If you have a tip up canopy then just behind the rear window on the top. For best performance it is required to have the top and bottom antenna directly above one another.
This is mostly the easiest part. Findi g a home for the conrtol box and running the antenna cable maybe the biggest problem. I belive the the cable must have a minimum length.
On our work aircraft the Sikorsky S76 we have taken up that length in the belly of the aircraft.
Ours are the TAS610 and we love them. Great bit of kit.
