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Re: REFLECTOR: Something for Nothing? Never

Peter Beaty wrote:

> Alan & Duane,
> This brings me back to my question: why can't I put a parallel valve 540 on
> my standard wing RG-E?

Peter, Duane is in no position to endorse such changes to the Velocity.  He knows
the STD is a well balanced, well tested and well powered airplane as is.  He is

In my opinion, the 173 is a very different case.  Dan designed the 173 himself
without the aid of Ted Yon the NASA engineer who helped us on the STD.  After
flying the 173 I confronted both Dan and Ted together with my center of lift and
CG calculations combined with my flight observations.  They both conceded that
perhaps there was another 2" of aft CG available in the 173.  All three of us
agreed that that was definitely not true with the STD model that we had already
pushed as far back as was safe.

Even ballasting the nose with lot's of batteries has draw backs other than
increasing your dry weight even more.  As we add weight to both ends of the vessel
this can carry momentum aggravating a bucking situation.  John Murfy our local
inspector, very experienced builder and head of our chapter told me once that in
some situations weight in both ends can dampen oscillations but not always.  I
tend to be wary of this train of thought because in boats it is always better to
have the weight in the center and not in either end. Duane has expressed concern
about too much weight in either end to me many times.  He has a lot of experience
in testing mods to these airplanes.

> OK, it weighs [60 lbs.?] more than a 360.

The 540's CG is 3.5" farther aft than the 360 which compounds the problem of the
60 lbs.  The only way the numbers come out is with a 145" canard to move the
center of lift back and then the center of rotation (the mains) have to go back as
much as 4".  These kind of changes should make take-off and landing very fast,
besides changing the configuration (canard aspect ratio) so much that there are
bound to be other surprises.

> Is this REALLY a problem that can't be overcome?

Probably not.  Years ago I saw a small Glasair TD designed for the 0-235 with a
540 that flew great with 6 lbs of lead in the tail.  On the other hand that's on
the front.  All aircraft are more stable with more weight on the front.  With
canards we have to add to the tail for more power.  This is the gest of the

> I agree, weight & balance, c.g., etc, are
> straightforward, but I don't want to be THE test pilot!

With good reason.  It is not just dangerous but can consume a lot of time and