Several points ...

In a normal publication environment, a person has to have "chops" to be
considered for publication. In a technical article, you are expected to
have education, certificates, or experience (or all three) in order to
publish. The author of this article has a degree in "engineering
technology" and a "background" in analog and digital controls. (Hell, I
have a "background" in SR-71s -- I've seen them fly and I've read about
them -- but I certainly wouldn't write a technical article about them.)

I certainly see nothing here that qualifies the author to expound on the
practical ramifications of the FAA rules and regulations ... the education
certainly wasn't in this field, absolutely no aviation electronics design,
maintenance, or installation experience, and certainly no FAA mechanic
certifications. In the writing game, we call this not qualified to write.

The second point to make is that the author hangs his hat on the maintenance
requirements of 43.13, wherein the FAA says that you have to ... "[use] the
methods, techniques, and practices prescribed in the current manufacturer's
maintenance manual ... or other methods, techniques, and practices
acceptable to the Administrator..." The author is blissfully unaware that
90% of the avionics installed in general aviation aircraft today have never
had their maintenance manual blessed by the FAA. If the maintenance manual
has not been blessed by the FAA, standard practice in the industry is to use
best practice -- which means you have to have experience in the field to
know what best practice is. The author evidently has none.

He goes on to say that that "...unless you can get a diode...from the same
batch and brand..." that you cannot use it. Hogwash. The 1N4148 diodes in
my KX-170s were made by RCA back in 1976. RCA went out of business in the
early '80s. King certainly has no diodes from that batch left on the
shelves after 32 years. However, I can buy BILLIONS of 1N4148s to the
standard JEDEC specification that RCA met back in the '70s. The author
simply has no concept of standard parts ... like a standard PK screw that
was produced by Dinglebat Hardware for your Luscombe, and since Dinglebat
went out of business during Eisenhower and Luscombe not far behind that your
aircraft is now unairworthy with a JAN/NAS screw from Chief? Horsefeathers.

He further states that the interpretation of 21.303(b)(2) that you can in
fact make your own avionics is an "interesting interpretation" of the rules.
That "interesting interpretation" is held by a few folks in the biz
including the Office of the Chief Counsel of the FAA. Last I looked, the
Chief Counsel is the last word in the interpretation of the regulations.
(That "interesting interpretation", by the way, allowed me to donate a
kit-built transceiver to the EAA for installation in Paul's Red One VW for a
few dozen years of use. They certainly didn't seem to have a problem with
it.)

I won't go into his belief that soldering is a magic art practiced only by
the high priests of the profession, nor his belief that all required
equipment on an aircraft be TSOd. The man is simply illiterate when it
comes to avionics and the regulations regarding maintenance.

I will write a letter to the publisher later on today and post it here. You
can either sign on to what I say and send the publisher a "me too" or
disagree with me and send him the disagreement. In either case, the
publisher needs to hear from you.

Jim



"Ernest Christley" wrote in message
...
The latest Sport Aviation has an article saying that we're not allowed to
build our own avionics. According to the author, the rules say you can't
do it, but he does leave the caveat that the rules don't apply to us
homebuilders.

It's bad enough that EAA actively ignores homebuilders, but now are the
going to actively attack us with FUD?