"A Guide to Transponders in Sailplanes" - updated!

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