Beechcraft Starship

[Jim Sower]

The 51% rule and prohibitions against "operating for hire" would preclude any homebuilts that could seat more than four people. There's no rationale or market for a homebuilt cabin class airplane. Even the single- and 2-place jets don't succeed (but that's largely because hardly anything Bede does succeeds much). I think if I won the Lotto I would go lean on Burt to certify or kit out the Boomerang. That's the only even remotely cabin class [twin] that I would be interested in, and if I had one, it would rarely fly with all the people on board that it would hold.

 

I just can't do the mental gymnastics required to fit a cabin class airplane into the "Experimental" definition.

[Dave Clifford]

The 51% rule and prohibitions against "operating for hire" would preclude any homebuilts that could seat more than four people.<quote> What do you mean by this Jim? AeroComp has been marketing a 7 place kit for years and the Murphy Super Rebel is a six passenger kit plane they have been marketing for several years also.

[No4]

There is an Aerocomp 10 seater (similar to Grand Caravan) on floats with a Walter turbine that operates out of Nelson, NZ. Very nice rig. There is a monster taildragger called a Sherpa ( I think) with an IO-720 that seats 8 also for sale as a kit.

 

A homebuilt turbofan or business turbo prop for commercial ops is a bit different, it's speed will be limited by Mach number, requiring very high external finish, and internaly there is the undercarriage, very expensive engines, powered flight controls, anti ice, pressurisation to 40,000 feet and some serious avionics to install like weather radar, tcas, inertial nav systems, auto pilots, and flight management computers. To build it yourself and sell it your skills and knowledge would have to be to an extremely high level. Unlikely to be popular with the hoi poloi who sign the cheques.

 

However to homebuild a 10 seater for experimental use , if you knew what you were doing, would be no harder than building two cozys. It's cost and time would be proportional to how complex, how fast, and how high you want it to be.

 

Burt pulled out of selling plans because of lawyers sueing him every time an EZ crashed; with 8 dead rich folk alot of lawyers would be after you.

 

The Starship won't be re engineered with jets, but Burt has several composite turbofan and prop designs on the go. The Avanti is not so dissimilar, in fact the three flying surfaces can be considered superior to the canard.

[Jim Sower]

<... AeroComp has been marketing a 7 place kit for years and the Murphy Super Rebel is a six passenger kit plane they have been marketing for several years also ...>

Agreed. I would not have said what I did on a thread around Maules and BD-4s on steroids and the like. This is the Beech Starship thread, and up until now we were talking about high speed, high altitude, complex, cross country airplanes - "cabin class" twins or better. I'll stand on my statement that that airplanes of that type do not lend themelves to homebuilding, and even if you had one, you would be very hard put to legally get proper utilization out of it. I don't have that many friends going to the same place at the same time.

 

Big old boxy planes like those you mentioned that haul a ton or two of freight around at 120 kts are another matter altogether and, IMO, are more appropriately discussed on a thread of their own since they have so little in common with Starship, Avanti, etc.

 

The price I pay for making general statements .... Jim S.

[marbleturtle]

I wouldn't want to build a 10 seater... but a six would work well for me. How about a Limo-Cozy?

[No4]

Don't know if you are serious marble, but I have been pondering that problem very hard.

I desperately want to stick as per plans, but the cozy is just too small for me. I've been working on widening and lengthning the fuselage, but it's a recipe for disaster. What to do with the wing, rudders, landing gear and canard???

A set of Defiant plans are mine for the taking, but they say 6000 hours to build the bugger.

Life is tough with these difficult decisions!

 

The King Kozy's website hasn't been updated for several years, it would have been interesting to see that fly.

 

Back to the aerodynamics text book!

 

 

[Jerry Schneider]

Lengthening would be a real challenge, but, if you're tall, you might consider moving the front seatback aft an inch or two with out affecting moment very much... especially if you're on the heavy side.

Widening, OTOH, shouldn't be too difficult, and it's been done (and flown). You would be amazed at what 2-3" in width makes in the feel.

[John Slade]

One simple way to widen the hip space in a Cozy would be to cut away a curved area of foam on the inside of the armrest parallel to the torque tube and make a glass to glass bond in that area. This way the armrest could move outward (toward the torque tube) an inch or more from the plans position. This would buy you extra space where you need it most for minimal modification.

[marbleturtle]

Length is actually okay for me. At six feet, I may raise the canopy a little since my head was right up against the canopy, but leg length was good. Width is okay for me at the hips, but shoulder width is a problem. I've decided to go 2 or 3" wider each half of the fuselage all the way back. (4"-6" total added width) I've read a couple of people write that they widened the front and then tapered to the standard width at the back. I don't want to try that because I dont want to re-engineer the longerons and floor for a new shape. Just think of what I want to do as taking a band saw long ways down the fuselage and widening the sitting space and leg space by 3" all the way back. No new shapes. Same wings, 6" wider canard spar (inside fuselage), 6" wider main wing spar, 6" flat spot top of canopy.

 

There would be a change in shape around the Turtleback, no need for the leading flares that blend into the engine cowling around the Lyco cylinder heads, but I would make that change regarless because I'm leaning toward using the Rotary. It does not protrude out the side like the designed Lycoming. There is also the consideration needed for the added frontal area of widening the fuselage and the added drag. I don't remember the exact calculation (time to drag out the aeronautics books), but increase in resistance is a geometric function in relation to increase in frontal area or flat plate drag. I'm looking at 250 HP which more than offsets the added drag. I'm also leaning toward retractable gear which will offset some of the added drag.

 

I'm not an expert, so I can't recommend doing this. Some people would even argue that it is insane to make any changes to the design. The Cozy was an extreme design variation of the Long EZ. Taking an aircraft design from a "single wide" to a "double wide" is a big step. I think what I'm considering is more of a baby step forward, and evolution of the design instead of a revolutionary new design. That said, I still need to take the time to study the changes and make alot of flight tests at the end to verify that flight characteristics are still sound. I could spend 5 years building only to find out I have a propeller driven brick.

 

I too wish the King Kozy had been finished and flown. Its certainly easier to follow someone else's work.

[No4]

I guess we killed the starship thread, but what the hell....

 

I was listening to a Flight test engineer give a talk recently, he was talking about the different approaches used by Russian aircraft designers, and British. He said the Brits usualy start from scratch, and there is lots of re inventing wheel going on along the way. The Russians keep a huge database of what has been tried before and how succesful it was, and you only start designing something new if it hasn't been done before. He said he was talking about an unusual Spitfire radiator system to some of them and this guy jumped up and came back with an enormous book of radiator designs with the system right there.

 

Well thanks guys, you are my Russians!

 

I've pretty much come to the same conclusion as you Marble, run a bandsaw down the middle and widen the whole thing. It appears a reasonably basic modification. The drag will increase, but I don't know how to calculate it accurately. Your parasite drag will increase, and also some induced drag. But it should also now be a bit more of a lifting body, so the lift to drag ratio will not be so badly affected. Definitely more horsepower required, but the rotary should easily cover it. The difference between an Ez and a Cozy is 40 hp, so another 40, ie 220 hp should easily cover it. Just to be sure I'm going for 400 hp.

 

I don't want to stretch the fuselage at all, but considered it from a weight and balance point of view because I plan to have such a heavy engine hanging out the back. I don't think it will be neccesary. I plan for mine to be a two seater, with the rear seats converted to luggage space, long range tanks, and mount the radiator, intercooler, and oil cooler there also. Thanks for the advice John (she's looking good ) and thanks and yes Jerry I'm 6'4 and 220lbs.

 

I initialy was a great tout for retracts and constant speed props, and from a theoretical point of view they are much superior. But the gear is expensive, and I would constantly be worrying if it was working or not. For me the weight, complexity, and reliability are not worth it. I'd love a constant speed prop, but to get one for auto engine is hard/ impossible, and the ones I have seen require lots of expensive maintenance, after a large initial outlay.

 

I've decided to spend all my money on horsepower (decisions, decisions), I think that is the most cost effective way for me to satisfy my need for speed .

[marbleturtle]

Oh... No4 brought up a good point I forgot to mention. I hope to keep the weight in check using a lighter-than-plans rotary engine, but I may go 3 rotor and over-power it (400HP... hehe). I'm looking hard at developing my own glass cockpit with solid state gyro, pitot, gps, et al that would replace ye-ol-steam-guages. Chucking the mechanical stuff should save some weight. I may need to shove a few items in the nose to keep balance in check, but I'm looking at extending the nose some to ease the transition of a wider body. With the nose cone extending a few inches further out, it will give me a little more leverage against C of G using less weight.

 

Hopefully I'll keep empty/gross weights close to normal despite the 6" worth of glass and acrylic nose to tail. All that work will be for naught if I end up with a 400 lb useful payload. I'm not going to compensate for heavier gross trying to use higher speeds. I don't want to play Concord on final. I don't want to re-engineer anything. I just want to add a teaspoon more of brown sugar to Uncle Nat's cookie recipe!

[Jim Sower]

Ever wonder why all the designers are so damn puny and scrawny? Don't you just HATE that sh*t?

 

That said, let's not get all crazy and stampede into some hideous fuselage expansion project. Skill and deception always win out over superstition and black magic. I'm 6'3", 250#, 38-39" sitting height. I doubt anyone on this list has much more shoulders and ass than me I sat in John's box stock fuselage and discovered a couple of things:

 

1. No need to lengthen anything. There's plenty of leg room. Maybe (but I sereiously doubt it) move the seat bulkhead back an inch for CG considerations (more on this later).

 

2. If I recline against the head rest, I don't hit the canopy. My headset probably would Certainly if I had more than 1" of seat cushon under me. But I needn't since I carry much more than adequate padding with me wherever I go:) Also, canopy interference is largely due to the canopy x-section being round all the way - that is, it's moving toward my head as it rises - the only really high point is over the center console where it benefits nobody. My solution is to slightly modify the canopy frame and have Todd blow me a canopy that basically comes straight up from flush with the fuselage sides and then makes a sharper turn to cross over my head. Sort of like a Glasair.

 

3. To accomodate my big fat ass I mean to widen the ENTIRE fuselage by 2". That means add 2" to EVERY bulkhead, spar, etc. If I do it that way, I don't have to re-engineer the taper on the fuselage sides and nose and turtle back and deal with all those "unintended consequences". Besides the two inches of fuselage, I will do what Slade recommends and gain 2" more by eliminating [most of] the center console, and cheat another nearly an inch on each side by skinnying up the side consoles. That's 5" - 6" butt room, of which only 2" is apparent to the airstream.

 

4. Besides the 2" wider fuselage, I will pick up another 2" or more shoulder room on each side by bringing the canopy up from flush with the fuselage sides instead of having the plans frame curve in a couple of inches on each side before the canopy even starts. Wife unit can slouch outboard a little if that's really necessary (which I doubt). Anyway, that's a total of around 6" shoulder room for that same 2" of visible expansion of the bulkheads.

 

I aim to compensate for all that lard by building the canard to the original specs (6" greater span - and of course add the two for the fuselage mod). Since I'm going to have a rotary, there will be no cowl cheeks (perhaps even a "recovery curvature" in the aft cowl and that should wash out any drag penalty aft. Additionally, I aim to make the Cozy equivalent of the "Long nose" mod so many EZs have. I will make the nose at least 6" longer, but instead of bringing it to a point, it will have much more gentle lateral taper and end in sort of a 6" or so wide "wedge" snout - like a shark. Should look kuel as all hell. Snarky. This configuration will produce a little lift (more fat ass compensation) and help correct for the fact that the moment arm for big fat pilots is significantly less than that for little puny guys (it's like our personal CG is further forward than their's).

 

All together, I think I'll have a sleeker looking airplane, but if I want to call it a Cozy, Nat will probably want me to use letters much wider than they are high and perhaps add an extra "o" or "z"

 

It's a substantial mod already. Don't make it needlessly more difficult .... Jim S.

[Dave Clifford]

Jim Sower,

Do you REALLY need to add the vulgarity in to your posts or do you just not know any better??? Been to Crossville, my guess is you don't know any better!!