Pitbull

[DBerke]

I am new to Gyro flying, only about five hours of training :) . I am about 95% of the way done with a Gyrobee and plan to use it to get some hours in once I am ready to solo.

I am starting to think about a second machine and kind of like the look of the Pitbull. Maybe this can help me get past the WI winter. Well, my question. Are there any flying Pitbulls in the WI, MN area that I could look at or others that I could get some input from?

Thanks

[Udi]

The Pitbull sure looks nice, but I have yet to see a satisfied owner...

Udi

[Mike Jackson]

Hi Dennis,

I don't know much about those who have flown the PB. The video John VanVoorhees puts out is quite good. The machine looks quite maneuverable. Don't let rumor and inuendo decide for you. Give John a call. He's a super guy and has sold this machine all over the world. You'll find more of these machines left of the Rockies.

Construction is relatively simple - one long 2x3 keel ending with an engine mount and a 2x3 mast surrounded by the pod. Engines range from a 503 to a Subaru. A friend of mine near Tucson is building one with a BMW 1150R motorcycle with redrive (built in England). Nice 4 banger, good horses and apparently very popular in Europe with the sport plane crowd.

A fairly nice web site might give you a reasonable idea of the construction - a member of the Colorado Chapter 7 of the PRA. The address is:

http://www.milehighgyroplanes.com

Why isn't it more popular? I'm not sure. The taildragger configuration scares some people. Some don't like the landing gear wire bracing which stiffens the gear in lieu of drag and compression struts - but it's lighter. Some don't like the rudder bar instead of rudder pedals. Others are not fond the gas tank by your feet. The web site will show this.

I'm 6' and 220# and was not sure how I'd fit. There is plenty of room inside the fiberglass shell. I found it quite comfortable.

I'll try to attach the PB here with the BMW engine. I haven't been too successful with getting pics on this site but I am digitally challenged.

Hope this helps. BTW, if the pic does not come thru I can send it to your personal email.

Well horse s@*t, I get a "page cannot be found" and Unknown Error -1 on the upload attempt. I found it, but the computer can't - imagine that.

Send me your email address.

Cheers,

Mike

[flyawayhome]

I tried to get more info on the Pitbull but was a little dissapointed. Called twice, got answering machine & never returned my calls. Tried e-mailing and the address was no good. The website appears to be totally outdated w/ the information listed on the PRA mfg. section. The PRA site lists an "ultralight" a single place, and a two place. North American Rotorwerks (Pitbull) website shows only the single place with completely different prices and performance specs. than the PRA. Until I talk to more than one Pitbull owner/builder/flyer I'm stayin real clear. They may have a great product, but their Marketing needs help, bigtime. Thom

[Mike Jackson]

Hi Thom,

By his own admission, John VanVoorhees, is not a great marketeer. He is more of a hands on builder and is "a force of one". Unfortunately, not unlike a lot of "manufacturers" today.

His first website is very outdated. I stumbled across a more up to date one:

http://www.pitbullgyroplanes.com

I've found I can get him on the phone 1 out of 4 trys, typically. Very friendly and loves to talk gyroplanes.

Cheers,

Mike

[chuter]

DBerke,

Be sure you talk to some of the satisfied owners, they sure don't post here. :(

[flyawayhome]

Mike, You mentioned your friend bulding a PB in Tuscon. I'd like to see it. Tucson is about 2 hrs. south. Thanks, Thom

[Udi]

... Don't let rumor and innuendo decide for you. Give John a call. He's a super guy and has sold this machine all over the world. You'll find more of these machines left of the Rockies...

All we need is ONE person who knows someone who likes their Pitbull. There are no rumors and innuendo - rather, there is lack of information regarding successfully flying Pitbulls.

Mike, the gyroplane fraternity is fairly small. Don't you think that if there were a nice flying Pitbull someone would have seen it? Buying a kit gyroplane without a first hand knowledge of other happy customers is a foolish thing to do. Next time you talk with the Pitbull manufacturer, why don't you ask for a list of refernces?

The link you have posted above for the guy in Colorado is a perfect example of the fate Pitbull builders. They build them and then they sell them – un-flown! What's the deal with that?

Udi

[DBerke]

Mike

Looks like you have emails blocked from the forum so I can not send you my email. I do not have my email blocked. You can send me an email by just clicking on my name in my post. Like to get any information I can.


Dennis




Hi Dennis,

I don't know much about those who have flown the PB. The video John VanVoorhees puts out is quite good. The machine looks quite maneuverable. Don't let rumor and inuendo decide for you. Give John a call. He's a super guy and has sold this machine all over the world. You'll find more of these machines left of the Rockies.

Construction is relatively simple - one long 2x3 keel ending with an engine mount and a 2x3 mast surrounded by the pod. Engines range from a 503 to a Subaru. A friend of mine near Tucson is building one with a BMW 1150R motorcycle with redrive (built in England). Nice 4 banger, good horses and apparently very popular in Europe with the sport plane crowd.

A fairly nice web site might give you a reasonable idea of the construction - a member of the Colorado Chapter 7 of the PRA. The address is:

http://www.milehighgyroplanes.com

Why isn't it more popular? I'm not sure. The taildragger configuration scares some people. Some don't like the landing gear wire bracing which stiffens the gear in lieu of drag and compression struts - but it's lighter. Some don't like the rudder bar instead of rudder pedals. Others are not fond the gas tank by your feet. The web site will show this.

I'm 6' and 220# and was not sure how I'd fit. There is plenty of room inside the fiberglass shell. I found it quite comfortable.

I'll try to attach the PB here with the BMW engine. I haven't been too successful with getting pics on this site but I am digitally challenged.

Hope this helps. BTW, if the pic does not come thru I can send it to your personal email.

Well horse s@*t, I get a "page cannot be found" and Unknown Error -1 on the upload attempt. I found it, but the computer can't - imagine that.

Send me your email address.

Cheers,

Mike

[Mike Jackson]

Udi,

You're absolutely correct regarding references. I am also seeking info myself. I wasn't aware the builder in CO sold his? Do you know why?

There was an individual, Tim Wells, I believe, who built a beautiful machine. He won one or more static awards for workmanship only to sell it before he flew it. The reason I heard from John V. was he couldn't find adequate tng. I'm not sure who bought his machine.

Sorry I can't give more names, but over the years I have seen pics in the PRA rag of PBs at ElMirage. I'm anxious to see how Charlie Mara's (AZ) PB with the BMW engine turns out. Charlie is a well respected gyro instructor originally from IL and part of the STL Chapter of the PRA. I'll try to get him to post a flight report in the Forum or maybe an article for the PRA magazine.

I understand a builder/buyers concerns regarding safety and quality of a project. Not too many want to "go where no human has gone before"i.e., not the first in line. References are important. I might suggest archiving pilot reports in the forum. Maybe a seperate topic heading for each design type or possibly a subheading for each design type already having a Forum topic.

Qualitative pilot report inputs should try to include semi structured guidelines for topics of interest rather than just "it flew real good". The more reports for any given model the better. I just believe there are large untapped sources for inputs, both contractor and consumer, which might be solicited. A good example of a limited flight report was by Rusty Nance regarding the ELT conversion on the SS Air Command. Succinct, to the point discussing high and low speed handling and maneuverability. It was on AC's old website. Their current one looks incomplete to me as yet.

Cheers,

Mike

[Udi]

...I wasn't aware the builder in CO sold his? Do you know why?...

Click on the link to his web page. I don't think he sold it yet.

Udi-

[GyroRon]

I had a chance to fly one last year at ROC. It was powered by a subaru EA-81 with a Rotax C type gearbox and a three blade prop. It never could get enough power or speed or whatever to get airborne. The engine kept overheating stopping me from being more aggressive on my attempts. And it is fair to say I may not have done my takeoff attempts right for a Tractor gyro - I pre rotated and went to full back stick and slowly built up speed till the rotors were up to speed, then allowed the stick to go forwards some to allow even more speed to build up, but even at what seemed like enough speed to takeoff it never would. Maybe I should have given it even more forwards stick and got even more airspeed built up???..... Maybe if the owner still has it and has the engine troubles fixed and has it at ROC I will try to fly it again.

[jucie]

What? Did somebody manage to build something Ron Awad isn't able to fly? :eek: Quite an achievement! :p

[Rotorhead]

Hi everyone

I am also going to abandoned Guide wire cables, beefing up control stick
Assembly and upgrading to pedals, mine also has the glass laid up very thin
( lighter the better ) but I will add glass ribs to make it more kid ( adult )
proof

Flying Picture & thoughts below from a somewhat satisfied customer

The 503 is an excellent power source for the Pitbull. With the reduction
gear you can use props of over 68" in length that translates into massive
torque and more then adequate power. But there are many other difficult
obstacles that must be over come with the Pitbull.. The greatest being the
support cables for the main gear.

There are very many positive things ot be said about the pitbull. The
tractor design has so very many advantages over the pusher. I do not feel
it is too short at all. The longitudinal stability is very good and
the surface area combined with the dihedral create a huge air dam in the
nose down configuration making a power push over almost impossible. The
lateral stability is another problem especially for a beginner pilot.

The biggest problem is that there are no tractor trainer gyros available
yet. So I was forced to Transition from a tricycle gear pusher, flight test
the pitbull and solo all at the same time. This was quite overwhelming.

What do you have for a tail wheel now? I had build a steerable tail wheel
with a locking indent for mine. The tail dragger configuration is very
prone to ground looping. I had ground looped on 3 occasions. The fixed
tail wheel helps prevent this. The down side is there is not enough rudder
authority or good ground control with a fixed tail wheel. So many people
have gone to steering brakes on the mains.

Do you plan on flying this as an ultralight?

I had used over sized cable and double crimped and even triple crimped many
of the cables. Yet the support cable still pulled through the eye. The
reason for this is where the support cable is mounted on the main gear
is 1/3 the distance from the pivot point on the main gear. This has created
an over shot lever. for every pound of back pressure placed on the main
gear there is 3 times that put on the support cable. The best fix I have
seen was done by a gentleman in Holland. He replaced his cables with solid
tubes. Still the ultimate fix would be to throw away the cable and main
gear and build the mains in an A-frame style similar to a piper cub.

.

Please take care,


Anyone know how to contact the guy in Holland ?

[DBerke]

This has me kind of concerned. I did talk to John and he does seem like a nice guy. Loves to talk about Gyro's for sure. I think he said over 30 are out in the field! But still no one has said they are flying and have no issues. Well I may just have to dust off my CAD and mechanical engineering books and put together a tractor design of my own. The rudder issues and wire on the landing gear do not sound too good.


Dennis

[flyawayhome]

Dennis, I believe an an affordable ultralight "tractor" would be well recieved in the gyro community. I'm not an engineer, sounds like you may be. Check out
http://affordaplane.com Instead of starting from scratch, could one (perhaps) use this design as a base for a gyro? Thom

[Mike Jackson]

Hi Dennis,

Sorry it took me so long to get back regarding to the Tucson PB. His name is Charlie Mara. His email is

flyingms@msn.com

He's a great guy and an excellent instructor. Nice progress on the Pitbull too. It would give you an opportunity to sit in one and discuss the changes he's making.

Cheers,

Mike

[GyroRon]

I think a good base would be the Team Airbike. It would be alot like a pusher gyro but with some of the tractor gyros advantages.

[Airone]

John V. will be hard to get a hold for awhile, He is taking care of his Dad he had triple bi-past surgery a couple weeks ago.

Jon

[Brent_Brown]

Ron I think your are right about the airbike. I saw a tri-bike and I think it would be better to covert, but I can't find anything about it now. Can someone tell me what happened to this plane.

[Brian Jackson]

Ron I think your are right about the airbike. I saw a tri-bike and I think it would be better to covert, but I can't find anything about it now. Can someone tell me what happened to this plane.
Brent,
I used to design & manufacture full-scale mylar builder's templates for Ison Aircraft, back when they were known as TEAM Aircraft. Recently, Wayne Ison sold off the assets and rights to the company which is now owned and operated by JDT Mini-Max (http://www.jdtmini-max.com/). Their site is currently under development, but check back soon. You can get the whole scoop in the UltraFlight Radio interview HERE (http://www.ultraflightradio.com/archives2004/archives0405.html). It's the first segment in the May 25, 2004 archive.

Of further note, Lowell Farrand has a vested interest in the new ownership. He's a good friend whom lives not far from me. Search his name in UltraFlight Radio and you'll see why this is relevant to the continuation of the MAX line of aircraft, of which the AirBike is among.

Cheers,
Brian Jackson

[Kevin_Richey]

Lowell Farrand has a vested interest in the new ownership. He's a good friend whom lives not far from me. Search his name in UltraFlight Radio and you'll see why this is relevant to the continuation of the MAX line of aircraft, of which the AirBike is among.

Cheers,
Brian Jackson

Lowell Farrand is an old-time gyro pilot that was the first test pilot of a powered parachute canopy attached to a gyro several decades ago in Indiana, according to an Ultraflight magazine article a few years back.

[Brian Jackson]

That's the guy. He also has a long history with Wayne Ison, and was instrumental in many of the early Ison designs like the PDQ. Lowell was one of the first dealers for TEAM aircraft, and the guy I bought my MiniMax kit from. So to have Lowell & gang as active investors with JDT Mini Max is kinda like "keeping it in the family" so to speak.

[Brent_Brown]

I have been to the JDT web site and emailed them but no repley.

That nose gear looks to long like it would get hit by the prop.

[Brian Jackson]

I have been to the JDT web site and emailed them but no repley.

That nose gear looks to long like it would get hit by the prop.
I thought it looked a little different than I remembered it... This site (http://www.ultralightflyer.com/airbike/) shows the configuration as a taildragger.

[Airone]

Hey Guy's
Im looking for anyone that made a set of plan's off of the Pitbull Gyroplane,
and if so are you willing to sell them or make a copy.

Jon P. Gardner
Bend, Oregon

[jsligar1]

I have the PB that Ken wells built. Ron did try to fly it at ROC 2003, but as he said was under powered. I made the following changes and Ron flew it this year at ROC and I'm sure he would tell you about it if ask. I have been flying it down the runway,
but have not went around the pattern. It is me not the plane. I am not familar with a tail dragger. I have not had any trouble with the cables.

The changes I made for this year were: Took the body off
Went to a Hirt G-40 redrive 2.03x1
70" Power Fin prop
Full radiator instead of one that was cut up
Took baffels out of exhaust pipes

I am in the process of putting the body back on now.
If you look up ROC 2004 you will see it.

I do not have any trouble getting in contact with John. His number is 206-763-9392.

Fly Safe
John

[thesultanofscud]

What happened to the Van Voorhees Pitbull on floats? I saw a picture of a capsized tractor gyro on floats on another thread...that wasn't the Van Voorhees Pitbull on floats was it?

I always wondered how that thing handled and performed...any incite?

[John Stahl]

The thing that scared most builders was the pitbulls tendency to ground loop.
I now own a pit bull and am wondering what can I do to prevent it from ground looping.
I have increased the HP to 120 horses. Added a prerotator. I feel that one of the problems is in takeoff procedures. I think there may be too much forward stick given and the tail comes up first instead of the mains. Am I on the right track?

[karlbamforth]

The thing with fixed wing taildraggers is that when you lift the tail, gyroscopic progession on the prop causes the nose to swing left/right depending upon prop rotation, this can require a lot of rudder to keep straight.

I have never flown a tail dragger gyro, but it looks as if the same thing might happen to the main rotor.

It would appear that it could be possible to have a combination of roll and yaw induced when you raise the tail, at low airspeed or with a small rudder you may have limited directional control.

Please remember I have never flown a tail dragger gyro so take anything with a pinch of salt.

With the above in mind it might be best to leave the tail down and lift off in a 3 point attitude.

This is all just me brainstorming aloud. Hopefully someone who has flown one will be able to add more.

[chuter]

From my experience with my taildragger gyro I'd say what Ranger said is at least part of what goes on in the take off.

Another thing I've discovered; if you have the mains on the ground and the rotor tilted to one side it tends to pull the tail around in the direction the rotor is tilted.

Keeping the tailwheel on the ground and lifting off 3-point is easier to keep straight but you can end up pretty far behind the power curve that way, just like a soft field take off, so you need to lower the nose and gain some airspeed so if the engine quits you'll have enough airspeed to flair.

You've just got to keep your happy feet loose and ready to correct.

I've heard that Pitt Bulls came with a non-steering tailwheel; if that's true it could be a real problem in a lot of ways.

[John Stahl]

my Pitbull has a stearable tail wheel but Dusty would lock it for take off. that may have been a problem. May be he needed to wate tell after take off to lock the wheel

[Airone]

John
Did a copy of the Pitbull manual come with your new toy?
I think I have another copy of it or I can burn a copy to CD if you need one.

[John Stahl]

I have a copy of the manual.
I may change the gear to a tricycle configuration.
I looked at it today and it wouldn’t be that hard.

[garybuster]

Hey Jon and/ or John...

can either of you take a moment and send me a copy of the plans... I've received a kit, but since it is multihand downline from the manufacturer, I don't have a parts list, or assembly manual....

any efforts of yours to get me a copy would be most appreciated!!

Thanks ahead of time for your efforts!!


Gary Buster
tyler Texas

garybuster@hotmail.com
fax 206 424-4701

[Airone]

Goodmorning Gary

I can send you a copy of the parts list and assembly manual.
Would you like it on paper or CD?
You can email me at windstar_aviation@yahoo.com with your address.

[Jean Claude]

I often read that the tractor has a tendency to loop of ground because the center of gravity is behind the main wheels. If you put much weight behind, it is even more unstable. but we accept that the main wheels are those who bear the greatest weight, when you put much weight behind, is the rear wheel which becomes Main. And center of gravity is in front of the main wheel. This is contradictory! So i do not accept this reason. In my opinion it is the lack of authority of the rear wheel that is the cause

[magilla]

Jean Claude - think about it...you have a pivot point(the gear) and the center of gravity. If you are traveling forward, the natural tendencey is for the cg to lead. Go around a turn with CG behind pivot point, and it will swap ends.

The key to designing a taildragger gyro is the same as that for a taildragger FW - you put the mains just forward of the CG so that the acft doesn't tip when you get out of it.

[Jean Claude]

Magilla
You are right only if the rear wheel is lifted or if it moves freely, but not if it is directed firmly. If it is firmly directed you can not ignore it simply because it is small. In this case where is the gear? before? behind?
With great authority on the rear wheel, there will be no loop if the front wheels are soft. For in this case the drift of the front wheels is greater than the drift of the rear wheels.
The condition of stability is just there. Not in the position of the wheels "main"
And you can still increase the drift of the front wheels through an angle of opening.

[bowns]

But,Jean Claude,your tail wheel won't be the 'main' since the CG can't be far from center of lift as I understand it. In your tail wheel being main gear case, wouldn't we get a tail heavy plane or a single wheel maingear under her belly?I could be wrong but it just sounds odd to me.Can you put some more words on it,please.Thank you.

[Jean Claude]

I just want to explain the reasoning wheel main / wheel auxiliary us away from the cause of the loop tail. What is important is the ratio of autority front wheel / rear wheel. A free wheel has no authority and very little with springs. A wheel rigidly held has great authority. If the front wheel is rigid, the ratio authority of front / authority rear >1 gives instability. Also, no rear wheel free, otherwise loop. For a tractor, you need a steerable rear wheel but inflexible (no déport axis), and also reduce the authority of the front wheels (tire inflated balloon low). Thus the ratio of front / rear becomes <1 and the loop of tail is overcome

[WHY]

I believe what Jean Claude is pointing out here is the same reason that most WW11 fighters (taildraggers) and large trainers had a tail wheel that could be locked in position for take-off or unlocked for ground handling, one should keep in mind that even a "flexable" fuselage at the rear can give the same effect a a free tail wheel, in a word, if the tailwheel is free or the fuselage is flexable during take off you stand a good chance of seeing where you have been VERY QUICK.

Tony

[Jean Claude]

I insist heavily because it is a pity to abandon the tractor just because of poor design of the rear wheel. To have the authority, the rear wheel must be enough heavy on the ground ( the opposite is done usually). But simultaneously we must give high precision guidance. No centre shifted behind the pivot(it is the opposite is done usually). To avoid the shimmy, you need to attach everything to a rigid tail difficult to twist (Not the tube of small diameter used usually ).

[Not Yet]

Jean Claude

It is obvious that you have never driving a forklift truck or you would know that even with the very strong steering wheels, it wants to swap ends in a hurry.

[karlbamforth]

David,

I think you missed Jean's point. Maybe the language problem.

Basically (from what I understand) he is saying if the tail is light or has a low break out force for steering (low authority) then it will try to switch ends.

Because in a tail dragger gyro we want to T/O and land in the three point attitude or even tail low then we should and can put more weight on the tail (High authority) this will help to increase the grip and stop the tailwheel skipping sideways when we don't want it to.

I think the yaw and ground loop problems ppl are having with tail dragger gyro's is more of a technique issue. I suspect most have tried to copy fixed wing technique which I am starting to believe is wrong.

[Jean Claude]

Thank you Karl
My son had a small plane biplane in tandem (MIGNET HM293) heavy tails, and tendency of the loop tail. After installing rear wheel locked and provided an opening angle of the front wheels, now it is stable. Taxiiing with differentials brakes.
David, i have never driving a forklift truck. But it will always be unstable because the front wheels are more rigid (authority) than the rear wheels.

[Not Yet]

Ranger

It makes no difference whether or not the tail wheel has high or low authority, when the center of gravity is behind the main gear, there is a strong tendency to over steer.

[karlbamforth]

You are quite correct David but what Francois is getting at is that if the tail wheel is free to rotate or with little weight on it so it can skip sideways, it will oversteer easily.

If the tailwheel is locked or has a high breakout force with weight to make it grip the runway surface it will not over steer so easily.

I am much better at explaining things face to face. LOL

If the tailwheel is light so that it has low grip and can skid sideways or casters it can easily over steer.

If it is locked and (relatively) heavy it will have a lot of grip and resist sideways movement.

He has also pointed out that if the maingear has toe out it will also resist swapping ends.

[John Stahl]

I am beginning to believe that rotor management is much more critical with tail draggers that trikes.

If you do not have rotor perfectly level the rotor will pull you to the side.
I think keeping more back stick and keeping the wheel on the ground is important.

I know we will be taking off behind the curve so once we get in the air we need to stay low tell we catch up with the curve.

[Joe_Terminella]

Hi Folks .
I have not flown a tractor taildragger but I have built my own design and taxied for many hours. A guy named Ron Herron who has been around for a long time has already done the hard work for us. If you are interested in tractors ........buy his plans and study them. The tractor does not have any tendencies to ground loop when designed properly. Unlike a taildragger airplane , the ground speed is relatively low.......once you bring on the power the rudder takes over from the wheel and when designed properly it is very controllable. I would not be afraid of the taildragger...........however, you can not expect to hop in and fly away without training. I have over 300 hours in Bensens design and another 300 hours in Taylorcraft F-22 taildragger.
So ........what I am saying is get trained and fly your taildraggers without much problem of ground looping.