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Old July 29th 08, 12:05 AM posted to rec.aviation.homebuilt
Peter Dohm
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Default The Last Airplane

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...
On Jul 26, 11:18 pm, Anthony W wrote:

I did consider building the TP but after all the discussions about it, I
decided not to. With your improvements, I would sure give it more
consideration. I think I downloaded the original plans but I don't know
if I still have them.
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Dear Tony,

You'd best put a smiley on 'improvements' or you'll have all sorts of
TP supporters dancing on your head :-)

IF... you followed the $80 plans, drilling holes where shown then
trying to bolt the thing together... you'd discover that the plans
were WRONG... and that you'd just trashed a lot of aluminum. Take
that to the fabled 'designer' and he would INSIST the plans were
correct, in effect saying 7" was really 11", that everything fit
perfectly well and that if you had a problem with that, it was
entirely YOUR problem.

That's when you realize the Fabled Designer is a few cans shy of a six-
pac.

My 'improvements' were merely corrections to the drawings. They were
fairly extensive because of the stack-up, in that once you'd corrected
the cross-member dimensions you would have to correct the attachment
of the forward lift-strut, the under-cart V-member and so on.

But there were two areas where the plans violated accepted engineering
practice. One was the lift-strut attachment at the spar, the other
was the attachment of the cabanes to the longerons. Since these
errors are to accepted standards virtually ANYONE who saw them would
understand the need for correction. Indeed, suitable corrections have
been included in the archives of the TP Group.

With regard to the wing & spar controversy, I didn't get that far
along before I realized the plans were some sort of scam and dropped
the project. (At that time I was not aware of Richard's mental
problem.) Indeed, given the price of suitable aluminum tubing, from
the outset I was thinking more along the lines of a wooden wing &
tail-feathers.

What first attracted me to the design was the potential to develop a
light, strong fuselage using matched-hole tooling, a factor that
remains valid.

A wing using aluminum tubing spars and foam ribs is surely the
lightest way to go but the performance of such wings is generally poor
due to the scalloping of the cover. By comparison, a wooden wing of
the Ison type -- the same as used by Leonard Mulholland -- performs
very close to spec, thanks to its rigid leading-edge, and may be
extended so as to improve its aspect ratio.

The simplicity of the design is its main attractant but only when that
simplicity is valid. If your landing gear does not align properly or
your bolt-holes violate the rule for edge-distance, it really doesn't
matter how simple the design may be.

-R.S.Hoover

Just for the record, in a structural sense, the discussion of the lift strut
to spar attachment seems to be related to a hole drilled through the sheer
web. I do have a copy of the plans, which I believe include a reinforcement
sleeve--which I would elect to include.

As of this time, all of the plans I have ever seen for "plans-only" aircraft
require some basic knowledge--especially of which parts will necessarily be
"cut and try" and then trim file or sand some more. That has been equally
true of the Vari-EZ and all of the other designs that have appeared around
my local chapter. That has also been true of the "fast glass"
kits--especially the early ones.

So, I am not dissapointed by the fact that a set of drawings, which were
made following the construction and flight of a homebuilt aircraft, won't
result in parts that bolt together as thought they were the result of a type
design. I have no right to expect such a thing!

Peter
Just my $0.02