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Old March 23rd 07, 07:34 AM posted to rec.aviation.homebuilt
Roger[_4_]
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Posts: 677
Default Whose airplane is it anyway?

On Sun, 18 Mar 2007 23:25:24 -0400, Ernest Christley
wrote:

Richard Isakson wrote:
"Richard Riley" wrote ...

Well, do check with them for your own peace of mind, but there ain't
nothin - and I do mean nothin - that he can do. It's faintly
theoretically possible that if you include his name in the registered
name type of your airplane he could have grounds to sue you, but it's
never happened and probably never will.

Just to be on the safe side, call it something else when you register
it.

Frankly, the big change that needs to be done to your airplane is it
needs fixed main gear and a lower ground attitude. One man's opinion,


Yet, as Lieutenant Edwards found out a great deal of care must be taken when
you're dealing with changes in the center of gravity of flying wings.

Rich



I've taken painstaking care not to move the CG or change the airfoil,
sweep or angles of the wings. I have made the nosegear fixed. That


Lordy, When I flew Jack Yoder's Barracuda, there wasn't much he hadn't
changed and it flew well. The wind root sections that contain the gear
were modified to symetrical air foild as he went to wide profile tires
for dirt strips and the root thickness wasn't enough to hold the
wheels. I'm not sure if he moved the wing a bit on that one due to CG
of not. If the CG falls in the correct place on the wing it's usually
considered a good thing.

OTOH he put a 260 HP 6 on a GP4 designed for a 180 HP 4. It was a fun
air plane to fly. It took some doing with no break out force or stick
gradient in pitch. Roll forces were just fine. He had moved the wing
but it could still end up in an aft CG situation. Tiny tail and aft
CG is not a good combination.

saved me 10lbs, lots of complication, and several failure modes. It may
cost me a couple kts, but I consider them kts well spent. If I knew
then what I know now, the main gear would be aluminum leaf springs.
There's lots of weight in the gear retract mechanism, but its fairly
evenly spread forward and aft of the CG.

As for changing the ground attitude...you've got to get it high enough
to put a prop on there. I do have less than 9 degrees nose-up, which is
the limit. It's just under 8, if I recall correctly.


Much nose up attitude when on the gear can make for some interesting
take offs in *some* planes.

Actually in some areas we have a lot of leeway and onthers very
little.
On some planes you can move the wing fore, or aft to fine tune the CG
with no problem and on others the change in coupleing can be
pronounced.

Any time you change something from the original design you may end up
in untested territory, unless it's a popular mod.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com