Proper Airfoil for Horizontal Stab ?

oldpilot

This RAF 2000 is FOR SALE
Joined
Dec 13, 2003
Messages
63
Location
Portland, Oregon
Aircraft
RAF 2000 + C150
Total Flight Time
170 +
This is my first post so go easy on me, Please.

I am purchasing an RAF2000 GTX SE FI soon and will need to put a horizontal stab (HS) on it. There is some info on several manufactured HS's available on this FORUM and other places. However, I find no info on the type of airfoil being used (maybe a trade secret??).

I would like to add the AAI stability augmentation kit but cannot afford it at this time. I see that many of you are happily flying about with a variety of HS's. Since I would like to get flying I wanted to see what the "conventional wisdom" of this group is on which HS I should start with and if I build one what airfoil should I use?

I am a Private Pilot (ASEL) and flew a SportCopter many years ago (ultralight) that I assembled from a kit - so I have SOME experience but it was a long time ago. I plan on obtaining instruction and an add-on rating for Gyro, so no need for the customary cautions.

Mainly I would like to generate some discussions on the proper airfoil to use and its setup on the airframe. I am sure many would benefit from this type of discussion.

I have 'lurked' for some time now and wish to thank everyone for their thoughts - it has been very beneficial for me to read the posts.

Oldpilot, out
 
Greetings old pilot,
You probably will get a lot of help here on the forum.
I will help maybe a little.
If you were to down load a copy of the gyro bee plans from Ralph Taggart's site,
there is info on building The watson tail group.
Although this may not be the exact thing you are looking for, you may get some good ideas as airfoil shape etc. Ron
 
Thanks Ron,

I think I posted this thread in the wrong spot on the FORUM but don't know how to move it to the Enclosed Two Place. So I guess people will see it??? (you did :-)

I will check out Taggart's site.
 
Raf thrust line

Raf thrust line

Steve we lowered the thrust line by 6 inch on our RAF with good results plus a good stab sutch as Stan has.
 

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Steve, are you buying a kit or an existing RAF? If a kit, why not just go for the Sparrowhawk? It costs slightly more, but you get way more than your money's worth over an RAF kit. If you're buying an existing gyro......never mind.
 
John,

Do you have any photo's which show more (any) details on how you modified the CLT? The photo you posted doesn't show the tail section (underneath) very well due to the shadow. I would really like to see what you did to modify the tail boom but the distance of the photo doesn't allow it. It looks very professionally done however!

Old Pilot
 
KenSandyEggo,

I am purchasing one that is already built.

I have been following the SparrowHawk since last year. I even went to Puyllap, Washington to the airfair and saw their partially constructed model (and sat in it). The only post I read on this FORUM of a completed one (not from an AAI dealer) said it had not lived up to the Mfg. claims on performance and seemed to be a heavy RAF2000. There is a noticeable (sp?) difference in interior headroom and width but the manufacture and testing on them has been so painfully slow I think one could argue that they are far from working the 'bugs' out. By my count there are only 2-3 completed SparrowHawks anywhere and all are in "testing" phase.

There has been a lot of 'hype' about the SparrowHawk but most of it comming from AAI to encourage sales. The real test of the SparrowHawk will come from members of this FORUM who begin to fly this Gyro. When a hundred or so of them have been flying a year or so in many different environments year around - then I think we all can draw a more rational ( and independent) opinion of the SparrowHawk.

Personally I like the SparrowHawk, but it is on the expensive side to purchase and out of the range of the average 'backyard' Gyro buyer - in my opinion. I will save my money and purchase a Talltail kit from them someday, if the price stays down and they are still in business.

Which brings me to the final point on the SparrowHawk, since you asked me about it. Groen Bros., the parent company has some enormous debt and their stock value has dropped over the past few years from several dollars per share to a current value of 18-25 cents per share! A lot of investors have lost their shirt and the insider trading looks like more selling of the stock than buying. No one is talking about that...these are all public records available on the internet. Even though I truely hope the SparrowHawk proves to be a success and an advancement in the Gyro field I worry that their optimism at AAI/Groen Bros. and the marketplace don't hit head-on in a train wreck!

Old Pilot
 
Vancraft Rotor Lightning and RAF 2000 horiz. stab

Vancraft Rotor Lightning and RAF 2000 horiz. stab

oldpilot said:
This is my first post so go easy on me, Please.

I am purchasing an RAF2000 GTX SE FI soon and will need to put a horizontal stab (HS) on it. There is some info on several manufactured HS's available on this FORUM and other places. However, I find no info on the type of airfoil being used (maybe a trade secret??).

I would like to add the AAI stability augmentation kit but cannot afford it at this time. I see that many of you are happily flying about with a variety of HS's. Since I would like to get flying I wanted to see what the "conventional wisdom" of this group is on which HS I should start with and if I build one what airfoil should I use?

I am a Private Pilot (ASEL) and flew a SportCopter many years ago (ultralight) that I assembled from a kit - so I have SOME experience but it was a long time ago. I plan on obtaining instruction and an add-on rating for Gyro, so no need for the customary cautions.

Hi Steve! Gary Kaminski flies his RAF 2000 out of Chehalem Valley airpark in Newberg and he has added a horizontal stab to his machine. You could ask him to view it to see what the airfoil shape looks like.

I'm one of the two fellas that came to your home back in '93 and bought your Rotor Lightning.

That is it in my avatar photo above! It is a shot someone took of me landing at Leo Boyer's grass strip in Gaston during one of our chapter meetings.

I thought you'd like to hear what happened to it over the next several years.

Dan (the other fella) bought it from you and taught two of the five guys who became joint owners of it to fly a gyro. Two backed out, one citing pressures from wifey since they had a couple of little children and the other admitted he was scared to leave the ground.

The third guy was rotary forum member Julie's dad, Dave Richardson. He and Dan couldn't get together on the same schedule for training, so he also didn't fly it.

I and the other guy (Jim Ginn) flew it a lot over the next year or so.

I had 75 hours in it and Jim over 100. Last I heard, the hour meter showed around 240, when Jim took it to Colorado. It had 22 on it when you sold it to us. It was hangared at the Estacada airport.

The gyro saw the scenery over the Columbia Gorge, Mt. Hood, the coast at both Siletz Bay airport and Tillamook airport, and much of the area between. It was flown to these locations, not trailered.

We did trailer it to the PRA chapter meetings at Scappoose.

I had four emergency landings in it, and Jim two. No damage on those six landings other than the plastic wheels (that helped make it an ultralight) developed cracks around the hub before we replaced them with aluminum ones. Anyone who is interested in reading about my four emergency landings and my foolish mistakes that led to three of them can read the past newsletters on the Chapter 73 website located at: www.pra73.net

Jim G. bought Dave and I out of our ownership shares. He lost his job of over 20 years as a maintenance man in one of the paper mills there at Willamette Falls in Oregon City, and with his severance package, moved to Colorado Springs to open up the first Papa Murphy's Pizza franchise there.

He told me that he couldn't get out of ground effect with the 503 dual carb (we added the second carb after we had been flying it around for awhile), even with some help from local Colorado guys in getting the carb jets changed for the altitude.

He trailered it back to Oregon, where it was sold to a friend of Leo Boyer who had liver (?) cancer and had lost his medical. He and Leo flew their respective gyros together around the Gaston area, where that other guy had a grass strip on his property.

This other guy (don't recall his name) succumbed to the cancer and his wife sold the gyro to someone in the Oregon City area, two or three years ago. Don't know of it's whereabout since then...

Kevin
 
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Kevin,

Wow, what a great reply! I never did know what 'really' happened to that UL Gyro. You brought back some good memories. Someone had told me years ago (can't remember who) that the gyro was crashed soon after I sold it and that is what I believed all these years.

I have sent two email to Gary K in the past month and no replies from him??? I would like to get a look at his tail feathers and Gyro in general but he seems to be AWOL at this time.

I am not having much luck with Ralph Taggarts tail feathers - seems his website is off the 'net'.

I keep hoping for some of the technophiles on this FORUM to give me some specific airfoil data I can work with.

Oldpilot
 
Steve,

I've heard some griping that Groen Brothers are better at raising capital than developing aircraft, but they appear convinced that the horrible statistical safety record of gyroplanes is part of their problem moving forward. According to their press releases, that is their reason for doing the SparrowHawk project, to provide a safer alternative to the RAF. If they succeed to raising the safety level within the sport, or even succeed in getting prospective buyers to understand why some gyroplane designs are unstable, they may pave the way for Hawk-IV sales.

As far as the design being proven, much of the SparrowHawk airframe looks very similar to the RAF. The cost is also about the same. Most builders have $30K-plus in their RAF's, and the SparrowHawk is a more complete kit.

Even if you're buying one already built, you might find Gary's builder's site useful. There are some parts on your machine you may want to upgrade for safety. Gary's site: https://home.att.net/~raf2000owners/home.htm
 
Proper Airfoil for RAF 2000/Groen Bros. problems

Proper Airfoil for RAF 2000/Groen Bros. problems

Paul,

Good to hear from you!

I do not know how good Groen Bros. is at raising capital but their public record indicates that one of their major problems is SALES. They seem to have poured quite a bit of time and money into Research and Development (R/D) but can't get them sold. It just defies me, because they seem to have the right idea and highly qualified people working for them and running things??

I do feel that they are taking too long to get their product to the consumer and someone made a VERY poor decision to RAISE the price of their SparrowHawk from $27,300 to over $30,000.00 recently. AND I would like to know why they priced their RAF 2000 Stability Augmentation kit at ~$5,000.00 ?? I do not see any FIRE SALES or promotions or anything to stimulate SALES. I would think the more 'Birds' they have out there the more the demand will be - but what do I know...everyone's a critic.

However, to look at their Balance sheet you need to be sitting down. One must wonder how much longer the bleeding can last.

The one thing I can say they did to stimulate sales was to develop the Stability Augmentation kit (SAK) for the RAF 2000 - to begin the attempt to improve the Gyro safety record. That inturn should stimulate sales for their SparrowHawk and Defender (AND THE RAF 2000) - in theory. The problem is the SAK is too expensive and will not have the desired impact on Gyro safety stats until it is in wide use and for more Gyro models than the RAF 2000 (in my opinion as a consumer).

I believe the SparrowHawk is going to turn out to be a good 'Bird'. But I also believe it will be an oversized RAF 2000. Its larger cabin will create more DRAG AND WEIGHT...so they increased the horsepower. So now you burn more fuel, go approx. the same speeds and have more elbow room. Some people will want that some will not.

I do not think it is a more complete kit, by the time you spend ~ $31,000 to get a kit delivered to your door, you still need to assemble it and add NAV/COMM and Transponder at the minimum. So add ~ $3-4,000 minimum. THEN how many thousands of $$$ for a Gyro rating @ $135.00/hr dual??

My point is that NO ONE will do well in the two place enclosed Gyro market until they get their prices down to where the average Gyrohead can afford one.

Just so I don't get too much hate mail from GNBA and AAI I want to make it clear I LIKE your 'Bird' and hope it sets a new standard. However I think it is too expensive and is untested in the real world as of this writing.

I hope we can get together one of these days - I see you are VP of Chapter 73 - - Congrats!

oldpilot
 
Kiwi John,

Thanks for directing me to the New Zealand modified RAF. Excellent photos! What airfoil was used for the Horizontal Stab?

Oldpilot
 
Oldpilot: Its well known I love my RAF with my Parham stab. It handles very nice with the doors on,....I flew home over 80 miles today with lots of thermal activity and never once was uncomfortable. It was a real nice flight.

Good luck with your RAF and I assure you that you will be very pleased with it.

You can e-mail in private for more chit chat if you prefer. I would be happy to mention some names of high time RAF pilots that gave me the confidence to go buy one for myself.

Stan
 
StanFoster,

Thanks for the info Stan. I appreciate knowing I can contact you for advice once in awhile.

Cordially,

Oldpilot
 
Oldpilot: Gregg Gremminger took photo of our trio of RAF's today at the Shelbyville, Il. fly-in. Each of these RAF's has a stab..but each one is different.

Mine is the RAF in the front and has a Parham stab on it and it is works very nice.

The RAF in the background is Jeff Millburgs and he has a Kenny Janulewicz stab.

Dan Probst is piloting the nearest RAF and has the stab from New Zealand..I think its Paul Bruty's design....Am I correct Paul?

Anyway....they all fly nice and we all three get some serious hours in our logbooks and go places. :D

Stan
 

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oldpilot said:
Kevin,

Wow, what a great reply! I never did know what 'really' happened to that UL Gyro. You brought back some good memories. Someone had told me years ago (can't remember who) that the gyro was crashed soon after I sold it and that is what I believed all these years.

It was ground looped a few months after you sold it. It was done by the guy (Todd) with the "wifey-says" problem. He had dual training with Jim Digaetano in his side by side Air Command in Las Vegas just prior to the incident. He had been soloed.

He was taxiing our gyro at Scappoose at one of the chapter meetings, going rather fast balancing on the mains. One of the wheels rose up higher and he became airborne a few feet high. Jim Vanek was the only other person to see what then occured, as he was flying by overhead.

Todd became crabbed, and he panicked, chopping the throttle. It came onto the wheels sideways. He said that he immediately knew that he should have added throttle and straightened his heading with the rudder pedals, then reducing power and settling onto the runway.

His only injury was a small cut on his hand from standing the gyro back up onto it's wheels. The fiberglass fairing had some splinters from the ground loop that bit his hand.

The gyro was down for a couple of months getting it's few bent parts replaced. Most of the wait was for receiving a new set of rotorblades and prop. The fairing was sanded a bit, and I think the control rods were replaced, along with part or all of the rotor head and rotorhead cheekplates. A new horizontal stab also. That welded airframe sustained very little damage.

Are you still out along the Willamette River there in Wilsonville?
 
Hi Steve,

I would like to invite you to come fly in my AAI modified RAF and my SparrowHawk before you go to the trouble to buy RAF. I remember visiting with you at the NW Conference and would like to get you more information about the gyroplane industry as a whole to you. What you do affects all of us.

I know GBA has some debt and as an invester for over nine years I know that it is a normal situation for a company that is bringing new technology (In this case old technology that has be updated) to the market.

A major portion of dept is to the dealers such as myself. It is listed but won't be paid back untill we start selling Hawk IVs. The amount of debt is not high compared to other technology startups. (Like Eclipse or software startups) I have had purchase order requests for 34 Hawk IV's from law enforcement agencies ( to be operated under the public use law) in my dealership alone. That was over $36,000,000. They were to be funded by the Home Land Defense budgets. I believe they were left off because of the accident rate of gyros.

The issue about accident rates affecting our sales is real. From the 1920's through the 1950's the death per 100,000 hours in gyroplanes was the same as the rest of general aviation. From the beginning of the 1960's through 2002 the rate of deaths pre 100,000 hours in gyroplanes was 23 times that of other general aviation. It has now starting to drop. The British government said that the high rate was caused by the thrust of gyroplanes raising substantialy above the center of gravity, lack of substantial horizontal stab, and the lack of a formal training program for new pilots. The British have now banned any new gyroplanes that have the thrust more than 2 inches above the center of gravity, not enough horizontal stbility and have instituted a much more stringent training program for new pilots. They have demanded that the testing procedures prove stability. There goal is to get gyroplane accident rates in line with the rest of general avaition. (That should be our goal too. It sure is mine!!) You can find this report in the reported accidents on this forum. GBA set about the same program several years ago after we found such difficulty in getting issurance and getting aviation agencies to take our work in the gyroplane part of avaition seriously.

I have found it impossible to find issurance for training because of the high rate of accidents. We have instituded a intensive formal silibus for training developed by Terry Brant and it is the standard for all the AAI dealers.

Gyroplanes as a part of aviation will never be excepted by general aviation until we as a whole take the steps to get the accident rate on apar with the rest of general aviation.

Steve, you said AAI is prejudice about our product. I totally agree with you, but for a different reason. My success in making a living depends on you staying alive. I want you to fly our products because I know they will keep you safe. Untill you and the majority of the rest of the gyroplane industry take the steps to get the training that is necessay and buy and build centerline thrust aircraft, we won't get the recognition from the rest of the aviation community that we should have.
 
Randy,

Good to hear from you...I figured it wouldn't be long before someone from AAI contacted me :D .

I have had several phone conversations with you and now this FORUM reply. In each case you have impressed me with your honesty and integrity and politeness (even when I brought up the subject of Groen Bros. Stock dropping in value).

I am likely going to take you up on your offer to visit your facility and fly both machines. At the very minimum I will need to find an instructor and I am sure you could make a recommendation in that area.

I am also interested in the training syllabus Terry has created, that you mentioned. SAFETY is my primary concern too! I want to be a part of the solution - not the problem (I know that sounds corny but it is really how I feel).

I was unaware of the accident statistics you report AND am very surprised the accident rate is so remarkably high. I was also unaware the British Government had gotten so strict with their Gyro Airworthiness requirements - 3 cheers for them!

It is the lack of insurance availability for Gyro instruction that caused me to find a deal on an RAF 2000 that I just could not turn down. I can only imagine the 'pile' of Liability waivers you would have me sign to take instruction at Auburn, since no insurance is available to you. When will your RAF 2000 Stability Augmentation Kit (SAK) go on sale? Will you give me a BIG HUGE discount on the SAK if I take instruction from your instructor? Please do not answer that - I am just poking a little fun.

As I have repeated several times in this FORUM I like the SparrowHawk and its CLT and several other aspects of it - BUT it needs to be flown and tested in the real world where the real 'bugs' can be sniffed out and corrected. You are a real believer in SAFETY and I would not ask you publicly to say anything against your product. However, can ANY aircraft so new to the marketplace be considered safe yet - I think not! Does that make it fall into the UNSAFE category? ABSOLUTELY NOT! It just hasn't had time to prove itself yet - and that is what safety is all about...just my opinion.

If you would send me some info privately on everyone's availability at Auburn I will try to work a visit in.
 
Kevin Richey,

Thanks for the info and unraveling a 10 yr old mystery for me! I sold the place in Wilsonville (12 acres) and moved to the Stafford area and 3.5 acres.
 
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