SSA petition to allow transponder to be turned off

Finbar wrote:

I'll get to my rant at the end.

First, a question: what happens if you turn off a transponder in
flight? Hypothetically, of course: would anybody notice?

Maybe. If you disappeared from a controllers screen, it would be
noticed. A TCAS equipped airliner might notice - I don't know if there
is an alert function for such an event.

Would S&R
be sent out to look?

No.


Second, a recollection: it's my recollection that ATC radar is
designed to filter out slow-moving targets.

That's primary radar, because of ground clutter problems. It would be a
most unusual situation to eliminate a transponder return. They certainly
don't do it out here in the Pacific Northwest - I've asked.

If that's the case,
transponders are only of any use to TCAD-equipped aircraft.
Apparently some ATC facilities are seeing the glider Xpdrs, so maybe
my recollection is wrong?

Yes, mainly because of a confusion between primary (skin reflection)
reflection processing and transponder return processing.


Third, evidently I now have a choice between a low-priced TCAD-type
device or a Xpdr. Having both is not an option: my panel is already
full, so stuff has to start coming out in order for me to put things
in.

Fourth, it is NOT illegal for me to turn off the TCAD-type device to
save my batteries, but it is illegal for me to turn of the Xpdr (my
home field is 33 nm from the primary airport). Score one for passive
rather than active collision avoidance. The passive device uses a lot
less power. Score two. The passive device is cheaper. Score three.

I've wondered about this, also. In addition to the advantages mentioned,
they are portable and easily moved from one aircraft to another. The Big
Question: is the pilot safer with something like the Proxalert than a
transponder? I know one glider pilot using one, so we'll have at least
on experienced opinion in a few months.

Fifth, it seems to me that an Xpdr should be fitted with a separate
battery, so that it doesn't threaten the much more important nav and
vario equipment by draining power from them.

Pilots choice: most pilots monitor their battery voltage, so they can
turn off the transponder if the voltage gets low.

Similarly the Xpdr
should not drain the battery required to relight self-launchers.

Again, pilots choice. Self-launchers typically have much larger
batteries than unpowered gliders (mine has 36 amp hours), so powering
the transponder AND still having enough to start isn't a problem at all.

Legally, I have no idea where you stand when you have a "working" Xpdr
on board, "turned on" but with a dead battery. But it's safer than
the alternative.

It's not required to be transmitting if your battery is dead.

Now my rant: bad enough that regulators make dumb laws, but worse when
SSA compounds the error. Here's why -

Regulations that impose requirements on safety equipment that isn't
even required in the first place are logically bad law (not that bad
law is particularly unusual) because they create a disincentive to the
use of safety equipment.

I think it's an oversight, rather than foolishness: airplanes ARE
required to have transponders, and this rule was written for them.
Gliders aren't required to have transponders, and when the rules were
written, they were extremely rare in gliders.

It reminds me of the reg about parachutes:
if my chute is past its repack date, it's perfectly legal for me to
use a seat cushion instead and leave the chute in my car. If I take
the chute anyway (as a seat cushion), it's illegal and I can get
busted. My chute's always properly packed (go ahead, check) but
that's not the point. Which of our regulators wants to explain to a
grieving family that the totally unnecessary fatality was caused, not
by the out-of-date parachute (which probably would have worked fine),
but by a regulation that REQUIRED LEAVING IT ON THE GROUND!

It won't ever get explained that way: the puzzled regulator will be
dumbfounded that a pilot was so clueless, that he owned a parachute and
didn't take it along. The family should also be dumbfounded, as I would
be. Get it packed if the rule bothers you, carry it if doesn't. Sheesh.
Give it to a passenger...then I think you should have packed properly.

Similarly, a regulation that requires the use of a transponder, if
fitted, when transponders are not required, is a regulation that
encourages people to... not fit transponders. Poor logic, bad law.

I believe that pilots that WANT to carry a transponder do so, and those
that want to turn if off when far from heavy traffic, also do so. No one
has been busted for turning off his transponder, and lots of pilots do.
I also believe a lot of pilots that don't want to use a transponder, use
this rule as a convenient excuse. Basically, I think, getting this
exemption is about removing this excuse. I don't think there will be
sudden surge in transponder installations by glider pilots that can't
stand to be scofflaws. Even noticed how many pilots fly near cloudbase?

This request for an exemption suffers from the same faulty logic. The
place where transponders are most important is... around the primary
airports of Class B and Class C airspace. This exemption request
removes the disincentive to carrying Xpdrs everywhere... except where
Xpdrs are important!

I think you are saying it's a good idea. I do.

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Eric Greenwell
Washington State
USA