> however,
> it became apparent that there is a dip just in front of and just behind the
> spar. It is only small, and cannot be seen in normal lighting conditions. I
> would say that the dip is about 0.5mm deep approximately 2cm either side of
> the
> spar.
>
> a) Leave it alone as its effect on the airflow over the wing will be
> negligible
.5mm across 2cm is many times the tolerance to preserve low-drag laminar
flow. www.ar-5.com (see Kitplanes article) has more info, but don't buy
the Arnold Tape. I used a dial indicator to find the waviness, as did
Arnold by an even more time-consuming method, and found waviness in
excess of tolerance cannot be felt by hand, nor seen on a glossy painted
one. So, if not desiring to go as far as he did, I'd at least get rid
of the depressions which are that apparent.
Best,
Fred F.
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