Homebuilt followup

[Chairboy]

As some of you may remember, a couple months ago I began thinking hard about building my own plane again.  Well, in the past few weeks, I decided to just do it.

I've placed my initial order for supplies and plans to build a Cozy Mk IV, a composite canard aircraft that's based on the Burt Rutan LongEZ (it actually has his blessing).

I've faxed in my license agreement and have spent $1400 on foam, fiberglass, epoxy, a ratio pump, plans and other miscellaneous things needed to start the bulkhead chapter.  

I plan to power it with a Mazda rotary engine which will be turbo normalized.  I'm considering using an IVO in-flight electric adjustable prop configured to be a constant speed prop, and estimate it will take approximately 2,700 hours to build.

Here's the webpage I've started to document my progress, including some early thoughts on panel design (it'll be hopelessly out of date by the time I need to buy avionics, but it's still fun to dream) and the modifications I plan to make.

http://hallert.net/cozy/

Since the paint scheme is the most important thing to determine before actual construction begins, here's an image from http://hallert.net/cozy/paintideas.htm:



Ok, let the beatings begin.  To help keep things organized, I've anticipated the following main areas of criticism.  Label your post appropriately.  

* Rotary?  Are you stupid?
* Composite?  Why not an Vans RV aluminum plane, you commie?
* ROTARY?!
* Your paint scheme is going to melt your airplane, don't you know anything about Tg?
* Well, have you considered a Lycoming instead?
* Modifications?  Ha ha ha ha, you gonna die boy.

I'm sure there are more, these are just the biggies.

[midnight Target]

Cool Chair. unless of course you actually fly the thing.

[Vulcan]

Hispano's or .50's?

[Ripsnort]

Originally posted by midnight Target
Cool Chair. unless of course you actually fly the thing.

Good luck Ben! I've always wanted to do that, still may, but I'm waiting on retirement.

[LePaul]

I thought you had just lost your job?  Or has new employment come thru?

Rotary....eh...good for cars...airplanes...well...I havent heard a lot of great things.  I'd stick with something more known (Avo-Lycoming, etc)

Canards are pretty...you dont see em a lot.  Im kinda undecided if Id ever want one or not.  For every bad thing I hear, I hear and equal amount of good, so its a wash.

[Roscoroo]

nothing wrong with Rotary engines .
Good points
they have the ability to run at very high rpms without major damage 12,000-15,000 rpm .
they make decient Torque at 5000 +
I remember they go more hrs vs a piston eng befor a major overhaul
(I'm not shure on the hourly amount )

possiable bad points
they need a very good oil cooling system
The exhaust when ran with just a header is EXTREAMLY HOT and produces alot more heat then a piston eng.
You will have to intercool the turbo also.

More later as i remember from my ole "Rotory drag racing days"

[LePaul]

Whoa this turbine powered one  looks mighty cool....



The guy who designed the Mark 4 also started out with a BD-5 years ago.  Great read

[eagl]

A few years back, the subaru engine mods were all the rage...

Cozy is a nice model.  A bit porky in my opinion, but that means roomy inside and it's still a very efficient design.  Not a good plane for acro, but it sounds like you're going for cruise efficiency and trips over local fun-flights anyhow.

I've always wondered how they'd do with a nice turboprop...  Nasa sponsored a bunch of small turbine designs to help spur the introduction of turbine tech down towards private aircraft owners, but so far they've only made it into the VLJ business market.

[Captain Virgil Hilts]

I'm not real sure about the engine choice.

Were it me, I'd do a big bore (94mm VW bug jugs and Rabbit rods) Corvair with a small turbo and budget EFI based on a GM engine management system. The Corvair engine is VERY popular with the home builders, and the Corvair hot rodders have done a real good job developing the stuff needed. Provided you duct enough air to cool it and use an adequate oil cooler, you'll have plenty of power, reliability and simplicity.

[eskimo2]

“You’ll shoot your eye out with that thing!”

[Holden McGroin]

Originally posted by LePaul
The guy who designed the Mark 4 also started out with a BD-5 years ago.

Burt Rutan was on the original BD-5 design team.

[Chairboy]

Originally posted by LePaul
I thought you had just lost your job?  Or has new employment come thru?

Still unemployed, but I got my severance check, wife is working, so...  I figured that I'd work on my project while looking for a job.  Better than sitting on the computer.  Compared to a Vans RV, the initial cost is pretty low to get started.

Originally posted by LePaul
Rotary....eh...good for cars...airplanes...well...I havent heard a lot of great things.  I'd stick with something more known (Avo-Lycoming, etc)

There are plenty of gravestones out there associated with Lycoming.  They aren't anything special when it comes to reliability, their only 'virtue' is that the degree of how unreliable they are is well documented.  Just about every pilot I know with a few thousand hours has had at least one engine failure, usually more.

Rotaries are unproven as of yet, but 26 moving parts versus 3 moving parts...  that's a step in the right direction if I heard of one.  There are plenty of 'em flying, some of them over a thousand hours.  The reliability info is being established.

Originally posted by LePaul
Canards are pretty...you dont see em a lot.  Im kinda undecided if Id ever want one or not.  For every bad thing I hear, I hear and equal amount of good, so its a wash.

I really like a few things about canards:
Stall resistance: The canard stalls before the main wing, so it's wicked hard to get it into a spin, and if you sit there at idle with the stick pulled all the way back, the nose will just bob up and down gently as the plane descends.
Efficiency: Unlike a conventional setup, both lifting surfaces produce lift.  The tail of a normal plane produces downforce, which increases the energy/fuel needs and slows the plane down.  
Sexiness: It looks like a space ship, and that's what I want.  Heck, check out the paint job.  

[Chairboy]

Originally posted by Vulcan
Hispano's or .50's?

I'm gonna troll the military yards to see about standardized hardpoints that I can use for the baggage pods.  If I happen to be able to mount a stock .50 cal gunpod from the same point and there happens to be a lead to it that's triggered from the cockpit, well....

[Chairboy]

Originally posted by Captain Virgil Hilts
I'm not real sure about the engine choice.

Were it me, I'd do a big bore (94mm VW bug jugs and Rabbit rods) Corvair with a small turbo and budget EFI based on a GM engine management system. The Corvair engine is VERY popular with the home builders, and the Corvair hot rodders have done a real good job developing the stuff needed. Provided you duct enough air to cool it and use an adequate oil cooler, you'll have plenty of power, reliability and simplicity.

I'm not a big fan of piston engines, too many moving parts that fail catastrophically.  If I was going to stick with auto conversions and not do a rotary, I'd be more likely to use a Subaru.  It's the right mix of power and reliability and there are a LOT of them flying.

It's amazing how well the VW engines do, the Sonerai does 200mph on one of those.

[capt. apathy]

for some reason the idea of building (And flying) a homemade aircraft reminds me of one of the lines from Serenity (the landing scene just after credits)

pilot "this should be interesting"

captain "define 'interesting'. "

pilot "oh God. oh God. we're all gonna die."