"A Guide to Transponders in Sailplanes" - updated!

On Feb 14, 2:12 am, user <u...@newsgro> wrote:
> You say to mount the aerial under your thigh.... not a good idea for a
> 200 watt transmitter cause it will cook your balls. Most Transponders
> have a minimum distance allowed from people, like 3 feet. Please check
> this out !

I mentioned some pilots have mounted it in that position. I don't
think I said to do it that way. Can you tell me the page and paragraph
that leads you to think I recommended it? Perhaps its not written
clearly.

And to reiterate, it's not a "200 watt transmitter". The peak power of
the pulses is 200 watt, but it's only about a 5 watt max transmitter,
as the pulses are short.

"Eric Greenwell" <engreenwell@> wrote in message
news:a120ae25-1464-458d-8070-44cae257a253@e25g2000prg..com...
>
> And to reiterate, it's not a "200 watt transmitter". The peak power of
> the pulses is 200 watt, but it's only about a 5 watt max transmitter,
> as the pulses are short.


I know you are talking about peak power vs average power. However, even
though pulse width is narrow, and thus the average radiation from a 175 or
250 watt transponder might be on the order of 5 watts, I'm not sure the
radiation exposure should be equated to just the low average power.

Consider a single high powered pulse as being one .22 rifle bullet. The
bullet might have on the order of 100 ft pounds of energy and would
obviously do considerable tissue damage. Compare that to several hundred
BB's from a low powered air rifle, the combined energy of which equals the
energy of that one .22 bullet. Same total energy, far less damage. The point
I'm trying to make is that pulsed high energy may well do more tissue damage
than the same total amount of low level energy delivered over a longer time
frame.

I want that transponder antenna installed away from me.

bumper

On Feb 14, 9:59 pm, Mike the Strike <Stringm...@msn.com> wrote:
> On Feb 14, 9:42 pm, Mike the Strike <Stringm...@msn.com> wrote:
> We have had a collision between an aircraft and a sailplane whose
> transponder was turned off "to save the batteries", so this isn't just
> a theoretical problem.

The report I read said the transponder was not turned on because the
transponder installation was not certified. Did you hear different?

It is illegal to operate a transponder without current certification.

Andy

On Feb 14, 8:42 pm, Mike the Strike <Stringm...@msn.com> wrote:
> > > Also.....consider, a Transponder equipped aircraft is also REQUIRED to have
> > > the transponder ON and reporting at all times from wheels up to wheels
> > > down......not just as I have heard many glider pilots saying they "only use"
> > > the transponder when they are flying at or near areas of high traffic....
> > > think about this....
>
> > A lot of us have thought about this, including people in the FAA, and
> > decided it's a lot better to have a transponder on in areas that need
> > it, instead of risking a dead battery (meaning NO radio or
> > transponder) later in the flight, or discouraging pilots with marginal
> > batteries from installing a transponder. I covered this in the the
> > "Guide". Take a look at that section and see if it promotes flight
> > safety better than strict adherence to the "always on" rule; also,
> > take a look at the "Why doesn't the SSA ..." section that addresses
> > the FAA's official position.
>
> This argument seems rather like deciding to put your seat belt on in a
> car just before you have a crash!

And that is the only time you need to have it on - it has no value at
any other time.

Actually, the argument is more about encouraging people to install the
seat belt in the first place, and hope they will use it when it
matters.
>
> Anyway, this rule isn't an option, it is mandatory. If you have a
> transponder the regs say it MUST be on while you are flying. No pilot
> discretion here.

The nuance here is that we are not required to have transponders
installed, so it seems reasonable to argue that pilot A, who turns on
the transponder for some of the flight, is improving safety more than
pilot B, who doesn't install a transponder. Yes, pilot A is operating
contrary to the regulations and pilot B isn't, but which one is making
flight safer? Our SSA representatives that discuss these things with
the FAA say the FAA much prefers pilot A.

Mike Schumann wrote:
> I find it difficult to believe that adding a battery would cost $1,000. I
> would think that this could be included as part of the installation of the
> transponder.

FWIW, we had a great deal of trouble with battery failures using a Terra
TRT250D transponder (nearly twice the power consumption of a Becker,
which wasn't then available in the US) in our Duo with the standard
installation of two 7ah batteries. We would get about 3 to 4 hours out
of each, failing to switch at the proper time would result in a useless
battery after a few cycles. We wanted to switch to 12ah batteries, but
there is essentially no room in a Duo for anything that size in an
accessible spot, if we still wanted to continue to carry drinking water,
survival kits, and/or jackets (this isn't the only glider with this
problem). So, we had the local shop reshape the molded battery wells in
the floor to accommodate the larger batteries. This involved cutting
out the existing wells, molding new larger ones, glassing them back in,
and painting. When all was said and done, it cost well over $1000, but
it solved the problem...

Marc