Are you asking about a motorglider..Grob 109 or similar, or a self launching
sailplane?
If the former, there's some good info in the Grob 109 yahoo group

"Soartech" wrote in message
...

You would have to install a new mike jack with a set of break-on-insertion
contacts and run the boom mike through those contacts. Try something like a
Switchcraft L12B available at Mouser or Digikey.