choice of fuelage construction

I'm not a REAL metalworker (hacker, perhaps), and I'll probably never build a homebuilt, BUT, here are some observations that I have from reading about many different types of aircraft and their structure.

Welded steel and riveted aluminum construction has been around since the

1930's. Presumably they are both good, solid ways of doing things. Wood is good as well, except that if you don't keep it hangered it weathers much faster than metal. Welded aluminum should be as good, in theory, as welded steel -- but aluminum welding didn't come along until much later. I'd be a bit concerned about fatigue cracking, but only to the point where I'd want to make sure the manufacturer has thought of it and taken steps to deal with it.

If welded steel, welded aluminum, riveted aluminum, wood and composite were not all viable methods of building aircraft you wouldn't have new aircraft using them in their construction. If there were one clear winner among the various technologies you'd have all the aircraft in the world being built with that -- and you don't. If there _is_ going to be a clear winner I think it will be composite -- but I'm not holding my breath.

I would buy whatever technology I thought was coolest, and the one that I thought I would be able to work with. That means that if I got aluminum I'd make sure to take a class in TIG welding that included aluminum, and I'd make sure that I bought a TIG welder and assured myself that I could handle it. Ditto with steel, although from the web site you supply it looks like I could use my oxy-acetylene skills -- which is a cool thing for me, because it's the only kind of weld that I produce that I really feel is first rate.

Having said that, if I were going to build a homebuilt I'd probably look first at the Pietenpol air camper, which is wood. Why? Because they're funky and I like them, because I could probably cage a model B engine from my brother and I like the idea of hopping one up for aircraft use, because I have a promise from a friend that if I build it he'll teach me to fly in it, and because it's just a giant wood model airplane which I have lots of experience building. I _might_ build the fuselage out of welded steel tubing, but if I did the Pietenpol purists _might_ have me drug off and shot -- it would be a risk I would have to factor into the decision.

Tim,

Thanks for your input.

Well your in luck you responded to me. Amazing! Absolutly.

I went over and got a workbench last Sat from a guy.

Guess what is hanging in his garage with several other pieces. The fuselage..and he has plans

And guess what, he is being relocated in his work and wants to sell it.

Interested..?

I wld imagine it wld be fairly cheap.,

I can give him your email if you want to buy it. He was hand drafting the tail section. I told him I cld do it and print it out so much faster in acad and it wld be very accurate. He was making templates. The guys an EEA member seems pretty knowledgable.W

BR.

Yeah thanks John I made a mistake there..It is steel.

Which in my mind wld be better in a crash at absorbing more energy than Alum.

Tim,

here's what he says abt the plane:

Pietenpol Aircamper Project

• Substantial progress on wood fuselage and tail section. * Approx. 13 ribs built, rib jig, spruce and ply on-hand. * Numerous parts, hardware, cables, etc. * Building for Corvair conversion (have engine also on hand-to rebuild, etc. If interested, can include for no extra cost), can also use other powerplants. * Bought new plans set for it, including 3-piece wing plans, from Don Pietenpol-no marks or wear on plans. * Bought to finish, but having to sell because of pending out-of-state move--breaking my heart. * Acquired for 00.00, make decent offer and it's yours. Will consider delivering to local commute area.

Let me know if your interested. He cld prob send ya some pics..

Blueraven

Where?

Agh! Oh that sounds tempting.

But I'm not ready to start on something like that now, and if I've learned anything by now it's to not start projects unless I'm going to really, truly finish them.

WRH

I have a business, Aircraft Welding Works, that does repairs and mods to 4130 tube airframes, and S/S exhausts, and aluminum fuel tanks, etc. I am also AP-IA FAA mechanic. So the question as to which is better: tube frame or sheet aluminum construction, depends on what you want. I think 4130 tube frame is easy to fabricate, and repair, and most crashworthy. But I am a welder. A sheetmetal magician may disagree.

The bearhawk is an excellent design. I have followed it's development, talked to the designer, and have a set of plans. It combines the best qualities of tube and sheetmetal.

Good luck, Scott.

Tim,

You cld buy it and hold it till your ready to build it. In asnwer to the other guy, he's inn Anchorage alaska and his email is..Rob Spoo

PS; I liked your PID article. I'll be doing that when i build upgrade to my distilling plant.

Can u make something to scan something with a laser, indentify it and then drop it via gravity into a container?

Take Care.

Ah, but I'd have to store it in a way that when I _did_ get to it it'd still be flightworthy.

Glad you liked it. Send me mail when you get distillery on line. Keep in mind that for many process control tasks you don't need to make a custom controller -- you can buy PLCs and all sorts of other industrial pieces either new or from eBay and whomp up a system with much less effort than building from scratch.

I _could_ but I think there are already things out there that do that -- do a web search on computer imaging, or perhaps industrial computer imaging.

A number of years ago I researched kitbuilts just like you are doing and ended up buying, building and flying an Airbike. It was all welded 4130 and stronger than hell. I really dumped it hard on a landing or two and it just bounced back with no damage at all. I have seen an riveted aluminum ultralight do a bounce just like I did and the gear collapsed and bent some other empennage. Maybe the circumstances were the same, maybe different, but the aluminum airplane still broke. I flew mine for about 200 hours and then sold it.

Good luck and good flying

As a bearhawk builder (not at the fuse yet), This is a terrific plane. If you want to go the quick built route (about 32K), the fuse is all welded, 4130 STEEL tubing. The wing is 2024 and 6061 aluminum held together with bucked rivets (with a few pop rivets in tight corners of the controls surfaces). The wing uses a beefy built up spar, and with everything together, results in a very strong wing. There are support goups on Yahoogroups. Bearhawk, bearhawkers, and bearhawk built. There is also a how-to CD by one member, and a series of construction manuals by another member that are must-haves for any bearhawk builder.

I'm guessing about the "other" plane you have in mind-probably a Zenith

701 or 801? Or the murphy aircraft model whose name I can't remember? All are good designs, but the zenith series are not fast, and they don't have much cargo space-very small!. I don't recall much about the murphy plane (moose?), but they are much more expensive.

One advantage of the BH is that it can be plans built-you don't need a kit. So can the 701/801, but not the murphy series of aircraft.

John

John,

You said One advantage of the BH is that it can be plans built-you don't need a kit. So can the 701/801, but not the murphy series of aircraft. >>

what did u mean by 'plans built-you don't need a kit. So can the 701/801, but not the murphy series of aircraft. '

thanks

BR

By that, I mean you get a complet set of plans with the Bearhawk, 701 and 801 that could could completely build the plane from scratch. OTOH, the murphy series of aircraft are built from kits. They won't have all the dimensions for the parts in the plans

What this means, if the company making the KITS goes belly up, those with scratchbuildable plans can still finish theirs. The non-scratchable plans owners are SOL unless they have the complete kit.

John