How to build A Safer RAF

[Jerseywing]

Well I just got my butt kicked and although I disagree with how things were said I can't and won't argue with the facts.
There is a boat load of info about Non CLT and the bad track record it has. My intent is to try to keep this thread going as long as possible to keep current/prospective and new owners informed on how to best get these craft to be the most stable and enjoyable craft they can be.
With that said I've seen a couple of owner modified RAFs where the keel was modified to lower the Prop thrustline. Their input would be an immeasurable help in getting it done right the first time instead of trial and error. (steel and aluminium are gettin pretty pricey these days and you can't burn the scrap in the fireplace!) To get things going I'd like to get some baseline data through the folllowing questions

1) How far above CL is the prop Thrustline? Does it vary by engine? If so How much?
2) What is the best way to lower it (besides an AAI kit)
3) I realize you can lower the engine and invert the reduction unit but is it better to
a)lower the engine alone
b) Lower the engine and invert the Redrive

4)I have seen references to several different H-stabs but only found one website for them. Where can they be found/purchased?

I guess thats enough for now, please reply with any ideas or experiences you have regarding the above.

Thanks,
Mike

[Aussie_Paul]

You just have to search. I started out as a fervent Raf supporter, BUT after I flew in a Raf with a stab and found it to be sooooooooo much better I was read the riot act by Don Lefleur about how I did not know anything about the situation. That coming from a guy who did not fly gyros. Don's excuse was a health problem. I told him to come down under where you don't need an aviation medical and learn to fly gyros so that he could talk from experience. The more I tried to help them the more they lied and eventually they "sacked" me as a rep, as they have done with any rep who questions their faulty knowledge.

Mike, use the search function to find all the posts that I have made in relation to Raf stability. Mike I am probably the most experienced Raf modifications guy in the world!!!!!!!!!

Why? Because I spent me money and was totally dissapointed. I put a stab on and that made it acceptable to me. The "real" experts, not he ones like Jim that have done heaps of hours but don't understand gyro aerodynamics, told me that I had only "bandaided" the problem. I asked why? and the explanations came thick and fast. It all started to make sense to this country bumpkin gyro pilot, so I built my next Raf using the advice from these good forum people and proved what they were saying. I called that the Hybrid as I started to put all this info into my own Firebird design. Hybrid used the Raf cabin and some parts, BUT I used the geometry that I intended to use for Firebird.

It is a shame that Norms info is lost, as I was posting almost daily about the results I was finding. I am sure that there are quite a few poster here who can remember me making a fool of myself, BUT not afraid to change my opinion when proven wrong. Yell out guys if you remember!! Maybe it was a figment of my imagination!!!!!!!!

Mike we have been through this so many times. As I said in an earlier post my thoughts about flying with Jim and Duane. I like them as a friend BUT am quite disgusted that they have no desire to improve themselves or their machines and have no desire to really help the gyroplane movement. As I said I enjoyed their company when we were on the same team, BUT they are wrong. Physics and aerodynamics prove it. No if buts or maybe's.

I am sorry that you have gotten upset Mike. As you said yourself you are a newbie, and like I was, you have a hellova lot to learn, and Jim is not the guy to give you the most important information.

No insults intended Mike.

I always tell people that it is just as easy to build a gyro correctly as not correctly. The hardest part is to know the difference.

I was involved with gyro gliders in 1961, but mostly with gyros since 1982 when I soloed a gyroplane. I have only learnt the important stuff since I put a h/stab on my Raf in 1999. BOY!!!! do I feel a fool, but I think that I am respected for my ability to change when proven incorrect.

I am only too happy to help people make a better Raf.

Regards, Aussie Paul.

[ventana7]

Mike,

Allan Wardell in Australia has a RAF with a lowered keel. He is a gyro instructor, 747 pilot, training officer for the Oz roto assn. and a SUPER guy. You might get onto the ASRA website and ask him for advice.

Rob

[GyroRon]

Not to be a smarty pants here, but the safest way to build a RAF is sold nationwide now by the name of Sparrowhawk.

[Harry_S.]

Hi Mike:

Being as your training in an RAF, why not come on the RAF owners/drivers thread and get some solid help/advice, from satisfied, experienced RAF pilots; who have hundreds of hours of safe and pleasurable flying, in their RAF.

We don't force it on anyone. We just like what we have and don't mind saying how much we enjoy flying it.

Cheers

[Aussie_Paul]

Hi Rob, Allan may have stepped the keel and lowered the engine redrive, but he put on a longer prop, so the gain was minimul. Allan is a good instructor and a helpfull guy, but his I am afraid that his Raf is very badly set up. The axle needs to be moved back 4" the 29' rotors are too small for the heavy Raf that he has with the ej-25 quad cam. and the prop is not matched the the power.

This is not knocking Allan at all, but Allan is reasonably new to gyroplanes and is still in the heavy learning curve. A 747 pilot means nothing in relation to gyroplanes, but I think that it helps Allan do a great job as Operations Manager for ASRA. He is a SUPER guy.

Aussie Paul.

[GyroRon]

Here is a serious question for Mayfield and Aussie Paul, Chuck Beaty and others...

How bad of a thrust offset would you have if you took a stock RAF - with Stab - and used a AAI redrive instead of the RAF redrive and then raised the engine however many inches up the mast the redrive swap would require?

[StanFoster]

Mike: I have a Parham stab on my RAF set at two degrees nosedown with the keel. I can assure you it handles nice in all kinds of wind....and the vertical winglets also make flying with the doors on a breeze. I have noticed nothing but very relaxing flights...and my plans are to continue enjoying flying my RAF year round and posting pictures of Illinois/Indiana. If only I had known last winter while finishing my RAF...how much I have enjoyed my 120 hours to date in it. Also....my "biggest" surprise about learning to fly my RAF..was that there wasnt any surprise...

Stan

[Aussie_Paul]

Remember Stan that you had quite a bit of HTLM experience, didn't you?

Aussie Paul.

[StanFoster]

Paul: I really dont have near the experience that many here have. I started with a 90 horse mac powered Bensen....trained myself and flew it with many engine outs and no damage. I then bought that Air Command that I also trained myself to fly..and it also had many engine outs until I switched engines. I then of course started flying my RAF this year...I "was" going to seek training and in fact was going to train with Ron Menzie. But as the archives show....I kept slowly getting used to it by taxiing....and then to crow hops...that I soon was flying it without training. I am not in the least condoning self training....I just am stating a fact that I was very comfortable with it. My biggest problem with learning to fly it was the surprise I had in how easy it handles. I am just a pilot with average skills....but I do fly very relaxed. I never proceeded to the next step until I my sure of what was happening and why.

Learning to fly my three gyros have been a very rewarding experience. My RAF so far had proved very dependable and I am looking to flying all winter in heat. I cant wait to post snow covered Illinois.

Stan

[GyroRon]

I was asked for a pilots report on some of the gyros I have flown at ROC. I have not had the time to sit down and write them yet, but will shortly comment on one machine I flew there.

I got a chance to fly a HTL aircommand with power via a EA-81 Subaru with belt redrive and warp drive prop. This thing was a low riding machine! All it had was the little aircommand tail and stab on the botttom of the rudder. I was nervous about flying it and it took several days before I finally got talked into flying the thing - I just didn't see the need to risk myself for the thrill of flying another machine, and this thing looked to be a powerful machine with a high thrust offset and a dinky little tail on it. The current owner - who has had the machine and flown it for the last 10 plus years is sorta scared to fly it himself.

Anyway I got in the thing and flew it around ROC for about 30 minutes. Long story short, it flew darn good. It didn't do anything weird, it was perfectly controllable, and it felt for the most part stable. Remember I just used the word FELT

Now that I flew it I can see where some of the HTL pilots feel they don't need a gyro on long legs. I can now see why people like Stan feel "Comfortable" in their machines.

I suppose that if flown carefully and no hotdogging was done, flying a machine like that Aircommand would be just fine. BUT.....

If any of the HTL drivers, that are used to flying only machines that flew like that Aircommand, Well if these pilots could get a hour or two of time in a machine like a Dominator or other CLT type machine they would be able to feel the difference. Especially if they tossed the gyro around and did some hotdogging.

I know some people may feel that a HTL gyro or a unstable gyro would be all over the place, that it would bob up and down in pitch, that it would just be a handful to fly. My experience with this machine shows that it did none of that. Matter of fact, it was very Stable feeling. Felt like I could have flown the thing hands and feet off or stick locked, it just flew without any fuss. Pitching it over in hard turns, or zipping along at higher speeds, or generally hotdogging the thing showed where it wasn't as stable as a gyro such as a Dominator.

But what the pilots of these machines have to come to grips with is even though it feels so stable and easy to fly, the gyro can still easily bunt over and kill you if you get the rotor unloaded and the power setting is not reduced fast enough. This is enough reason for me to want to make sure my machine is CLT and that this deadly trait is not possible in my machine.

The point to this post is that now that I have flown a machine simular to what Stan has been flying, I have seen where it flys pretty nicely. I now understand why these guys think all is well with their machines. but I also want to express that a experienced pilot can easily feel a positive difference in a CLT gyro. The stable feel you have, is a more solid stable feel with CLT.

[Doug Riley]

Ron, the offset gimbal head can make almost any gyro -- no matter how badly the frame is laid out -- fly pretty nicely as long as the G's don't vary too much. The first form of G-instability you're likely to run into is a need to add forward stick pressure in a steep turn. That's a backwards reaction, as you well know. It's a really obvious sign that the rotor thrust line is ahead of the CG: increase the rotor thrust in the turn, the rotor thrust pulls UP on the nose and you tend to slow down unless you respond with FORWARD stick.

When I took a check ride for my BFI a few years ago, I rode with Ed Alderfer in his no-HS SXS lowrider Air Command. I used to fly a no-HS A.C., but hadn't flown such a machine in a few years. There were a few confused minutes when I started doing turns and the machine would slow down, until the light went on in my feeble brain. It was an "Oh, yeah, THAT" moment. I had forgotten the forward-stick bit.

The gimbal head can't stop a PPO, because it uses rotor thrust to impart stability to the gyro. Zero G equals no thrust, and that puts the head out of business.

[GyroRon]

Well that is kinda what I experienced. Straight and level just flying along it was very stable feeling, Easily could be described as " Comfortable."

Trying to whip the gyro around in a turn, or making a high speed pass or other various flight modes, the gyro had a less than stable feel to it.

Of course it is worth mentioning that it was early in the day when I flew it and winds and thermal activity was very low.

There was a few people there at ROC that wanted to possibly buy this gyro. I and others were trying to express the importance of adding the CLT kit to this gyro if they bought it. The counter arguement they used was they weren't looking for a hot rod, or high performance machine... They only wanted to fly straight and level and see the sights. They assumed after watching me fly my Dominator like a wild man, and watching the Aircommand - with me or the owner flying it - more easily, that the only reason for the CTL was to be able to do hotdog flying.

When people get over the looks factor, and the mindset that it is more important to have the gyro low to the ground for ease of getting in and storage and ground handling, Then they might start to see the reason CLT tall machines are the only way to go.

I can understand how some here want to defend their make and model gyroplane. Who wants to admit that they are flying a flawed or less than perfect machine? No one I know. But if you use a open mind and think about the dynamics and better yet just try the other configerations, they would see what their machine lacks.

I will say that flying that aircommand was a eye opener for me. Up till that point my gyro flight experience has been limited to near or below CLT gyros only. It wasn't a bad flying machine.

CLT does not make a gyro a hotrod or performance machine. If you see Dominator and Monarch and CLT aircommand pilots doing what appears to be radical flying, the part of that flying where CLT is a factor is that the CTL takes away alot of the danger factor that flying a HTL gyro in the same manner would have. All gyros can be tossed and turned and flown in a manner that could be easily described as hot rod flying. The difference is the pilot flying the CLT machine is not flying on the edge where as the HTL pilot can be.

[LARRYEBOYER]

I believe a newbie should stick to a CLT machine. There is less likely hood of getting into a situation they don't have the experience to react to fast enough.On the other hand, a RAF is an excellent machine for somone with some skills as long as ir has a H.S. I have the Larry Martin "Ultamate Stab" and it is a joy to fly. I use to get oscilations in pitch with his other stab in gusty conditions.(also nervous). The new stab has removed all of that and it flys great. I had a CLT aircommand. It was my first gyro and it flew solid and controllable. I don't feel any difference with my RAF. I am almost done building my New RAF with a stepped keel. I am looking forward to reporting on it's handling characteristics.Aussie Paul flew a similiar gyro like my new configuration and he said it was the best RAF he ever flew.So I don't think the only safe handling RAF is a Sparrow Hawk. There are hundreds of happy RAF pilots that have added stabs or stabalators or dropped keels or just left it in the original configuration that happily fly.It is a matter of skill and choice. Get the training in type you hope to fly, then you decide. This forum is full of good advice and helpful input.Good luck.

[StanFoster]

I would like to add that when I load up my RAF with more g-s...there is definately a need for more back stick pressure and quite a bit of it. It would spook the heck out of me if I had to push the stick forward.

That was one of Gregg Gremmingers stability tests I took in my RAF and it did everything it was suppose to.

Stan