Vans RV-G glider

Earlier, (Mark James Boyd) wrote:

Is it possible to make a retract gear metal glider with
flush rivets and a carry-through spar which would give
40:1 ratio...?

Yes. All it takes is good attention to detail during construction. And
after that, it takes microballoon mix, primer, paint, and lots of
sandpaper and elbow grease, reapplied biennially or as necessary. The
old Sierra Press soaring books are rife with takes of re-refilling all
the dings, rivet dimples, and seams in the old HPs, Prues, Schweizers,
and Laister ships. Been there, done that, got the bondo-smeared
T-shirt.

I remain firm in my conviction that the most cost-effective way to
achieve the smoothness and fidelity to contour required to get 40:1
glide ratios is with female-molded composites. Dick V. knows this from
his soaring contest experience. It's not the only way, and it's not
the best way for everybody or every situation. But where (quantity
~3), it's pretty much the cheapest and least labor-intensive way.

It's why I'm spending a ton of money making full-size wing molds for
the HP-24 and its derivatives. I spent years messing around with
various sheetmetal and moldless composite schemes. And every path led
back towards female-molded composites in full-size molds. So I'm
making wing molds. Some say I've gone over to the dark side. But once
I finish the molds, these wing sets will darn near build themselves.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

Why would anyone even consider building a metal glider when you can buy the all
composite Apis 13 or 15m kit with 400 hrs. build time. There is just no
reasonable way to duplicate the accuracy of a glass airfoil in metal. Were I
inclined to build a glider the Apis would be it.

JD

Laister LP-15 Nugget.. all metal wing, bonded like the Grumman's of old AA-5
etc.. no rivets showing.. reflex flaps.. SSA book says 36/1.. but it's old
technology..

BT


"Mark James Boyd" wrote in message
news:3fa6166d@darkstar...
Hmmm....

I was wondering if metal gliders have an L/D disadvantage
due to the metal, or because of the lousy rivets and
poor wing airfoil and draggy struts (of the SGS gliders,
for example).

Is it possible to make a retract gear metal glider with
flush rivets and a carry-through spar which would give
40:1 ratio, or is metal just a substance that won't
allow the shapes or fine tolerances needed to make such
a wing?

Vans seems to do an excellent job selling very high
quality kits with very nice wings (metal). I wonder
if they'd consider selling a Quickbuild glider kit?

The Peterson Javelin was built mostly out of metal and domed rivets.
The company carried out tests on the rivet shapes and reckoned there
was no difference between flush and domed. Furthemore they obtained
thier own 'cheap' rivets which they had FAI approved which saved them
a fortune.

The report can be found on the SSA website under the articles on
flight tests of various gliders.

Of course this relates to the 'then' technology, 'now' may be
completely different

(Vince C) wrote in message . com...
The Peterson Javelin was built mostly out of metal and domed rivets.
The company carried out tests on the rivet shapes and reckoned there
was no difference between flush and domed. Furthemore they obtained
thier own 'cheap' rivets which they had FAI approved which saved them
a fortune.

The report can be found on the SSA website under the articles on
flight tests of various gliders.

Of course this relates to the 'then' technology, 'now' may be
completely different


And as a result the Javelin was a medium-performance glider, with no
laminar flow over the wing. The design goal was low cost, not
performance (which explains the identical tail control surfaces and
spoiler roll control.

An interesting glider - I flew a brand new one once at the old
Vacaville gliderport back in the late 70s - OK performance but really
poor glidepath control and somewhat odd roll control. Sadly, the
following day it crashed (during a landing attempt, I think) and the
pilot was killed. I remember not being surprised by the accident,
which I think was a high pattern resulting in a low 360 attempt and
the classic stall/spin on final. Not a slam on the glider - it was
just different.

I cringe when I see gliders tied out for long periods - even poor
little 1-26s. At least hangar the little things! Especially now when
something like a PW-5 or Alpis can be rigged and ready to go in 30
minutes - clean, no bird droppings, no hangar rash, and with a really
detailed preflight inspection (at least that is how I treat my
assembly process..).

To me, a lot of the fun is the whole rig-tape-wash-setup
cockpit-pushover ritual that leads to a soaring flight. As long as it
isn't a Lak-12 or Nimnbus 3 - of course!

Kirk
Ls-6