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, :D 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. :eek: 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!!!!!!!! :eek:

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... :D

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. :D 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. :eek:

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

Stan

[Aussie_Paul]

...........as I was going to say that for you to say the things that you have, and I agree with them, the air would have had to be smooth. As Doug said re the varying G loading. This varying of G loading is happening all the time in rough air and the rougher the air the greater the changes in the G loading.

With experience, Stan and others including myself will adapt the stick and or power to control the excursion that will take place if allowed to. An experienced pilot in these HTLMs "fix" the problem before it even starts. They just know by the "feel" of the gyro what it is going to do. I call it "nipping it in the bud" before it gets severe.

You cannot apply that logic to a newbie just qualified to start learning to fly for the rest of their life. That is all a licence is, a ticket to really start learning after they have been taught the accurate basics.

That is why most of my posts reflect that "I always look at any gyro thru the eyes of a 15 hours of gyro dual student. Is this machine going to help or hinder thios student to become a successful gyro pilot?"

Aussie Paul. :)

[Aussie_Paul]

....the stick fixed testing if you want a hellova fright!!!!!!!!
Your machine could not go close to meeting stick free let alone the stick fixed tests of the Sport Pilot stability standards. Of course you don't have to meet those standards to have a comfortable gyro to fly as GyroRon said.

I have conducted all those tests in a Raf with an effective stab, and had to be extremelly carefull :eek: after conducting the same tests in Hybrid. I don't need adrenalin rushes these days, do you Jim mayfield? :D

Aussie Paul. :)

[Mayfield]

Reading Paul's message traffic brings back memories of some of the absolute guff I actually taught at one time in the late 80s and early 90s. I should have known better then and ultimately learned enough to give fairly decent instruction:

1. Anticipatory control inputs: What a name. I guess I wanted to explain what the student needed to do. I reached the point that I could tell a student "Ok now, the nose is going to start to come up now! Just a little bit of forward pressure. Don't really push the stick forward, just keep it from moving back. Do you feel it? Now since the stick was pushing back against your hand now it will start pulling. There, catch it. Just enough back pressure to keep the nose from going down."

2. Pull/Jab: "Ok, the nose is dropping now! back pressure! No! not that much! There you go! You caught it! Whats it going to do now? Thats right; the nose will try to come up. Give it just a little jab. Take out what you just put in! come on, just a little jab. That's it, you've got the rythym now!"

Lord I'm ashamed of those days! I really thought that was how a gyro had to be flown!

Live and learn I guess! The trouble is that you only learn if you live.

R/S and still trying to live down my ignorance.

Jim Mayfield

[StanFoster]

I catch myself just cruising around a lot in my RAF with my hands off the cyclic. I remember doing those anticipatory inputs Jim was talking about while flying my Bensen...but for the life of me can not recall ever doing those little inputs in my RAF.

I remember talking to Jeff Milburg last year and he was telling me that he flew most of the 60 mile flight to the Shelbyville fly-in in his RAF with his hands off the controls. I had my HTL Air Command then and I commented that it flew nice but I could never let go of the controls for very long.

The RAF is the easiest thing I have flown yet....it just feels like its part of me. I can only imagine how it will be after 500 hours. :)

Stan

[banaari]

"Ok now, the nose is going to start to come up now! Just a little bit of forward pressure. Don't really push the stick forward, just keep it from moving back. Do you feel it? Now since the stick was pushing back against your hand now it will start pulling. There, catch it. Just enough back pressure to keep the nose from going down."

2. Pull/Jab: "Ok, the nose is dropping now! back pressure! No! not that much! There you go! You caught it! Whats it going to do now? Thats right; the nose will try to come up. Give it just a little jab. Take out what you just put in! come on, just a little jab. That's it, you've got the rythym now!"

That was exactly my Intro flight in a nutshell about 7 years ago, in what I believe (looking at the photos) was an un-stabilised RAF. Right up until reading this forum (in the last month) I believed gyros were fundamentally unstable...

John

[Chuck_Ellsworth]

Banaari :

Stock RAF's "are" fundamentally unstable. :D

[KenSandyEggo]

That's exactly how my first 2 hours with Jim also went. That's how you had to fly an unstable RAF. The pitch excursions were extreme until your brain learned how to compensate some. That's something new students don't have to do anymore in a stable gyro, or even in an RAF with at least a stab. When I came out with my stab, Jim was my first customer.

[bones]

First off get yourself a good quaility camera, take a close up shots of it after getting the photos developed take it to the tallest building in your city and throw the picture off the top. :eek: :) :D
This is just in jest guys :D

[birdy]

Stan said,

"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."

Stan ,mate,don't let your machine lull you into a false sence of comfort,ANY machine will get into trouble if it hits extream shear,[and this can happen anywere] and is not controled.

Ron,I appreciate your honesty and truthful post on the HTL machine.

On several occasions I'v read where people have experianced a backstick pressure while turning.Could someone explane this,coz neither of my HTL machines do it and it's ment to indicate instability.

I'v never experianced what Jim explained in either machine,I just let the stick float and it just cruises right along.

[StanFoster]

Birdy: Thanks for your polite warning.....I do appreciate it...and I do fly aware of the fact that should I encounter severe turulence...CLT would be much friendlier... :)

What turbulence I have encountered to date hasnt required anything significant on my part...except finding my left hand lightly on the throttle. I do fly relaxed but aware of what my HTL could do in a hurry if I hit something nasty. I dont go chasing the stick but just kind of let it float. I never have seen anything that caused any concern ....but I am not flying in denial that I wont come across some severe unforseen turbulence.

I really think the guys that have gotten in trouble have done so because they are all tensed up and start fighting it. I know that CLT would be a big asset if you are tense and it has to help even relaxed pilots.

I dont mind flying in high winds....but what I am extremely cautious about is flying around thunderstorms. Years ago I was in my Quicksilver about 3 miles southwest of the airport when I noticed a roll cloud about 10 miles to the northwest. I immediately headed for the airport and it was soon to be realized that it was a race to the hanger. The closer I came to the airport..the slower my ground speed and the buffeting was awful. I almost turned 180 but stuck it out and just got my ultralight inside the hanger doors when that turbulent gust front went through. To this day I am a "chicken" when it comes to flying around on stormy days...doesnt matter what...either the Cherokee 180 I flew or my gyro.....both stay in the hanger. :D

I do fly conservatively and am enjoying my flying experiences far more than expected. I plan on continuing flying safe and relaxed and never tiring of the Illinois/Indiana terrain. :)

Stan

[mceagle]

I did most of my instructing in a low C of G machine and I never experienced the Gyro reaction that Jim describes in #18. Just about all the students PIOed initially but soon got over it within usually the first hour. When the student started to PIO all you had to do was stop the student moving the stick and the PIO stopped immediately. The gyro did not tend to PIO by itself. Perhaps the small stab. we ran in those days did have some effect.

[Mayfield]

During this same period I also used a big tandem, like a Parsons. Although it had a very high thrust line it also was pretty easy to fly. The student would PIO at first, but the period was so long that within a couple of hours they got over it.

In the shorter coupled cabin machine (my RAF without stab) the transition was harder. I suspect it has to do with the period of the oscillation.

Jim

[Aussie_Paul]

Tim, I think maybe the big grunt horsepower that is availible today makes the difference to what we felt back then.

Hybrid takes off at 5300 engine rpm and cruises at around the 4300 to 4700 depending on weight. That is a big amount of reserve power. I have 130 hp compared to the 65 hp we used to operate back then, and the gross is not double!!!

Aussie Paul.:)

[Doug Riley]

Birdy, whether you get the reverse stick pressure reaction when you bank a HTL machine will depend on a couple things.

The gimbal head does try to produce the correct stick forces, through the action of the offset. The offset uses the increasing rotor thrust during high-G maneuvers to produce a stick-forward pressure... as long as the rotor thrust line stays BEHIND the rotor head's pitch pivot. Normal flapping ("blowback") brings the rotor thrust line closer to this pivot than the full offset distance would indicate, however How much closer depends on the rotor design and on airspeed.

If the head has more offset than it needs to take care of flapping AND if the trim spring is a long one (i.e. it doesn't kick in a lot of extra back-pull as the nose comes up), then the head may succeed in overcoming the reverse-force problem. A short, stiff trim spring would tend to make the problem worse, as would a rotor with a high flapping ("blowback") angle or a very tall rotor head. Both of these latter things "use up" gimbal head offset in the course of compensating for flapping, so there's less "leftover" offset to help create the appropriate stick pressures.

A HS with enough incidence to counter the PPO moment will fix the problem completely, as will CLT.

[StanFoster]

Doug: Your posts are always so interesting to read. I am wondering if my stab being set at two degees nose down with the keel..which itself is also flying two degrees nosedown.....that this 4 degrees of negative pitch my stab has is why I never notice all the quirks that I read about. Like I said...I thoroughly did Gregg Gremmingers stability tests....and Jim Mayfield even e-mailed me with some to try. I can honestly say it is reacting the way its supposed to.

All I know...and I know some are probably tiring of this...is that it just feels right...and I am never fighting it. I have been in all kinds of wind....and fly in lots of thermals...and at the worst have kept my hand on the throttle.

I dont know if you recall...but early this year I checked the angle of my keel in flight by using a warp drive bubble level indexed to the my dash. My dash is 19 degrees forward when the keel is dead level. So...any reading higher than 19 degrees is what my keel is flying at nosedown. My bubble level reads 21 degrees at 55..65...75..and even at 85. This shows that my keel runs two degrees nosedown..and also doesnt change at those airpspeeds.

I am not going to touch it as it feels right. It may be a little draggy...but I am flying for comfort and not for speed.

Doug..keep up you enlightening posts..... :)

Stan

[Doug Riley]

Stan: Just to chuck some rough numbers around...

If your HS is a symmetrical airfoil and it really is flying at 4 degrees of negative AOA, then it has a lift coefficient (C.L.) of around -0.4. This translates into about 3.7 lb. of down-lift per square foot at 60 mph.

If your HS is 10 sq. ft. in area, and if it doesn't catch any prop wash, it'll be making 37 lb. of down-lift at 60 mph. If the lever arm of the HS is 7 feet, then it's giving you 259 ft.-lb. of nose-up moment.

If your RAF has a thrust offset of a foot and thrust at WOT of 600 lb., then the HS can't hope to overcome all of the PPO moment at 60 mph with the throttle hammered. At cruise thrust, though, it might come reasonably close (given those area and lever arm dimensions that I just guessed at!). Certainly, every bit helps. As you go faster, the HS develops quite a bit more power -- since lift varies as the square of airspeed. The winglets may help increase the lift, and perhaps your tail arm is even longer than 7 ft.

If the same 10 sq. ft., 4-degree HS were inside the propwash, you probably could get full compensation for the HTL situation, though at quite a cost in drag and load on the tail tube. The propwash of most gyros will be 100 mph or more.

[birdy]

Geez Doug,if a machine was giving the negative feedback through the stick like you say,it's a very badly setup machine.

[Doug Riley]

Birdy: The machine I flew that had this reverse stick pressure effect was one of the MORE stable of the first generation of Air Commands (the low riders) . They all had an inverted Rotax with gearbox up, no HS and a 60" prop with 68" mast. The CG was about 5" below the thrustline on mine. At least I had the smallest engine, no pod, no extra tanks below the seat and no second seat.

I can't imagine what the machines with big engines and all that extra mass down low must have flown like with no HS. Maybe Tom Milton can comment. No wonder there was a spate of crashes in England.

[birdy]

When my RAF was stock it would have been worse than your AC Doug but it never did that.

[Cobra Doc]

OK folks, you done gone and done it. After reading just about every thread and post on the forum, intentionally or otherwise you've convinced me that with failing blade bars, exploding fuel tanks, gasoline corroded fuel system parts, trim springs that fall off, whale-tails that look pretty but don't do much else, and a tendency to suddenly fly inverted, there is no way to make a safe RAF. There are a couple of other details that I've notice in pictures that I want to actually eyeball before I decide if they are defects in design. For a rotor-wrencher, that has as much time sleeping in a flying UH-1 as I do, to say that any rotorcraft is unsafe really goes against my grain. My list of rotorcraft that I will stay away from completely is now up to 3. The Mini 500 tops the list. My job is placing big bets on pilots and aircraft. With everything I've seen here and read on the NTSB reports, the RAF isn't a bet I wish to place.

[Doug Riley]

Cobra Doc, there's simply no comparison between amateur designs and professional ones such as the UH-1. Almost all of the homebuilt gyros on the market have been "designed" by people who are geniuses with a wrench, welder or paint gun, but who know absolutely not the first thing about basic high school physics, much less engineering design or aerodynamics. (There's no reason why they SHOULD happen to know this material, unless they've worked in the industry, taken night school or studied up on their own.)

When shopping among the homebuilt gyro designs, the burden is on the shopper (you 'n' me) to inquire what kind of formal engineering review a design has received. Chances are it's ZERO, but there is the occasional exception. If the seller claims to have "engineered" the design himself, ask him where he got his degree. "I have 3000 hours flyin'" is not an engineering qualification. Neither is "school o' hard knocks." This is serious stuff and deserves a serious answer. That seller wants YOU to bet YOUR life on HIS work. It damn well better NOT be guesswork.

Years of safe flying and lots of units flying TEND to show that a given design is OK, even without a formal design review. If all the ships in the field have total hours less than or equal to X, and some important piece is going to fatigue at X-plus-one, though, things could suddenly get ugly tomorrow or next month.

Bottom line: There is always an element of test-risk that you take on when flying an experimental aircraft. That doesn't mean that it's decent or moral for sellers to keep machines on the market that are KNOWN to be defective. Even putting these rotten apples aside, though, it's best to go into this activity with your eyes open to the risks that go with the territory, and be prepared to protect yourself by asking the hard questions.

[Cobra Doc]

Doug;
Believe me, I understand all that. I've been underwriting aviation insurance for over 7 years now. I specialize in the unusual: warbirds, rotorcraft, experimentals, seaplanes, antiques and one-of-a-kind aircraft. Anybody that made it to OSH this year probably got a really good look at a beautiful little one-off that I insure. I also believe that the law suit that RAF won in 1998 over the fatal accident in 1996 has made them feel that they are invincible. As always with anything else: "Buyer Beware." Trouble is, when somebody wants to sell me their aircraft, there isn't much left of it.
My wife and I plan to acquire a couple of aircraft in the next five years, a fixed wing, most likely a Sonex, for her to drive and a rotorcraft for me. I haven't decided if I want to restore a Bell 47 or build a Sparrow Hawk.

[StanFoster]

Cobra: I have stated many times how I feel about my RAF...mostly positive.

I feel mine with its stab is doing a fine job of flying for my needs. However....this rotor hub cracking concerned me almost instantly after reading Pauls post. There may be more to the story...and then they may not. But I know for one thing that my enjoyment that I have had in my RAF would be overshadowed by always wondering..."what if?" that hub bar was cracking.

I immediately got on the phone and I now have a set of Sportcopter blades being delivered this weekend. If I didnt like my RAF so much...I sure as heck would not have spent that kind of money.

Stan

[CLS447]

Good for you Stan ! Are they really ready to ship that quickly?

[Cobra Doc]

I can't fault you for that Stan. Given the statistics, and everything else I know about rotorcraft and experimentals, I can't see placing a million dollar bet on an RAF. Maybe next week I'll know more.

[StanFoster]

Chris: I have known about a barely used set of SportCopter blades for months that I was wanting to buy.

A friend of mine,...Bill Finnegan was going to buy them....and so I kept silent. But...I called Bill immediately after seeing Pauls post last night to see if Bill had bought them...he had not....and I jumped on them pronto. I have seen them..and the only reason the other person is selling these blades is because he needed the funds.

Stan

[GyroRon]

Stan keep us up to speed on how you like the sport rotors and what difference they make positive or negative in performance. The couple sets I have flown - a set I had, Barry Kropliens set on his Bee, and Chris S's on his Aircommand - Where all baby butt smooth and had nice float on landings. I love em!

[StanFoster]

Ron: I have been told the same thing about being smooth...and how they float. If they have as much reserve as my RAF blades...I will be tickled.

Anyway...my next flight will be with the sportcopter blades. I thoroughly looked over my RAF hub bar with a bright light today and could not see anything. Of course had I continued flying with this hub bar...I would have been using that ultra violet crack detector and very often.

I enjoy flying my RAF way too much.

Hey Ron....I made up my mind the other day about ROC 2005. I said I was just going to drive down there...but I just bought a nice trailer for my stairways and I will haul my RAF with "SportCopter" blades down there next year....you can count on it. :D

Stan

[GyroRon]

Stan.... can't wait! :) But just as I said in my email to you, I hope that you might be able to find a way to come to Bensen Days early spring 2005. ROC 2005 is a LONG time aways my friend!

[LARRYEBOYER]

sTAN, you mention you have a friend Bill Finnigan. Is htat the Bill Finnigan who lives in the Chicago area? If so he is a class act. I have met him at several gyro flyins. I e-mail him accasionally.

[StanFoster]

Larry: He is from Staunton, Il...in the southern portion. He gets around to most of the fly-ins and is always videotaping. He is one of the nicest guys I have ever met....would give the shirt off his back for ya. Class act....is one way to describe him.... :)

Stan

[Jerseywing]

Stan,
Can you give me some info on your HS? Who/Where did you get it from? What was the price ?

Thanks,
Mike

[StanFoster]

Mike: My stab is a Don Parham model. It has vertical winglets as you can see in my avatar photo. It has plenty of authority handling the tail end with my doors on.

Stan

[LARRYEBOYER]

That's him.He has a video of his last flyin attendance and said he would send me a copy. Right on the class act. I had breakfast with him one morning in Mentone. How are you coming with the older RAF you built? My new one is down to installing doors, wiring and safety wire. Soon! It even has that new face on the front with the long nose.

[StanFoster]

Larry: I will be messing with my other RAF soon. I am nearing completion of my new stairshop addition. I will probably be messing with it next month a little.

Stan