Building “light” is a mindset that needs to permeate every
aspect of the project from the very beginning.
Keeping It Light
Amateur-built dietary control
BY BUDD DAVISSON
AN OLD HOMEBUILDING ADAGE says, “You know a part is light enough
when you lay it on the bench and it floats to the ceiling.” Why this
weight fetish? Why is it that almost every airplane is too heavy? And
what can we do to avoid building pudgy airplanes?
Weight is one of our primary concerns because an airplane is
nothing more than a clever device for temporarily suspending gravity, and gravity feeds on weight. In fact, the only reason the term
“weight” exists is because gravity is there to make us feel it.
It’s important that we realize that building light is a mindset
more than a skill. For it to work, it has to permeate every aspect of
the project. No matter what we’re doing, we should be asking our-
selves, “Is there a lighter way to do this?”
Two of the reasons most amateur aircraft are heavier than the
prototype is because of the “fly-in factor” and “gotta-have-itis:” two
virulent weight-producing mental infections. The “fly-in factor” is
the urge to have our airplanes look good on the flightline, which
often leads us to overdo things in a number of predictable areas,
chief amongst them being paint, interior, and instrument panel
(where “gotta-have-itis” kicks in). Other factors add weight, but
these three areas are where most transgressions occur and are the
easiest to control.
PAINT: THE UNDERESTIMATED WEIGHT FACTOR
The majority of spectators don’t appreciate the craftsmanship repre-
sented by things like tight, even gaps in the aileron wells or the
super-straight riveting. They are first impressed (or unimpressed) by
the finish, and the shinier the better. Plus, by the time we’ve put
several thousand hours into the project, the
very act of shooting paint on it is cathartic.
It’s the beginning of the end. And it’s hard to
stop once we start. As the gun moves across
the surface, there is raw, uncompleted air-
plane machinery ahead of it, but a gleaming,
finished, almost-ready-to-fly aircraft behind.
Wow! Things are changing so quickly! So,
why not make another pass? And another?