AUGUST 2019 FLYINGMAG.COM | 65I FINALLY NOTICED THE SMALL PRINT
AT THE BOTTOM OF SOME FAA PAGE OR
OTHER—I CAN’T EVEN FIND IT NOW—
THAT SAID, IN EFFECT, “IF YOU HAVE AN
UNSATISFACTORY PAPR, CONTACT US
BEFORE CONSULTING A REPAIR SHOP.”
As far as the stealing part is
concerned, it’s actually harder to
remove than it is to install. And at
any rate, it’s worthless to anyone
else because to program it with the
ID of another airplane, you have to
know its Wi-Fi password.
To answer the other question, I
located the patent application online.
It turns out—I hope I have this
right—that to discriminate between
“ own-ship” squawks and those of
other nearby airplanes, it moni-
tors the wire that delivers power to
the taillight. This wire acts as an
antenna, registering a faint echo of
your own squawk, which the device
isolates from the general noise. Other
airplanes’ squawks are too faint to
register. Very neat.
But would it work?
The way you find out is to make a
30-minute flight in ADS-B airspace.
You then go to an FA A website and
fill out a very brief “Public ADS-B
Performance Report Request,” pro-
viding some information about your
system and your assessment flight.
Within a few minutes, an email comes
to you with a multipage public ADS-B
performance report. Functions that
are outside acceptable limits are
highlighted in red.
I had some red.
The next step was to go over to Van
Nuys Airport (where my transpon-
der would respond to interrogations
while on the ground), adjust a param-
eter called “sensitivity” and repeat
the test.
My next PAPR had less red, but it
was not red-free.
A second trip to Van Nuys. A third
PAPR. No change.
I spoke with a radio shop. The
owner was of the opinion that uAvi-
onix was optimistic in claiming that
the device would work with any tran-
sponder. He thought the problem was
undoubtedly my 45-year-old Narco
AT-50A and offered to sell me an
AT-150—old transponders are a drug
on the market now that lots of people
are putting in new ADS-B ones—for
$250. It would just slide into the same
rack with no hassle at all.
I bought it and slid it in. On my
first takeoff, the tower saw only a
primary return.
I sent back the AT-150. Now the
radio guy offered me a Garmin 327,
which he said was bound to work
fine; so I gave him another $250.
This was beginning to smart. For the
Garmin, I had to make a new wireloom and install a new rack. At this
point, I had wandered a long way from
plug-and-play, but, to tell the truth,
the installation was kind of fun.
I got a new PAPR. To my dismay, it
was identical to the AT-50A one.
I finally noticed the small print at
the bottom of some FAA page or oth-
er—I can’t even find it now—that said,
in effect, “If you have an unsatisfac-
tory PAPR, contact us before consult-
ing a repair shop.” I did so and received
this prompt and welcome reply:
“It appears the error is only
because of loss of ADS-B coverage
due to low altitude, and your system
is fine.”
So, Melmoth 2 had at last emerged
from the Dark Ages of radar into the
golden sunshine of NextGen.
I will never know whether the
transponder change was even neces-
sary; the system may have been just
as fine with the AT-50A, which now
sits forlorn on a shelf in my office, no
doubt reminiscing about the time it
sent a single heroic squawk 120 nm to
Shemya, Alaska, after we had drifted
off course in the mid-Pacific.
There were some downsides to my
choice of which I was unaware when
I made it. Because the tailBeacon is
non-TSO, it did not qualify for the
FA A’s $500 rebate. It is also a uni-
versal access transceiver rather
than 1090ES, so it’s no good above18,000 feet or outside the United
States. These could prove to be
significant constraints; the air-
plane is turbocharged, and Mexico,
for instance, has the same ADS-B
requirements as we do.
Because I avoided even thinking
about ADS-B Out for so long, I onlynow became aware of its sociopolitical
aspects. One person sees it as user
fees’ foot in the door. Another worries
that any infraction, however minor
and inadvertent, will be recorded
by a computer somewhere. I think
that concern is unnecessarily dire.
Although it can be readily proven from
your times through gates on a toll road
that you have been speeding, you don’t
get computer-generated tickets. When
the original transponder requirement
came out, some alarmists saw it as the
FA A trampling on the last remaining
shred of our freedoms.
Generally speaking, there are the
same concerns about privacy that
people have about cellphones track-
ing their every move. The good thing
about UAT devices, however, is that
they can operate in “anonymous”
mode, in which the airplane’s ID is
disguised. It becomes, in effect, just
a Mode C airplane squawking 1200.
Flights in anonymous mode are not
eligible for ATC services—other than
takeoff from a controlled airport—
but anonymous mode is automatically
canceled if you select a code other
than 1200.
It feels a little sleazy to be skulking
around in the electronic equivalent
of a fake beard, but I guess it’s bet-
ter than everyone and his brother
finding out what a rotten job I do of
maintaining an exact altitude.