>Photo  Apex Departing Slot clearly shows where the missing piece of the
apex

>seal bent over the straight edge of its slot when it departed. Apparently

>when it left the clearance was getting less and the departing edge was

>apparently caught between the lip of the slot and the rotor housing forming

>a flatten corner.

>

Ed,

How well does the position of the break line up with your exhaust port?  Are
there any tiny chips near the break that look like they may have been around
a while?  

I'm thinking of the possibility of a piece of debris chipping the seal in
the vicinity of where it flexes as it crosses over the exhaust hole.  Stress
riser, being the unpredicable ^%&# they are, will always give out just as
you cross the limit of not being able to glide home.