Building Mariah Gale

Vance

Gyroplane CFI
Staff member
Joined
Oct 30, 2003
Messages
18,363
Location
Santa Maria, California
Aircraft
Givens Predator
Total Flight Time
2600+ in rotorcraft
This is the beginning of the build thread and a way to answer the question why.

She is called Mariah Gale because Mike and Golf are the two single syllable letters in the aviation phonetic alphabet. This makes it very easy to say on the radio. The Predator is 142 Mike Golf. I reserved 26MG for an N number for the aircraft I want to build. The streamliner I crashed was called Mariah after a song about a wind that blew my love to me. It seemed appropriate for an aircraft that is going to carry my love and me across the country. I asked Ed to come up with a G name for her that had to do with the wind and she picked Gale.

The engine and propeller change on the Predator went so well I imagine I am a brilliant gyroplane designer. I would like to build a faster, longer range, off airport version of the Predator.

I would also like to mitigate the things I don’t like about the Predator. They are minor things but I feel they can be better.

I feel that Mark did a great job designing the Predator and I am going to use a lot of his ideas. The layout is going to be very similar because each time I try something very different I see why Mark did it that way and realize that is a very good way to do it. There is also less engineering risk in replicating a proven design. I can’t afford to go through multiple iterations to get it to work well.

In short this is basically a copy of Mark Givans’ design. It is a two place tandem with a fairing, no top and a cowl over the engine.

The primary goal is to reduce the coefficient of drag times the frontal area by 30%. This will be done with both a small reduction in size and improving the way she goes through the air. The dune buggy tanks account for almost two square feet of frontal area and the suspension another two square feet. It is an easy area to improve.

The way the windshield ends on the Predator is not the best for low drag. I feel it is better if you let go of the air with the shape converging. I would like for Ed to have her own windshield.

I feel that an engine cowl would reduce drag and improve cooling.

A secondary consideration is to reduce weight. I hope to remove some weight from the body and a little from the chassis. This will be more than balanced with additional fuel for a longer range and a heaver empennage.

I feel that a longer range is important to have a carefree wandering across the United States.

I am going to use the same IO-320 B1A engine and three blade Catto propeller as the Predator. There may be a certain amount of re-pitching the propeller for the hoped for higher top speed and higher cruising speed.

At this point in time the frame is similar to the Predator only made from 4130 instead of mild steel. The Pratt Truss will be very similar except the rotor tower will be rubber mounted. The two 25 gallon fuel tanks will be inside the body. The legs, tail boom and rotor tower will all be faired and all exposed tubing will be either airfoil shaped or faired.

Instead of a tube and fabric empennage I am going to bolt on a complete Mooney empennage. The vertical stabilizer will not be braced at the top and the horizontal stabilizer will be shortened to 6 feet. The elevators will be used for pitch trim in flight.

I expect to have 12 inches of main suspension travel with very little tire scrub. The front which is rigid on the predator should have about 6 inches of travel and a 5 inch nose wheel instead of the Predator's 4 inches. This is to improve the aircrafts ability to handle an inelegant landing and takeoff from off airport. I will still use differential braking for steering.

I also want to go with a hydraulic pre-rotator so I can hear the radio when I am pre-rotating. I want to drive the pump from the Lycoming accessory case and use a bypass for engagement.

I would like a radio with the ability to monitor two frequencies at once and a transponder.

I am hoping to manage the rotor control linkage in a way that minimizes stick shake.

I would like a place to carry at least two cubic feet of luggage.

When I was on this last trip I purchased an engine mount for the IO-320 B1A that will define the main chassis and a Mooney empennage.

I purchased a “register an experimental aircraft kit” from the EAA.

I also purchased a 3 1/8” JPI EDM 4 C with fuel flow, oil temperature, oil pressure, volts, four channel cylinder head temperature and four channel exhaust temperature.

She is going to have steam gages for engine rpm, rotor rpm, vertical speed, altimeter, airspeed indicator and a vertical card compass.

I expect to use an AvMap portable GPS with terrain once she flies.

I expect this build process to take more than a year and I will have the Predator down as little as possible during the build. I would like to find a core IO-320 B1A so that I don’t have to remove the engine from the Predator until Mariah Gale is ready to fly.

I hope to pay a friend of mine who makes motorcycle seats to make the body from Kevlar and carbon fiber. He made the body for my Streamliner out of Kevlar.

I hope to have her painted Ford Grabber Orange, black and some loud yellow.

I hope to pay a friend who owns an avionics shop to wire Mariah Gale.

I expect that most of the metal parts will be powder coated machinery grey.

I am starting a little early because I had to change fabricators to manage my time line.

A host of friends will help me with this large undertaking so I can get her flying before I am too old to fly and because they will add a lot to the adventure and quality of the aircraft.

Please feel free to ask questions and offer advice along the way. My friends on the Rotary Forum were a great help as we changed the engine on the Predator.

I will add to this thread as things move along. We are going to refine the Bill of Materials next Tuesday, May 11.

Thank you, Vance
 
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Vance,

That sounds like an ambitious project, but if there is anyone that can pull it off, it's you. I look forward to watching your progress on this project and wish you all the good fortune in the world as you take on this new adventure. Keep us aprised regularly.
 
Gung-ho------------
 
Alright Vance ! This should be very interesting.

I always thought that you wanted to build a tractor ?

I wish for you to have a safe & speedy build, with great results ! I know that I will be following this thread.
Good Luck !!
 
Vance, how will you manage 12" while controlling tire scrub? Will you use a motorcycle-style longitudinal swing-arm suspension like the one in your early torsion-bar scheme?

Is the goal to eliminate scrub a priority because of the off-airport capabilities desired?

If not, lateral scrub is more elegant than it may appear as scheme for dissipating spring energy for shock absorption, because it doesn't leave you carrying the weight and drag of separate shocks around for the 99 percent of the time you're not using them. The major downside of scrubbing as a shock absorber is encountered when landing on icy runways, something you'll seldom if ever do.

This will be a great build to follow here on the forum!
 
Good for you Vance. I am very interested to see your next adventure. If the past is any indication, you'll have something really nice and practical to fly with and land off road :)
 
I sense already, I'm going to love this thread. Good luck and happy work, Vance!

Kai.
 
Thank you for your support and input

Thank you for your support and input

Thank you for your vote of confidence Doug.

I feel great trepidation standing at the front end of this project.

I don’t understand the reference Jay; I will take it as support.

I did want to build a tractor with a Continental TSIO 550 Chris. It solved cooling challenges and has less drag than a pusher.

I have become enamored with how well I can see from a pusher and the big Continental is very expensive when something goes wrong. I can no longer afford very expensive.

I flew a Stearman at Fantasy of Flight before Bensen Days to reaffirm this choice.

Good input Paul. I know something about managing energy with hydraulic dampening and very little about using tire scrub.

I feel, perhaps incorrectly, that in a zero roll landing that tire scrub will load the wheels and tires in ways that I don’t know how to manage. I feel the response would vary a lot between grass strips and concrete.

I am particularly enamored with the Westland Lysander and the Feistler Storch because of their low landing speed and both use hydraulic dampening and go a long way to minimize tire scrub.

If the landing gear ends up where I expect it to I will use what amounts to a solid axel with two swing arm like links. This requires a space and is not easy to move so plan B is a lower A arm and a Macpherson strut type control. Plan C is a double A arm with a lot of structure for the dampener and spring.

I am trying to minimize bump steer and body roll so the linkage gets a little odd.

Thank you for the vote of confidence Gabor. I have built many things that didn’t work very well without a lot of development and I feel tossed on a sea of ignorance when it comes to aviation.

Thank you Stan, you are like a little brother with unconditional love and an unreasoned confidence. I love having you as a friend.

I would love to have a build thread in the magazine. It would be good writing practice for me because of the wider audience. I will submit something and see how the editor feels.

Thank you Kia, as you can see I am sort of building an MT103 with a Lycoming engine. I look forward to your input.

Hello Scott, great input, thank you. I have struggled with this a lot. It would be very nice to just call Grove up and have them ship the landing gear. I have this unreasonable fantasy that I can do better.

Thank you all for your support, Vance
 
As others have said, I also look forward to reading this thread and if your engine thread is any indication….this will be a great one!

I wondered if you have looked at the Mooney trailing landing gear….I always liked them and they have no tire scrub. They don't have 12" of travel though.
By placing a hydraulic pump on the accessory case it will always be running and even though it is unloaded with a bypass valve, it will create heat. I think you may need an oil-cooler or an air-cooled oil reservoir…..but shoot, you probably already have these things figured out.
 
Yaw Mon Vance B build'N!

Way to go my friend!
It was exciting jus talking about your design but now the building adventure begins.

We know you will do well Vance. You do everything well, what you do not know you learn, and you do not quit until its right so how can you fail?
This is going to be one SWEET ride, I cannot wait to watch the building, and flying of Mariah Gale and some redesign would be fun to watch too.

So it's all good, I got popcorn Vance and Ed so let the show begin......
This is going to be fun!!!!!
 
Vance

Good Luck with the project!! I know you will keep us updated with allot of pictures!!

The Garmin SL40 Com will allow you to monitor two freq at the same time. You can receive and transmit on the active Freq and Monitor the Standby Freq. I have that same one in my Bonanza which allows me to monitor 3 freq's between it and the Garmin 430W.

I remember reading along time ago that to keep the fuselage more of a bullet shape so that changes in the AOA (Angle of Attack) will not induce undesired pitching moments. Maybe some one here remembers that article.......

I would try and keep the fuel outside of the passenger area so that in case of an accident the occupants would be less likely to be doused with fuel and catch fire should the tanks rupture. Maybe some stub wing type tanks???

And I have to ask.... Will it have eyes and teeth???

Take Care.............
 
I'm really looking forward to following your thread on this, Vance. I was very impressed when I saw the Predator on Youtube - the machine (and credit here goes to the designer and the pilot) looks very smooth and very purposeful, it has fantastic visual appearance while flying ...and is truly a great advertisement for gyros (especially, I’d imagine, to 'non-believers', or perhaps the uninitiated). This is the type of machine I'd one day like to own.
 
I share Mark G's thoughts on the fuel, I'd worry about sitting in a bathtub shaped fuselage with it there too - with a Kevlar body it may be possible to sequester the fuel within the airframe, but have it firewalled off in an outer layer? (perhaps also with bladders?)
 
:)Vance, Gung-ho, extremely zealous or enthusiastic.:)
 
Ed leans toward the mouth and eyes

Ed leans toward the mouth and eyes

Thank you Ed, I am a trailing link enthusiast and the way it is drawn now it has one trailing link and one leading link. It is a space thing, if there is enough room there will be two trailing links. These link to my sort of solid axel. The gear may need to be somewhere else and that is when we go to a more conventional A arm/Macpherson strut or double A arm linkage set up.

My testing showed that when running unloaded heat is not a problem if the RPM is reasonable. I intend to test it further in Jim’s shop. I found it counterintuitive.

Thank you John, please keep in mind that this is going to move slowly and the design will change as the build progresses and reality intrudes. One of the things Ed is not happy about is because of the distance she won’t be taking a lot of pictures. She has not even met Jim. I am going to have to take most of the pictures at Jim’s shop. We are hoping to have our T hanger by the time it gets back here.

Thank you Brett, I am glad to have you along. Please don’t hesitate to offer your experience. I am sure the project will benefit from it.

Thank you Mark G. I have learned so much from your design of the Predator. I am embarrassed that the design is so similar. You just got so much right and even the things I am changing doesn’t mean the changes will be an improvement.

I have found several radios that will monitor two frequencies at once. There are several places around here where I am between two airports and I am always uncomfortable not being able to monitor both.

I share your concern about fuel and fire. With 50 gallons on board the challenge becomes larger. I don’t have a good answer. I like the way the Predator does it and it would be possible to get most of the capacity with some tip tanks and still lower the drag. At this time the plan is to keep the two saddle tanks outside the truss but inside the body and a third tank underneath but inside the body. Carbon fiber sort of explodes when you hit it so if the tanks are mounted correctly they should depart the aircraft with any serious impact, hopefully without breaching them.

The paint job is still very much up in the air. Everybody likes and talks about the shark’s mouth on the Predator and that is the way Ed leans.

She did an amazing tiger scheme with feathers in it’s mouth and paws on the wheel pants. I am more conservative and prefer a more Waco style of paint job. The decision will be made once the body exists and we can stand back and look at Mariah Gale. We both like the Ford Grabber Orange.

Thank you Mark E. You should see her fly now with the extra power and a more even lift off. No more dropping the nose to pick up airspeed after liftoff. I can climb out as nice as can be anywhere from 40kts to 65kts. I am glad to have you along.

As I mentioned in the response to Mark G I share your concern about the fuel. Bladders are a possibility. They are heavy but the increased safety may be worth the weight. I have watched enough people recover from burns to be cautious. My Harley shop used to help support the Elisa Ann Rice burn camp for kids that have been burned. That is why we both were nomex flight suits and stay away from polyester.

Thank you for the clarification Jay. I suspected they were words of enthusiastic support. I try to understand what people say. Glad to have you on board.

Thank you, Vance
 
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The sort of solid axel

The sort of solid axel

This is a doodle of the sort of solid axel. The tongue has two motorcycle style swing arms locating it and controlling roll. Most of it would be aerodynamic tubing. There would need to be fairings at the tight corners.

It requires a dedicated space and we will know if we have it when we weigh the frame and engine and tail. I have done weight and balance calculations on everything and it should work but I don’t have an accurate weight of the Mooney empennage and this could mover the axel several inches in either direction making it not fit. Then we will go to plan B or C as outlined in a previous post.

Thank you, Vance

oops, going to the jpeg droped a few lines.
 

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Well so far, buddy the only bad news is the distance and without Ed taking the pictures, the build will be like a box of chocolates, where we are never sure what we are going to get.
However, the rest of the news sounds great. I’m really excited having seen the design so long ago and now the reality of the build.

IMHO it is going to be hard to beat the shark look at least for the Bad A$$ look of a fighter.
 
Oxymoron paint scheme

Oxymoron paint scheme

Thank you for the encouraging words John.

I feel that a Bad A$$ gyroplane is an oxymoron.

The comedic qualities of gyroplane flight were reinforced as I watched the flying at Bensen days.

Glad to have you along. I suspect your aviation experience may prove valuable.

Thank you, Vance
 
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