hello all!
in Germany it is
required to have your transponder on 0022 above 5000 ft MSL or 3500 GND for motorized aircraft (gliders exempt), below that 0021 is only recommended. I remember a student telling me that another instrutor told him "leave the transponder off, they (i.e. ATC) don't need to see what we're doing".
not a good example for a student IMHO!
I flew with another student on a XC... we stayed below 5000 ft but had the transponder on 0021 C as recommended and listened into FIS, not announcing ourselves, but listening in gave us any info we needed (we were outside any type of restricted areas, of course). There was quite a bit of military traffic around. At one point we heard ATC tell a military jet about "unidentified traffic at about suchandsuch altitude flying, flying NW at suchandsuch o'clock position"... the jet replied "in sight"... my student looked at me with a big eyed look and asked "did they mean us?" I calmly affirmed. That is one student that will always turn on his transponder I'm sure!
Westy