These are not YOUR airplanes - Was: High Cost of Sportplanes

On Mon, 19 Sep 2005 01:12:41 -0700, Ron Wanttaja
wrote:

On Mon, 19 Sep 2005 03:47:38 -0400, Roger
wrote:

On Sun, 18 Sep 2005 23:37:30 -0400, "Gordon Arnaut"
wrote:

Evan,

I don't want to drag this out, I think some good points ahve been made --
however, I don't see why fiberglass airframe construction is going to be
less labor-intensive.

Once you have the moulds constructed, fiberglass lends itself well to
making large compound structures as one piece.

There is almost zero opportunity for automation in fiberglass construction,

That depends on your thinking. Fiberglass composite also lends
itself well to putting pieces together.

I dunno, Roger. I've been both to the Glastar factory and the Vans factory. At
Vans, a guy feeds a big piece of aluminum into a big CNC machine and

Agreed, we'd have to change the way we approach the parts making
process particularly with fiberglass, but I think when it comes to
mass production much could be automated. OTOH when it comes to mass
production, the old automotive approach where one press stamps out a
whole bunch of parts ain't a bad way to go. Maybe that was a poor
choice of words as I worked in a metal stamping plant many years ago
in another life. People left a lot of parts in some of those presses.

whango-whango-whango out comes a big pile of RV parts. But then I go see the
Glastar's fiberglass fuselage made, and its spray the release agent onto the
mold, then the gelcoat, then cut pieces of fiberglass and lay them into the
mold, then squeegee on some resin, then apply the foam, then apply another layer

Squeegee? They were using really big paint brushes to apply the vinyl
ester resin and moving a lot faster than I do. Slop it on, squeegee
it out, It's no wonder then have the water line 100 off by only a
1/4 inch on the pilot's side and missed the cut out for the horizontal
stab by about three inches on mine. :-))

Looking at the size of one of those fuselage shells, two layers of
fiberglass, half inch of foam, and two more layers of fiberglass.
Vinyl Ester Resin is not noted for taking a long time to gel and has a
notoriously short pot life, unless you work in a refrigerated room.

of fiberglass and more resin, etc. etc., lather, rinse, repeat, then let the
assembly tie up your every expensive mold while the resin cures.


Add heat. It really speeds things up:-))
But, yes, the way we do it now is very time consuming...and expensive.
Metal working is a much more mature field while glass/composite is
still relatively new.
I think "Vans" has done a great deal to speed the production and make
the parts go together faster.

Speaking of Glasair. I have over 1100 hours into those nice looking
parts and they are *almost*, *starting* to look like they *might* be
related to an airplane. There's a reason the "jump start" G-III is
expensive. sigh. Of course had I started in and kept at it, mine
would be flying now, or they'd have fitted me for one of those tight
fitting jackets with the long arms that wrap around.

The G-III has a lot of possibilities for streamlining the building
process and not just by having the factory put a bunch of parts
together for the builder. Of course the G-III is one of the most labor
intensive kits out there so it has a *lot* of room for streamlining.

One time consuming area is the firewall along with the engine mount
attach point reinforcements. There are 6 attach points. Between them
you are looking at 96 individual lay-ups.

Looked to me that manufacturing aircraft parts in fiberglass is a *lot* more
effort...though I allow that less-skilled workers can probably be used.

I think they were training a new one when they did the shells for
mine. As far as skill though, I think the only reason that is possible
is the tremendous excess strength built into the designs which make
them tolerant of far less than perfect construction technique. After
all, I'm building one... OTOH I may never get it finished.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


Ron Wanttaja

P.S. Wanna hear something *really* scary? My spell checker passed
"whango-whango-whango" but hiccuped on "gelcoat."

I find mine often fails on relatively common terms. It thinks Gelcoat
should be gel-coat.:-))