ProfChrisReed asked:
"This is a naive but genuine question for non-glider pilots who fly IMC in class G:
Can you be sure that you are aware of other pilots doing the same? In other words, if another pilot is also flying IMC but speaking to a different ATC service, would you receive that information?
And as a supplementary, do all non-glider pilots flying IMC in class G inform ATC of their activities, or are there some who merely monitor one or more frequencies without transmitting?"
My responses, in order:
1.) Not necessarily BUT if he is operating IFR he should carry the legally mandated minimum equipment, which includes a transponder. If he requests a radar service from ATC he will be required to squawk a code for identification. We carry TCAS to help identify other aircraft, whether on the same frequency or not but transponding. Despite costing more than some gliders (!) it is by no means infallible. Aircraft not transponding don't appear on TCAS. The LARS system is there and pilots are strongly encouraged to use it but there are some gaps in coverage.
2.) Impossible to answer. Airmanship / survival instinct makes me obtain an appropriate ATC service where available, preferably a RIS.