On 18-Dec-2007, Jay Honeck wrote:

Agreed. Boeing must've built the BUFF hell-bent for strength, since
I've never heard about *any* fatigue issues in the fleet.
--
Jay Honeck

I once saw a drawing showing with shading of all the skin and structure that
has been replaced on the B-52 fleet over the years, and as I recall it
involved most of the exterior. Very little of the skin is original, if
memory serves me correctly. I think they replaced panels and structure
before fatigue became an issue.
On this topic, did ya'll know the entire USAF F-15 fleet is grounded with
the exception of the F-15Es? There was a recent crash of a Missouri ANG
Eagle in which the nose section snapped off in flight just behind the
cockpit. The pilot ejected safely. They've since identified other cracks
in the fuselage longerons of the crashed aircraft. They've found similar
fatigue cracks in eight other Eagles during four separate fleet-wide
inspections, and thet've decided not to lift the grounding order until
they are sure they've identified all of the potential areas for fatigue
cracks.
Scott Wilson