pawnee Chief) had no electronic control, but each blade was controlled directly, with no dampers or other mechanisms. Flaping and seeking were accomplished through blade flex. Supposedly, this gives more stability, efficiency, longevity, and less vibration.

Quis wrote:

contactflying wrote:A ridged rotor can't seek or flap. Those stability functions have to be provided with electronics. That is the main reason that the Army wouldn't buy the Cheyenne.

As I recal, the rigid rotor system that I was looking for (on the Pawnee Chief) had no electronic control, but each blade was controlled directly, with no dampers or other mechanisms. Flaping and seeking were accomplished through blade flex. Supposedly, this gives more stability, efficiency, longevity, and less vibration.

This.

Lead, lag, and flap are all done by the rotors themselves flexing. Benefits are fewer moving parts, smoother rotor system, faster control response, and a wider CG range.

Sounds good. If it's simple the Army should like it. Too bad the government is bankrupt.

contactflying wrote:Sounds good. If it's simple the Army should like it. Too bad the government is bankrupt.

True, but they're expensive and from what I understand up until the past few decades the materials weren't there for long-term reliability.

contactflying wrote:Sounds good. If it's simple the Army should like it. Too bad the government is bankrupt.

Yes, Cam Tom is right. The old rigid rotor systems that the Army tried in the past, are a lot different from the new ones today. I would have thought that some of the older advanced materials, like Kevlar would have worked, but evidently not.

Waterboy wrote:Rigid rotor helicopter.. The BO 105 has a titanium rigid head milled out of a single block.

This is Chuck Arron flying MB105 over southern California . Red Bull is owner /sponsor that does all the airshows . I flew with Chuck on maintance test flight ~ we may have gone inverted .

182 STOL driver wrote:

Waterboy wrote:Rigid rotor helicopter.. The BO 105 has a titanium rigid head milled out of a single block.

This is Chuck Arron flying MB105 over southern California . Red Bull is owner /sponsor that does all the airshows . I flew with Chuck on maintance test flight ~ we may have gone inverted .

I've heard he keeps ballast in the nose for a very fwd CG to allow the loops. Any truth to the rumours?

A Warrant Officer in Alpha Troop 1/9th Air Cav looped a Cobra in Vietnam. We called him Captain America because of his helmet painted with the American flag. You may have seen a stunt pilot playing Captain America, Mister Graham, in "Apocalypse Now" except he was flying a loach.

http://www.chonday.com/Videos/helifliplix2

Cam Tom 12,

What is going on with this one? Is the homebuild just staying positive or is it true ridgid rotor. The Army one is ridgid and it goes negative...lots.

contact

ps. rename the thread to update.

Actually, it looks like there's coning on the disc in that whole video. Negative G isn't a great idea even with a rigid rotor because as G goes down you'll lose control effectiveness and can even get into control reversal.

As far as what's going on with the homebuilt - beats me! I'd love to talk to the builder though!

Did you see the Army Lynx video? He went negative in the push over.

Hey guys, sorry that I haven't replied lately, but I haven't been online much. I found that the helicopter blades from the experimental that I was looking for are completely rigid. After the company that created them went bankrupt and was liquidated on Big Iron (a bunch of farmers who were only looking for tools and scrap bought it all initially) one of the project engineers eventually ended up collecting all the parts and is hoping to start the original project up again, but he has run out of funds. I contacted him about the heads and blades, and he said that he would show me how they were made and maybe help me out. He also said that while the helicopters with those blades showed very good performance in cruise, they could 't hover out of high ground effect. I wonder if this is because the blades that they were using were rather short for the weight of the craft. I was going to fly up to McCook and look at them, but I didn't have the greatest year, due to high farm input prices, low crop prices, and lots of hail, and I couldn't afford to do anything with them right now.