Calibrate? Repair? Adjust?

A recent thread on what a person with an FCC license would have to do to
install/calibrate/repair/adjust radios led me to do the research that I
generally wind up doing once a year when this thread comes around again.

Let's talk about the plain old airframe mechanic ("AM") and the feller with
the FCC radiotelephone certificate ("FC").

Part 43 of the regulations specifically state that there are two categories
of "calibration" that are major repairs -- "calibration of and repair of
instruments. Calibration of radio equipment."

Note that Part 43 cleverly left OFF repair of radio equipment, while it
retained it on instruments. The FAA ain't dumb; they've got a stable of
lawyers writing this stuff. If they had MEANT to include repair of radio
equipment under major repair, they would have done so. They did not.

So let's go to Part 65 to see what AMs *are* allowed to do. 65.81a allows a
AM to "perform maintenance ... on appliances ... except ... repair to
instruments." Note again the clever mention of instruments and the
non-mention of radio equipment.

So we see that AMs with the requisite experience (again, "...the AM ... may
not perform the maintenance or repair ... unless he [sic] ... has performed
that maintenance at a prior time ...") may, in fact, repair radios. They
just can't CALIBRATE them when they are completed with the repair.

Since 14 CFR Part 1 does not define "calibrate", we have to turn to another
authority. In general, the courts have held that in the absence of a
specific definition of the controlling authority, or a generally accepted
practice in the industry, a recognized dictionary definition may be used.
Webster says that calibration is " ... to correct the graduations of a
measuring instrument (as in a thermometer). Is "alignment" calibration?
Not by this definition. Is "adjustment" calibration? No.

So let's turn our heads from radio repair to "instruments". What is an
instrument? Clearly, airspeed, gyroscopic indicators, pressure,
temperature, and those sorts of things are instruments. Indeed, Webster
comes to our help once more with a definition of instrument as "...a tool or
implement, especially one used for delicate work or for scientific or
artistic purposes." This is a particularly lousy definition for an aircraft
instrument, but let's build on it.

The specific question is whether or not a VOR head is an "instrument" in
light of the above. I can argue both ways and make good argument that it is
either a "radio" or an "instrument" depending on how we view it. So, can I
legally repair a VOR head? I argue that this is a truly gray area open to
MUCH interpretation and argument and I can sit on either side of the table
with some degree of comfort.

Now, during an install, a radio needs a couple of adjustments. Sidetone and
modulation level come to mind quickly. Since AMs can repair and align,
saying that they can't touch the installation controls is an absurdity.
However, adjustment of the modulation level CAN cause distortion and
splatter, so in this ONE ISOLATED case, I can argue for the need of a FC
certificate to make the adjustment. Otherwise, it is a pretty piece of
paper to hang on the wall.

Draw your own conclusions. It is your certificate on the line, and I'm not
going to argue with your interpretation. Nor am I going to argue with your
FSDO's interpretation. Interpretations are just like assholes, everybody
has one and most of them stink.


Jim Weir
A&P, IA
FCC 1st phone since 1959 (yes, that means I got it at 16)