On the Schleicher ASH-26E, there isn't enough room above the
glareshield to allow clearance for the PowerFlarm antenna - - it's not
supposed to contact the canopy. This, and to avoid it blocking the
view or panel, required making a shelf bracket to extend aft from the
glareshield lip and also to allow the PF to mount a bit lower. This
has the added advantage of bringing the control knob a bit closer to
the pilot for easy access.

I made the bracket from aluminum with a curved portion to mate with
the underside of the glareshield, TIG welded to the bracket shelf. The
curved underside mount could be made of wood and the shelf screwed to
that if TIG welding isn't available. Links to pictures:

http://i674.photobucket.com/albums/v...021800x451.jpg

http://i674.photobucket.com/albums/v...023800x451.jpg

http://i674.photobucket.com/albums/v...024451x800.jpg

bumper