Hardware Store Airplanes
Common sense versus saving money
BY BUDD DAVISSON
THE INTERNET IS A marvelous invention and great for the immediate
exchange of information. However, there’s a dark side to it: If information is wrong or the idea is bad, just because it is on the net, it
gains credibility to those who don’t know enough to challenge it.
Read any chat group on any subject and see how many uninformed
answers to a question are posted.
A video is currently circulating in which a well-intentioned “
aircraft builder” introduces his audience to components of his
“hardware store” airplane. He explains his goal to build an airplane
using only hardware store material and get into the air as cheaply as
possible. This may be a noble goal, but it’s a flawed approach.
First, a comment: Never forget that an airplane is essentially a
very tall, very complex step ladder that gets us high enough to get
seriously hurt were it to fail. You wouldn’t climb up on your roof
using a chintzy ladder, so why would you build an airplane that way?
Now, about the hardware-store approach to aircraft construction: The entire concept of using non-aircraft parts as well as
self-designing a homebuilt aircraft and/or modifying existing
designs needs discussing. In some ways, the subject is very complex,
while in others it’s blindingly simple.
THE ARGUMENT FOR KNOWN QUALITY
When building and using aircraft parts, be it bolts, rivets, aluminum,
steel, or whatever, we know exactly what kind of performance can
be expected of those parts because we know they were manufac-
tured to meet strict standards. As soon as we get away from aircraft
material and start using non-aviation “stuff,” we’re pioneers in the
Land of Unknowns. When using those kinds of materials, the very
foundation of the aircraft will be based on
unknown strengths. Even if we’re using
information that says a Grade 5 hardware
bolt is supposed to be good for X pounds in
shear, the operative phrase is “supposed to
be.” Hardware store items quite often come
from sources that are more concerned with
maintaining a profit margin than a safety
margin, so there’s no way to know for sure
what you’re getting.