"A Guide to Transponders in Sailplanes" - updated!

Darryl Ramm wrote:


I suspect it is to prevent thinking like "I'll just turn this little
box off and bust whatever FAR I feel like cuz noboby can see me" (even
if ATC can see you as a primary on radar).

And "turning the little box off" is more deleterious to safety, or
enforcement, than no installation at all?



Seems a perfectly fine
requirement for a powered aircraft and I'd be surprised if gliders
were front and center in any thinking about this requirement.


Agreed. Gliders are not often a concern. So why restrict gliders?



...the FAA seems to be showing perfect restraint in not
enforcing the thing you seemed concerned about, and therefore helping
encourage use of transponders in sailplanes.


I'm sure there are several practical considerations involved, including
the difficulty of enforcement. But when an agency "chooses" to enforce
or not enforce a particular reg, alarm bells ought to go off everywhere.
I don't dispute there are mostly rational people in the FAA. My dealings
with them have always been satisfactory. The problem is the process,
which does not seem very rational. The production of incompletely
structured, yet overly complex, regulations is pervasive in aviation, as
elsewhere.



For many people flying in high-traffic areas, and that's a lot more
than just around Reno, it is not outrageous to expect them to install
batteries (and/or possibly solar panels at significantly higher cost)
so they can operate transponders thought quite long flights. So there
is no need to turn off those transponders - and in those areas that
*is* a safety of flight issue.


It is reasonable that a transponder installation will include adequate
power to insure required operation of the equipment, when the
requirement is based on traffic management. It is not reasonable to
require that the installation will support operation in circumstances
where traffic management by ATC is not an issue. Decisions regarding use
of the transponder in circumstances not involving traffic separation or
National Security concerns should be left to the operator.

Non-enforcement is a non-reason. That can change overnight. If a rule is
illogical, or realistically unenforceable, or counter-productive, then
it ought not be a rule.



Jack

J a c k wrote:

Seems a perfectly fine
requirement for a powered aircraft and I'd be surprised if gliders
were front and center in any thinking about this requirement.


Agreed. Gliders are not often a concern. So why restrict gliders?

Here's an excerpt from my "Guide to transponders in sailplanes" that
describes the current situation:

Summarizing what an SSA director involved with SSA/FAA matters told me:

What we spent years doing was trying to get the FAA to agree that we could turn them
[transponders] off if necessary. The irony here is that we are asking the FAA to legalize is what the
pilots are already doing, and the FAA knows they are doing it.

The conversation basically went something like this...

SSA: "The pilots are turning them off to save battery power and keep the radio
operating".
FAA: "Yeah, we know".
SSA: "We think they should be allowed to do it in remote areas".
FAA: "We agree".
SSA: "How do we legalize this?"
FAA: "File a petition".

So the FAA wanted us to submit a petition for "legal" reasons, and we did (Jan. 2004). We have
glider pilots throughout the FAA building in DC and they already know all about low power
transponders. We know that ATC has even told pilots to leave them on and turn the radio off - we all
agree that's nuts, but it's what the rule says. They also have told us that the day after a mid-air
between a glider and a commercial transport, we will lose our exemption. What we're trying to do is
get agreed to procedures and policies in place before that day happens.
Currently (Oct. 2007), the petition is still awaiting action from the FAA.

This excerpt suggests a pragmatic approach, given the current situation
is likely to persist for years:

Can I turn the transponder off to save the battery?

FAR 91.215(c) requires aircraft with a properly functioning transponder to operate it at all times while
flying. We all know that some transponder-equipped sailplane owners conserve their battery by using
the transponder only in areas where traffic is heaviest, and there have been no official reprimands so far.
This is better than having a dead battery later on in the flight, when a transponder might be most useful,
and being without a radio and other instruments.

I have never read a description of the reasoning leading up to the
"always on" rule. Perhaps someone does, or can supply references to an
explanation.
--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Guide to Transponders in Sailplanes"
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more
* http://tinyurl.com/y739x4

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org