Greetings from Tucson

[spaceman spiff]

Hi guys and gals,

Just got an old Air Command auto gyro (pre- horz stab). It has been sitting out in a friends back yard for 15 years, so it is a bit weathered, but has only a few flights on it. Don't know much about these beasts, just seen a few pics on PRA so i have a whole bunch of questions to ask before i start tearing it down for restoration.

are there still folks flying a 20+ year old one like mine?
does air command have a kit so i can add a stab?
longer tail boom?

anyway thanks in advance for any advice.

Spiff

[gyromike]

Welcome aboard Joe.

Yes people are still flying older machines (provided they're in proper mechanical condition)
Yes, you can (and should) get the stabilizer kit from Air Command.
And yes, you can (and should) get a longer tailboom from Air Command.

But if it's been sitting out in the weather for 15 years, you need to find an experienced builder in your area to help you go through it completely.

[PW_Plack]

Spiff,

At one time, Air Commands were banned in England for a high fatality rate. The company responded, did the right thing, redesigned to solve the major aerodynamic issues, and offered a retrofit kit to owners at a very low price. I believe it's still available.

You may be looking at replacing some parts anyway. I'd start by seeing if the upgrade kits are still available. I think they were about $1200 US.

[spaceman spiff]

Banned?!!! :eek:

Not a comforting word to hear as a beginner! :D

[GyroRon]

You need to completely tear the gyro apart. Clean and inspect each tube for cracks and corrosion. Then repaint those tubes.

The rotor head should be sent back to Aircommand to be rebuilt.

The engine should be shipped to a rotax certified mechanic to have all the seals and gaskets replaced. This is very important. A bad seal or gasket and the engine will run lean and will quit running. I would say the muffler will likely need replacing as well.

You need all new tires and tubes. New bushings in the control stick assembly under the seat. New rod ends for the control push tubes - these need to be the type used for aircraft and can be purchased from Aircommand.

All the nuts and bolts should be replaced for safetys sake. Rudder cables inspected, all new fuel lines. New rubber carb sockets. Carbs rebuilt.

The most important part of the rebuild is adding Aircommands Center Line Thrust installation kit. This involves raising the seat and front end higher up the mast and flipping the engine so the sparkplugs are on top. I will attach a pic of a older aircommand like yours that has had the CLT conversion recently done to it.

You also need to order the extended tail boom and horizontal stab kit.

The prop is totally shot. Replace it with a nice Ivo or Warp Drive prop.

Measure the blades by themselves and then the Hub bar. 25 foot blades would be the longest you would want to use on that light of a machine.

This gyro as configured is very unstable. It can easily bunt over. The CLT kit is very much a needed item for this machine. I can't stress that enough. With the CLT kit the gyro is very nice and safe - as long as the rest of the restoration is done properly.

None of my business, but I hope you didn't pay much for that thing!!! It will need at least 3000-4000$ worth of professional work and parts, and alot of your time - sanding, painting, cuting, drilling, shipping, ordering, etc... etc... to get it airworthy.

[ben]

hey joe welcome to a great sport

[barnstorm2]

are there still folks flying a 20+ year old one like mine?
does air command have a kit so i can add a stab?
longer tail boom?

anyway thanks in advance for any advice.

Spiff

Spiff,

You are getting good advice here and in Chris's thread.

I have a few tidbits to add to lighen your heart!

First if you get the CLT upgrade kit you will get alot of new parts in it as well as a new keel so that is likely worth every penny. During the CLT-upgrade you can do the restore killing 2 birds with one stone.

Rotor-Head has made a FANTASTIC time-lapse video (posted here on the forum) of him doing this very upgrade on a machine of the same vintage as yours.

Have you called Doug at AirCommand yet?

Restoring an older gyro is more work then building a kit. I know because I have had to do this.

Do you have the old assembly manual for this gyro? If not AirCommand will sell you one. If they don't have any left email me and we can make arrangements to get you a copy of mine (I think I can find it...).

Make sure you crimp the rudder cables with the proper tool. Personally, I would have the crimps inspected by an experienced builder before flying (along with the rest of the craft).

You can ship the rotorhead back to AirCommand for rebuilding. I did so with mine and I was very happy with the results.

Rebuilding the engine could be expensive so shop around. If you buy a new one you might be able to sell your old engine for parts here or on ebay to recoupe alittle cost.

I have a few spare parts around so if you have a want list send me a copy and I will let you know what I have.

Here are picts of mine when I got it and now (single place). I did not do a full rebuild on the single place because it was well stored. My 2-place however was another story.

If you (or anyone) has some spare brake pads for this gyro please let me know. I need some or a source for some. AC no longer stocks them.

[spaceman spiff]

Thanks guys. Sounds like a big job ahead of me. Good news is the gyro was given to me. As soon as i have my trailer set up for it ( i have an old 4x8 which will have to be modified.) i can haul it home and start tearing it down. still don't have the manuals, my friend has a box of info stashed somewhere, but hasn't been able to find it.

Got an email from Doug @ Aircomand this morning, got some basic info on the stab and centerline upgrades. definatly gettng the stab and longer boom, but
Man that centerline upgrade is butt ugly! looks like something out of the Dr. Seus books! :D

[scottessex]

Contact me by PM before you pay anyone else to recondition your engine.

[PW_Plack]

Space,

Ugly is as ugly does. Ever see how ugly a black, smoking crater is? I'll see if I can find a link to the story of the Air Commands in England...

[pwendell]

T
Man that centerline upgrade is butt ugly! :D

Ugly is as ugly does.

Forest Gump

Seriousely, the CLT upgrade will greatly improve the gyro's handling charecteristics and make it much safer and easier for a new gyro pilot to learn on. It's not nearly as ugly as a set of bent blades or a big medical bill.

[spaceman spiff]

Greatly improved handling is something i would be willing buy that for.

Did a littel research a few days ago on gyro crashes. 19 serious crashes between 1996 and 2001 about half of them were blamed on instability. All of those were on gyros that had no stab. FAA was pushing for manditory stabs so it apears to me neither the FAA nor the data is pointing to having a lower CG as certain death, but the stab is the important thing, so i was inclinded to get that and leave most of the rest alone.

i was looking at the frame and wondering about a few other mods related to CG i could do. Thinking about getting rid of the under-seat extra fuel tanks. Maybe turning the engine around so the bulk of the engine is higher (cylinders hang down presently), possibly raise the seat a few inches... maybe switch to a smaller diameter 4 blade so i can place the motor a few inches lower.... any opinions of how any of those mods would play out for handling? if i can get reasonably good handling and still have reasonably low CG that seems like the thing to do..

Are the ones with high seats more vulnerable to tipping over on landings?

Thanks for the opinions guys

verrry nice avitar ben! :D :D

[MikeBoyette]

Spaceman,
If you fly that without the CLT you are risking your life. A gyro is not supposed to be pretty. If you are concerned about looks over fuction then I suggest you sell your aircraft. I for one do not want to have to deal with someone else giving gyros a bad name. I have personaly witnessed, and was first on seen of a fatality in the exact aircraft you have. In closing I do not want to come off like a know it all AS*Hole, but this is you life you are dealing with. The best advice is go to CLT. These are aircraft that should be breaking ground at a slow speed and landing at near zero ground speed so tip over should not be an issue.

[Friendly]

Welcome to the forum Spaceman, it sounds as though you are doing the necessary research to upgrade your machine to a reliable aircraft. I encourage your to join PRA and your local chapter. Make some flyins and get training from a qualified trainer. By the way, great price on the gyro. May I ask why your friend lost interest in the gyro?

[spaceman spiff]

I asked him the same thing twice. All he said was He had gotten laid off from a good job a number of years ago and couldn't afford it anymore. Currently has a repair job in the same company i work for. Repair doesn't pay well (i know this first hand). Most likely there is more to it though, maybe he just tried it, it was fun experience but decided not to continue. Iv'e done that i time or two. Maybe he doesn't want to admit he is a wuss? He has cautioned me about it being extreemly dangerous (and no doubt all you guys agree), so he is not misrepresenting it as just pure safe fun.

We had a hot air balloon accident here a few days ago, two died. One of my RC buddies was hit by a model airplane and died a horrible death a couple years ago. Truth is nothing that flys is safe..

Anyway, i have plenty of time to sort it all out, make informed decisions. I see a lot of low slung gyros on these pages, so obviously not everyone agrees on the importance of the CG issue. Will consider it very carefully though, just looking at options and gathering opinions and data at this point. I see no need to go rushing thru and flying what i have, but i am cautious about just hauling off with the credit card and buying everything anyone says i should. Sorting it all out is part of the adventure of it all.

[GyroRon]

Okay call me a asshole.... cause I don't like to beat around the bush, or sugarcoat things.

You are looking for a excuse not to do the most important upgrade you could do to this machine. That is simply RETARDED.

Understand that the stab DAMPENS the airframe in pitch. It does NOT counter the force of the engines thrust trying to push the gyro over into a power push over in a machine where the thrustline is several inches above the vertical CG. The stab makes it harder to get into the conditions that can cause a power push over, but it DOES NOT Prevent or Stop it from happening.

Power Push over can not happen when the thrust of the engine is pushing directly on or slightly below the vertical CG.

Do you not understand that Power push over is one of the most fatal traits gyroplanes can have? Once a power push over starts, you can not stop it and you are Certainly going to die. Even at a low altitude.

Why have a gyro that a power pushover is possible in? Some people do have it because either they can't afford the time or money to fix their gyro, or they feel they will never get into a mode of flight that a power pushover is possible. This is called rolling the dice, and it is your life that that roll decides, everytime a HTL gyro goes up. With CLT the odds of a bunt over is zero. How can that be ugly?

Look I am not trying to be a asshole and I hope you take waht I am saying with a grain of salt. You got alot of work ahead of you and you might as well put this gyro back together in the most up to date and safe way as possible. It could save your life.

[cgmg]

Joe,

Listen to everyone, and get the CLT kit. I have it, and will not fly an Air Command without it. I bet Charlie will heavily lean on you to get it, if you take lessons from him. He encouraged it for us, and it is worth every penny we spent for it. The machine is more forgiving to you as a novice pilot, and removes the constant danger of not reacting to a pitch excursion in time. In over 100 hours of flying our machine, I've yet to encounter a situation where I have had to reduce throttle immediately, or correct for, a pitch excursion. But understand that I don't fly flat-out, and reduce my airspeed if it gets turbulent. Flying our CLT is much more relaxed than when trying to fly Charlie's machine, which is not CLT.

Also, if you need it, I still have the original assembly manual, and the CLT conversion manual. I would be happy to run off a copy, and send it to you, at no cost to you. Just let me know by private email, and it's yours.

[spaceman spiff]

There's no reason for me to call a guy who is looking out for my best interest an asshole. You all have and will continue to have my respect and gratitude, whether i agree with you or not. At this point neither, only cautiously skeptical for the reasons listed below:

I am a big believer in statistics.

The FAA report catagorized the 19 serious crashes reported between 1996 and 2001. Thats ~3 per year(all causes combined). Seems like a low number. How many gyro guys are there? I can't seem to get a number, but i keep hearing there are quite a lot. So when anyone tries to convince me that flying any common gyro that has this or that is certain death, from a statistics point of view, i will be justifiably skeptical of that claim.

The FAA catagorized those crashes and determined that half of them were due to instability. The FAA found that in ALL of the cases of the crashes due to instability, the aircraft HAD NO STAB. So is it safe to say that statistically there is a corelation between a stab and serious instability? Yes, obviously.

The not so obvious thing to consider is that of the many non-centered gyros that had a stab, NONE of them had a serious crash atributed to instability for any of those 6 years.

According to the FAA report, and the statistics, a good stab is enough to fix the problem. So i will take any claim that i will certainly die for not doing this or that with a grain of salt.

I will however be very interested in handling. if you wish to convince me that i will enjoy the experience more for getting this expensive and ugly upgrade. i will consider it, but I see no basis for drama, and i refuse to be motivated by fear.

What i plan on doing is weighing all the components of my bird, verifying for myself where the CG is in relation to the thrust line with me on board (tall, with skinny leggs, makes a difference no doubt) and see how big this moment really is, and decide from there.

[PW_Plack]

Space,

If your friend stopped flying because he scared himself, it may not be because he was a "wuss." Lots of "brave" people won't fly the old low-rider Air Commands.

Don't confuse the terms "stabilizer" and "instability" in these reports. Adding a stabilizer to an older Air Command machine doesn't make it stable. The full modification kit will. The H-stab only makes an unstable pitch oscillation reach a critical point more slowly, allowing most people to survive it.

[Rotor-Head]

Sounds like you are where I started.... I had an ALL ORIGINAL 1985 447. Here's my AC and its evolution to a modern machine: http://www.rotor-head.com/pictures/mygyro/mygyro.html

[spaceman spiff]

Nice presentation Rotor-head, I see what was meant by getting a lot of parts with the kit, turns out i may need a new prerotator cable due to rust (unconfirmed ).

I see a nice JR RC heli in on the shelf! I'm a raptor 50 guy, also have a freya 90 on the bench. Tons of fun! Do you still fly RC, or has that been replaced by the bigger bird?

[Rotor-Head]

Nice presentation Rotor-head, I see what was meant by getting a lot of parts with the kit, turns out i may need a new prerotator cable due to rust (unconfirmed ).

I see a nice JR RC heli in on the shelf! I'm a raptor 50 guy, also have a freya 90 on the bench. Tons of fun! Do you still fly RC, or has that been replaced by the bigger bird?
I actually had the Vigor .60 in the field across the street from my house day before yesturday. Although it gets flown A LOT LESS than my gyro, I still do enjoy it. My 2 1/2 year old loves to watch me put a hook and line on it and pick up his big-wheele bikes and toys in the back yard and fly them around. Then I land them in the corner of the yard. It takes a lot longer, but is much funner to pick up and clean with an R/C helicopter. I used to have a bunch of FW as well, but got rid of the ones that survived my abusive pole dodging.

Shawn

[spaceman spiff]

Well Gents, There are just too many of you happy owners of converted low riders, to ignore any longer. I have fought my best fight and lost (or won depending on how you look at it). Will be ordering the DR Seuse special CLT kit shortly. Thanks for your input. Pics to follow. :D :D

[Rotor-Head]

You'll be happier and feel better with a CLT gyro... At first I thought they looked a bit funny, but now I look back and I think they look just as good. I think there's a psycological attraction to a safer machine.

[bartc150]

If you want to do a real world search of accidents, do one with an HTL machine such as air command, or bensen, then do one on a CLT machine such as dominator. Dominator has seven recorded accidents on the database, 2 which were fatal, both of them were caused by untrained pilots. Not one Dominator crash was due to an unstable craft, PIO, or PPO. this alone should tell you how important a stable machine is. Spend a little more money now so you can enjoy a life long journey as a gyro pilot.

[GyroRon]

2 fatal Dominator accidents? Please fill me in, as besides tip overs on the ground, I was not aware of any Dominator " crashes "

[spaceman spiff]

http://safecopter.arc.nasa.gov/Pages/Mission/Accidents%20by%20Mission/GyroAcc.html

I noticed there are no power pushovers listed.

1 report on that link of a gyro porposing. RAF 2000, one of those no stab models isn't it? hmmmm.

No power pushover?... Where is this nasty beast, killer of thousands hidding? :D

[GyroRon]

http://safecopter.arc.nasa.gov/Pages/Mission/Accidents%20by%20Mission/GyroAcc.html

I noticed there are no power pushovers listed.

1 report on that link of a gyro porposing. RAF 2000, one of those no stab models isn't it? hmmmm.

No power pushover?... Where is this nasty beast, killer of thousands hidding? :D

Any accident where they list the tail and blades, or prop and blades made contact is a power pushover.

[Rotor-Head]

Hey Shawn,
Did I miss it or what? I've been eagerly anticipating your reaction to how your new CLT modded gyro flies...so...are you happy??
No, I've opnly done 1 short hop down the runway woth a short climb and the weather has been bad ever since. I will be flying this weekend FOR REAL. Details to come.

[spaceman spiff]

The closest thing i saw like that listed was Oct 23 2000. witnesses say they saw something fly off the gyro before decent. No mention of fliping over, part of the rudder was broken off, but doesn't sound like a PPO...

Another where the gyro is in a banked turn and noses down, no flip though, so... did the guy just not keep the disk loaded thru the turn? wouldn't that be a serious no no for any gyro? no matter where the thrust line was?

Please look them over and show me an accident that is clearly a PPO.

I noticed a carter copter accident where the vert stabs were taken out by the rotor on a rough landing. Sunday, March 25, 2001. blade strike, but clearly not a PPO, so your criteria for PPO crash evidence might need a littel refining.

I don't doubt that it is physically possible, but nothing in those logs clearly matches the description you gave of what you say will certainly happen to me if i fly a low power low rider.

[GyroRon]

I don't say it will certainly happen to you if you fly a HTL machine Spiff. I am telling you the Possibility exists if the gyro is HTL. The possibility does not exists in a CLT machine. Basic science and physics stuff.

Your making your flying decisions based on accident reports? these reports are rarely ever true. The investigators know little to nothing about how a gyroplane flys at all. Some reports show the rotor is powered by the engine in flight, when we all know that is not the case with a gyro.

I am telling you, if there is any indication of the blades striking the tail or prop while the gyro is NOT on the ground - such as a landing - then the gyro was in a Bunt over or power pusher over mode of flight.

I got to go to work, and don't have time to look through your report collection. But what I do have the time for is to tell you to learn more about gyroplane aerodynamics before you make decisions about how you want to set up your gyro. Right now I can tell you have little to no real grasp of it. Blades DO NOT need attention to stay loaded in a turn. If a gyro noses down in a turn that is classic PPO.

I am telling you to put the CLT kit on, because it is simply a safer and more efficent way to fly. You seem to be looking for any and every excuse not to put the kit on based on the looks of the gyro with the CLT kit....... what a backwards way of looking at things Spiff! A Gyro is not a painting to be hung on the wall, it is not your girlfriend or wife, it is not a thing of beauty in any way. It is a machine, and it should be made to be as safe of a machine as possible, and looks come second.

Me personally, I much prefer the looks of all the CLT gyros over all the low riders. This is simply cause I find beauty in the fact that the machine is PROPERLY designed and PROPERLY rigged, and is as safe as could be for that type of machine.

If you are concerned with looks more than having your machine set up in the safest possible way, please do me and you and everyone else a favor and sell the gyro to someone who will do the right thing and take the money and buy a classic car or a motorcycle or a fancy painting to put on the wall.

You know alot of people also taught themselves to fly. Does that mean that you should base whether you teach YOURself or get flight lessons based on accident reports?

Can you pick the best seat on a airliner based on accident reports?

etc... etc.... Just do what we know is the best for you and you will have a great time flying your gyro.

[spaceman spiff]

" Blades DO NOT need attention to stay loaded in a turn. If a gyro noses down in a turn that is classic PPO. "

Do you not need to pull back on the stick like in an airplane or heli?

[Rotor-Head]

You should just always keep positive G's on the gyro (rotor system), never negitive or zero. If a gyro in a turn has a negitive G load on the rotor disc, it is a PPO, otherwise is not possible.

[KenSandyEggo]

Shawn, every time I get to one of your posts and see your Avatar, I get the "willies." I see those white flaps under your face and for a second I think I'm seeing Sister Mary Dominick who used to beat the crap out of me with a ruler or hand broom.

[Rotor-Head]

Funny... just to give you a better impression.. here is the original!!! A picture of Me and the Sikorsky S-61 "Sea King" tail rotor blades that hang in my son's room.

But I thought I looked more like Elvis!!!

[spaceman spiff]

If i was in a CLT, and disk load went to negative because; i nudged the stick, hit the edge of a nasty thermal, a controll link broke or jammed, banked too much, or any of the other reasons that that might occur, are you saying nothing bad will happen?

[Rotor-Head]

It's a powered machine, that flys. Something bad can always happen (like in a car, boat, bike, or even sitting in your lazy-boy watching TV), but there are things in place to minimize that. CLT is one of them.

It's not about a "fool-proof" machine, it's about the harmony between a "safe" machine and a compitent pilot.

[spaceman spiff]

Keep in mind that i am a 225 pound guy in a gyro/engine reported to be a littel whimpy as far as power and lift capacity. that means my disk is going to have to be farther back than some, and engine is going to be pretty much maxed out to get off the ground. As i see it the risk of power push over is pretty low under those conditions becuse there isn't much power left to accelerate and the amount that it would have to tilt the rotor would be greater than if i was 150 pounder. Does that make sense? if not why not?

Been looking at the discussion in the aircommad section saying the CLT has better lift capacity, In my veiw, if there is a reason to get the CLT that is it.

Would like to hear why the CLT would lift more.

[Rotor-Head]

I posted this last week:

As I understand it... in a HTL machine, the thrust from the propeller is trying to push the nose down, therefore requiring the rotor to be tilted back slightly more, causing more drag. When the thrust is centered, the nosedown tendency does not have to be compensated for by back-preasure and the rotorblades would fly a bit more level reducing some of the drag making the machine more efficient. Picture an open ended right triangle flying into the wind, now make the base much more narrow and it will be more efficiant through the air. Does that make any sense??

This is just my opinion. Someone please correct me if I am blowing smoke.

[barnstorm2]

Spiff,

At 225 you might be too heavy for that machine.

With a full tank of fuel, my 190 lbs and a hot humid day above 85F my 447 has dangerously little power and lift.

Under 80F she is fine with me, though still a slow climber.

If and only if you convert to CLT you can get Dragon Wing rotorblades which will lighten the craft and provide better lift performance. However, you must do the CLT upgrade before using the DW blades or the thrust offset will be more.

[spaceman spiff]

Ack! Except for winter it is 80 - 110 here most of the year. Presumably altitude is important too. I'm at 2200 - 2500 feet. Is that low enough that it will help me?

Not sure what engine i have, someone here said it looked like a 532 (?)

Just confirmed with previous owner that it has the 29 foot composit rotor.

Is that going to do the job? flown plenty of underpowered model airplanes (owned by others) that were barely able to fly, a real pain in the arse.

[MikeBoyette]

Spiff,
Get rid of those blades they are for a two place. If you fly that machine with those blades, you might as well stick a gun to your head and pull the trigger. That disk size is for a two place version of that gyro. Your disk loading will be to little. In 1989, at Bensen Day's, I witnessed a low time pilot in a 532 powered HTL Air Command PPO. As I have said before I was the first on seen and first to discover his body. He had bought the machine used and it had 29 ft Sky Wheels on it. He only had a few hours and thought he knew it all. He was told how dangerous this machine was to fly, and he dismissed it. He was flying in winds that most high time gyro pilots would not enjoy. He hit a gust, the nose went up, he shoved the stick forward. His daughter was right next to me when we both saw the gyro going in up-side down. An Air Command with HTL, with the right sized blades would be consdered dangerous, but one with 29' blades will be down right leathal. Do us all a favor and listen to experience. Get the CLT upgrade, and sell those blades. You should not need blades any longer than 25'. AND FOR GOD'S SAKE GET TRAINNING.

[spaceman spiff]

I assume blades longer than 25 feet will help me with the lift problem? Will 26 do the trick? i saw some wide blade versions advertized 8 and 8.5 in cords. Are they more suitable ?

[barnstorm2]

Ack! Except for winter it is 80 - 110 here most of the year. Presumably altitude is important too. I'm at 2200 - 2500 feet. Is that low enough that it will help me?

Not sure what engine i have, someone here said it looked like a 532 (?)

Just confirmed with previous owner that it has the 29 foot composit rotor.

Is that going to do the job? flown plenty of underpowered model airplanes (owned by others) that were barely able to fly, a real pain in the arse.

OOPS, Sorry, for some reason I thought you had a 447. 532 should be fine, though I have not flown one myself though, plenty here have.

It is still critical though that you get the CLT upgrade before going to Dragon Wings.

Lots of people still use the blades you have. If they are in servicable shape you could sell them to help make up for some of the cost of right-sized blades.

[cgmg]

Spiff,

You need to connect with Charlie Mara! He can explain all the questions you have about gyro flying in a manner that's easy to understand. It would be well worth your time to arrange a demo flight with Charlie, take the flight, and then get your questions answered by him. Please, though, let him know ahead of time you have a jillion questions for him, so he can make time for your discussion before or after your demo flight.

If you haven't ever flown in a gyro, you need some flight time anyway, to make sure you really want to spend the kind of money it will take to make your machine safe to fly. There are a lot of people out there who bought/built machines, and never got them off the ground after taking a few lessons. Personally, I think you'll love the demo flight, especially the landings!

It's good to be asking questions now, before you have a lot of money invested, but the next step should be a demo flight, and maybe a few lessons, before spending any real money on your machine.

[spaceman spiff]

Wise words Mr Mark.

He didn't call back yet, will give him a call this afternoon.

Thanks for your input guys.

[cgmg]

Spiff,

Don't give up on Charlie not calling you back. He's probably busy with students. Had the same callback problems during my training, but it always worked out that we eventually got together.

[Al_Hammer]

Spiff,
here are a few more details regarding HTL and why you should avoid it.
With HTL, any rotor unloading is bad because it leads to more unloading.
The more power you apply, the more the rotor thrust has to get in front of the cg to prevent a pushover. Now you've got a cocked trigger, because if anything causes that rotor thrust to move inward, such as pushing the stick to avoid a bird, or levelling off too fast at the top of a climb, the prop thrust will quickly tumble the machine forward.

Another problem: Having the rotor thrust vector way out front means that disturbances from gusts and thermals will be amplified, whereas in a stable gyro, the gyro tends to point into the gust, reducing the problem. The reason is that in a stable gyro, the rotor thrust is behgind the cg, not in front of it.

This same problem is at the root of PIO. A new pilot will often get into PIO in a HTL machine without adequate stab, because lack of weathervaning tendency causes the fuselage to lag behind the rotor when you make a stick input. (pull back, the rotor tilts, you climb, but the gyro stays level for a moment)The student then gets behind in trying to correct the attitude of the gyro and pulls the stick just when he should be pushing or doing nothing. After a couple of cyles of porpoising, the excursions become extreme and the gyro bunts over.
The rotor takes out the tail, usually and the blades often break soon after they stall.
As you mentioned, a CLT machine can get into zero g, too, but if it does, the danger is not as great. The rotor will lose speed due to unoading, but can tolerate a few seconds of this. What it won't do is instantly tumble as soon as the rotor is unloaded. In a HTL , unstabbed machine, of course, it may, if the throttle is open at the time.

Typical disc loading is 1.2 to 1.4. Below 1.2 the gyro will be more
sensitive to turbulence. But also you will have a slower turning rotor,
making it easier to reach critcal low RPM if "G" loading is reduced.
Also, with a real low disc loading, climbing at a steep angle with full
power, you could potentially dangerously unload and slow down your rotors.

Here is a rotor size chart for one brand of rotors.
http://www.skywheels.com/selection.html

[GyroRon]

[QUOTE=spaceman spiff]Keep in mind that i am a 225 pound guy in a gyro/engine reported to be a littel whimpy as far as power and lift capacity. QUOTE]

Not true at all Spiff. There was a fellow at Bensen Days named Bob who has a nice Aircommand about like yours but with the CLT kit installed. The only main difference was his engine was a Rotax 582 not a 532. Both engines have the same power, just the 582 has a smoother powerband and dual ignition, and a other improvements like a stronger crankshaft etc...

Anyway Bob is well over 6 foot tall and weights exactly 300 pounds!!!! His machine climbed out with him like a rocket ship.

I can assure you, you will have power to spare. I can also assure you that with that 532 engine you will have the power to buntover if you ever get into a mode of flight that would allow it.

Again, I think you need to do some TALKING to a very good instructor or gyro pilot and learn exactly what causes PIO and Buntovers. There is alot you should learn, and will learn if you stick with it.

Here is Bob and his gyro

[GyroRon]

I assume blades longer than 25 feet will help me with the lift problem? Will 26 do the trick? i saw some wide blade versions advertized 8 and 8.5 in cords. Are they more suitable ?

Spiff.... are you kidding me? I know you think I am a asshole, but man LISTEN to these people!

Disk loading is very important. Too high of a loading causes problems, too low of loading causes even worse problems. With your weight, and the weight of your gyro ready to fly, 25 foot blades would be the absolute Max length! Anything longer would be dangerous. If it were my gyro I would be looking for a set of 23 foot Dragon Wings. 29 foot blades are WAY WAY WAY too light of loading for your gyro.

I understand you shouldn't believe everything you read on the internet, but at least look at some of these posters profiles. Mike Boyette told you in no uncertain terms that 25 foot would be max. Mike Boyette is son of Ernie Boyette, Manufactor of the most popular blades on the market. Ernie and Mike have been involved with gyroplanes since before Mike was born. I think his dad started in the Early 70's. He grew up around gyroplanes. He knows what he is saying!!!

I am not trying to be a butthole to you, but it is a pain in the ass for us who are here to try to help others like yourself and you aren't listening. The CLT kit is a no brainer. There shouldn't even be a discussion on it, it is CHEAP LIFE INSURANCE!!!

I had a guy who flys fixed wing ultralights, who just bought his first plane and just soloed a month or two ago, what do I think about BRS parachutes, and do I think he should install one on his new plane.......... I told him it is really simple, The chute costs about 2500$ new and takes about a hour to install. He may never need it, but if he ever does and he does use it, then that 2500$ just saved his life. Then I asked him was his life worth 2500$???? He said the chute would be on order tomorrow. Simple as that.

If you got 29 foot blades and they aren't all cracked and chipped up, they are worth big bucks. You can sell them for enough to easily buy a new set of blades and shipping.

[Chuck Roberg]

Spiff, your not that far away from Phoenix. Why not give the Sportcopter guys at Buckeye, AZ a call and set up a demo flight.

You'll be able to feel how a C/L thrust gyro should fly. Terry or Steve will be able to explain the differences to you.

Plus you'll have a ball flying it.

Oop's correction to above. As Ron mentioned, it should be SparrowHawk not Sportcopter in Phoenix. I had one of those brain farts when typing. :eek:

[GyroRon]

Sportcopter guys in AZ? Maybe you meant to say Sparrowhawk???

[spaceman spiff]

" Anyway Bob is well over 6 foot tall and weights exactly 300 pounds!!!! His machine climbed out with him like a rocket ship. "

Yea Baby!

" I can assure you, you will have power to spare. I can also assure you that with that 532 engine you will have the power to buntover if you ever get into a mode of flight that would allow it. "

If i have lots of power and a big moment between CG and thrust line, i agree, it is going to try to pitch the frame somewhat during acceleration. No question about it. No getting around newtonian physics. I just don't see the type of crash you are describing in the reports.

Someone could try to convince you that you need a special parachute for your car in case you slide off a road and fall off a cliff. Happens once in a while, and people can show you the numbers, post eye witness accounts of how horribly mangled the bodies were, tell the tearfull tale of how the victim left a beutiful widow and 3 perfect kids... but ultimately you have to make a decision whether to get the parachute or not. Do you base that decision on how horrbly mangled the guy was? Or on how moving the story of his perfect family? How helpless the guy was once he slid off the road?

I will know a lot more once i have had my first few flights with an instructor, but for now all i have to measure the weight of what you are saying is what i can or can't see in crash reports. The picture may be very different after i fly some. Anyway there are some very good arguments based on efficiency and smoother handling of a CLT that have my attention. probably will get one.

Thanks, and best regards.

Joe

[spaceman spiff]

_____________________________________________
Spiff.... are you kidding me? I know you think I am a asshole, but man LISTEN to these people!

Disk loading is very important. Too high of a loading causes problems, too low of loading causes even worse problems. With your weight, and the weight of your gyro ready to fly, 25 foot blades would be the absolute Max length! Anything longer would be dangerous. If it were my gyro I would be looking for a set of 23 foot Dragon Wings. 29 foot blades are WAY WAY WAY too light of loading for your gyro.
_____________________________________________

I don't think you are an asshole. But keep trying ;)

I am listening, just not running to a conclusion as fast as you would like. relax, plenty of time before i plumet from the sky to a firey grave.

The 26 foot was just a question based on the idea i had little power and limited lift, if it is not a problem great. if i don't ask i don't create an oportunity to learn. no reason to get your panties in a bunch over it. ;)

thanks for the dragon wings recomendation. I'll have a look.

[aerodynamicdon]

I'm sorry to have you recall bad memories, but this was both interesting and horrible. How did your friend get hit by an RC plane? Was he hit from behind by someone else? I used to fly Sig Kadets that floated like butterflys with lots of time to get out of the way. e mail or thread. Take care,
Don Lee

[spaceman spiff]

WOW! Great post Al Hammer.

First paragraph understood, I'm back on board with the CLT kit.

I got stuck on the second paragraph on rotor thrust vector out front? if it is a lengthy or awkward to explain its OK not to, but very interested in what this is, so i can make sense of the rest of that paragraph.

Loading range, well explained, will shoot for 1.3 to 1.4.

thanks for the rotor sizing link, answered almost all my qestions save one: Cord, any advantage in the wider cords being offered? 8, 8.5?

Many thanks
Joe

[GyroRon]

Look I won't bother you about anymore for a while. But instead of looking at accident reports - since I am sure you still don't understand what they really show yet - How about taking a minute to look at the current crop of gyroplanes on the market right now. Especially the newest models.

Dominator - CLT

Butterfly - CLT

Monarch - CLT

New Aircommands, all of them - CLT

Sparrowhawk - CLT

KB-2 - CLT

Gyrobee - Nearly CLT

Magni - Nearly CLT



Look at the fact that a whole new gyro company came about - AAI, who makes the Sparrowhawk - by a designers desire to transform the RAF2000 gyroplane from a extreme HTL machine to a CLT machine. Their retro kit they designed and sold caught so much positive attention that they came out with their own complete gyro kit and they have dealers and new gyroplane instructors popping up all over the USA. They are the number 1 selling gyro on the market right now.

Overseas as well the trend is going to CLT. The Futura is a gyro I personally would pay big bucks for and it is CLT.

All I am saying is instead of looking a accident reports, ask yourself why would manufactors build CLT gyros over HTL machines? Why would most people in the market for a new gyro demand a CLT machine? I mean really think about the facts and ask yourself, if CLT is not needed or is just a bunch of fluff, then why would Aircommand come out with a kit to convert the older machines? Why is their current line up of new models all CLT?

Good luck with your decisions.

[spaceman spiff]

A/D/Don,

My friend got hit by a plane i had sold him a couple weeks before. He flew it into the sun and lost sight of it. it was turning at the time. He didn't power down, or yell, the plane ended up on a path heading right for him and he couldn't see it. Hit him in the chest, it was bad, real bad.

We have an annual fun fly named after him. comming up in a couple weeks. Geeze, he was a neat guy. last time i talked to him he had run up beside me to give me a hand with some boards i was carrying...

[Al_Hammer]

WOW! Great post Al Hammer.

First paragraph understood, I'm back on board with the CLT kit.

I got stuck on the second paragraph on rotor thrust vector out front? if it is a lengthy or awkward to explain its OK not to, but very interested in what this is, so i can make sense of the rest of that paragraph.

Hey, thanks Spaceman. I see you are an engineer.
The rotor thrust vector, which is a line perpendicular to the rotor plane, if you aren't familiar- is the only way to control the gyro. Wherever you point it with the stick, that controls pitch and roll by moving the lift line(RTV) off of the cg.
Trouble is, if the prop thrust is offset from the cg(HTL) then the rotor thrust need to point so that it passes in front of the cg so its lifting the nose while the prop is trying to lower it, to maintain balance of pitch moments.
It has been found that a stable gyro is set up so the RTV(rotor thrust vector) passes behind the cg and the stab will then have to have a downforce. This config tends to pitch the gyro into the wind in a gust or g load disturbance.
I've heard that wide chord blades shake a lot, so they aren't used much, if at all on gyros, as far as I know. Ernie , (of Dominator)experimented with them on 2 place gyros, but never sold them, possibly due to problems.

[Udi]

Joe - you are getting a lot of good advice here, but I will add some of my own experience.

1. First, have an experienced gyro builder look over your gyro to make sure rebuilding is even a good idea. I rebuilt an old Air Command and regretted many time I even started. Yes, I ended up having a safe flying CLT gyro, but the work time and money I put into it was not worth it. Some old gyros belong in the dumpster. Remember that aluminum tubes are not very expensive. If everything other than the tubes is shot, you may be better off building a new gyro from scratch.

2. If you decide this gyro is worth salvaging, don't cut any corners. The engine has to be airworthy. Install the CLT upgrade and the stabs. Replace the mast because your mast is a single tube and is drilled thru the wrong places (get a 72” mast). Turn the engine right side up. You will need a new pre-rotator shaft anyways because the old one will be too short after you turn the engine right side up. Replace ALL the bearings. Your gyro was sitting in the rain and the bearings are shot. Ron was right - send the rotor head to A/C for rebuilding. I think you may also have to replace all the plastic saddles - and there are many of them. The saddles on my gyro broke in my hand as soon as I took the tubes apart. This is a big job, Joe.

3. I ran the numbers on the HP3 spreadsheet, and I think you will be better off with 25 ft DW rotor blades. Your all up weight will be about 650 lbs and you are flying at a high DA. 25 ft blades will give you adequate lift. But don't let skinny guys like me fly your gyro because the blade loading will be way too low for them!

I hope this helps.

Udi

[spaceman spiff]

The rotor thrust vector, which is a line perpendicular to the rotor plane, if you aren't familiar- is the only way to control the gyro. Wherever you point it with the stick, that controls pitch and roll by moving the lift line(RTV) off of the cg.

Trouble is, if the prop thrust is offset from the cg(HTL) then the rotor thrust need to point so that it passes in front of the cg so its lifting the nose while the prop is trying to lower it, to maintain balance of pitch moments.

It has been found that a stable gyro is set up so the RTV(rotor thrust vector) passes behind the cg and the stab will then have to have a downforce. This config tends to pitch the gyro into the wind in a gust or g load disturbance.

.

OK, took me about 50 times thru, but i think i got it. The first and last section i accept. The middle one not sure.

If you are flying steady state, i would think the center of drag would be the important thing. If for example if you substituted the wheels for ones that were unussually large, but same mass, the drag from them would create a pitching forward and you are back to sqaure 1, because the disk would have to pivot back to compensate. even thoug there is no change in CG

in the case of the CLT conversion you are moving the drag of the pilot upward so you end up with less pitching forward due to drag, so you end up with less copmpensation needed from the disk.

Same conclusion, just different reason.

If you agree, do i get a passing grade for Gyro 101?

[Al_Hammer]

Yes, the center of drag must be taken in to account, too. All the forces of thrust and drag and their moment arms need to be summed together. The aircraft will pitch and roll about its cg, as a result of the vector sum of all of these forces.
Adding drag down low with big wheels will have an effect, no doubt.
Raising the pilot higher raises the drag center, but it also raises the cg and puts it closer to the prop thrust line. Same with turning the gearbox so its down instead of up. This is more important than drag center because the prop thrust is hundreds of pounds and when the moment arm gets too long from a high thrust offset, the pitching moment is so large that it dwarfs other forces, especially at low speed, high power. Once the thrustline is close to the cg, then the rotor thrust will likely be able to pass close to the cg without needing to make big alterations in drag profile.
If you followed the other points, then you are heading towards an A on this test for sure.

[spaceman spiff]

UdI,

Yup every time i come to the board its annother thing i need. looks like at least 2000$ more today than it did yesterday. So long as the engine isn't toasted i should do OK.

Does that program show what load/footSq the 25 footers come out to?

[Udi]

UdI,

Yup every time i come to the board its annother thing i need. looks like at least 2000$ more today than it did yesterday. So long as the engine isn't toasted i should do OK.

Does that program show what load/footSq the 25 footers come out to?
Yes - 1.3 lb/sqft. The 26 footers will get you down to 1.2 - still reasonable. But with the AZ thermals I think you will be better off with 25 ft.

Udi

[spaceman spiff]

So 26 foot is reasonable? hmmm (rubbing chin) He he..

Hey Ron! :p

:D :D (just messing, 25 or 24 still sounds like the ones for me)