Bob,

 

The outside extension keeps weather from fouling the seal or leaking in while the plane is parked outside.  The inside extension is necessary to prevent distortion of the canopy (especially the forward part of the side) caused by low pressure in the cockpit during flight and possible forces created by the gas spring.

 

Grayhawk

 

I am in the process of revising and finally finishing my 320/360 forward hinged canopy.  I am interested in what type seal works best, lasts the longest, etc.  Do you have a glass lip on the canopy that extends down over both sides of the longerons, or just the inside or just the outside? 

Bob Mitchell

L-320 N56SH