Andrew, there would be no masking due to oxidation. Anyone who has
ever looked under a microscope at a fatigue crack scenario leading to
overload failure would agree with Vaughn above, who said "accident
investigators can fairly positively tell the difference between a
structure that has failed from overstressing and one that has failed
from fatigue." Believe me, if this failure had fatigue as its initial
cause, the evidence will be very clear - the fatigue "bench marks"
won't disappear. An overload due to high Gs that blunted the fatigue
crack temporarily will also be evident.

-John


On Aug 31, 10:12 am, Andrew Corrigan
wrote:
if the limits were exceeded 10-20 years ago, the oxidization build up on
the aluminum might mask that damage. A fresh fracture would be shiny
because of the absence of oxidation.