"Eric Greenwell" wrote in message

Are airliners more likely to be coming at you from below or above? I
decided it was a toss-up, so I put my antenna on the bottom to improve
the return for ground radar (that's on an all carbon fiber glider - on
your fiberglass gliders, it might not make a significant difference).
This will aid ATC in keeping non-TCAS equipped aircraft away from me, I
hope.


Modern airliners climb out much more steeply than they descend, so you are
more likely to see an airliner coming at you from above. (unless you are
within class B/C airspace)