Mike Schumann wrote:
"Most gliders aren't a hazard to airliners or other controlled traffic"?????
What is the basis for that claim? There's IFR traffic everywhere. The
stuff you see isn't the threat, it's the targets you don't. Anyone who
thinks that they are immune from mid-airs because of where they fly is just
rolling the dice.

"Most" was too strong, so let me replace that with "At least half the
gliders aren't a hazard...". It is a guess, but a reasonable one, I
think. By "hazard", I mean that an IFR pilot might actually pause for a
seconds before deciding to make the flight anyway, once he is informed
about where the glider is. In other words, the risk to IFR traffic is so
low, no one is worried about it.

That situation describes a lot of training operations, ride operations,
and even cross-country flights. The risk can be low for several reasons:

*there aren't any airliners going through the area when the gliders are
operating, and very few other IFR flights.
*Or, operations are conducted in a manner where installing a transponder
wouldn't change the risk significantly. For example, where procedures
such as contact with the tower at the nearby field ensure separation.

Yes, the odds are different in different places, but the
risk is 0 everywhere.

There are many places without airliners or IFR traffic. Lots and lots of
small airfields, even municipal airports, simply don't attract that kind
of traffic. I think it's important to recognize that not every airfield
is not just outside a Class B airspace.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

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

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