"Dudley Henriques" wrote in message
Total replacement of a part based on an estimated failure span is good,
but
even with that in place, considering the astronomical cost of doing this,
flying these old airplanes past their projected airframe runout I think
will
always be a crapshoot.

The airframe doesn't need to be old. Cape Air has installed spar straps in
their C-402C fleet (47 C-402s) after an incident which inspired the Cessna
400 series wingspar AD.

D.