[StriperSniper]

if this proves true, it is a Columbia-unique problem

That would be good news. Then again, corrosion could prove to be a big problem anyway if it is from the salt air at the Cape. Who knows where else it could be.

[No Truce With Kings]

"Then again, corrosion could prove to be a big problem anyway if it is from the salt air at the Cape."

You have to read the article (which I could only excerpt). They have been extensively checking the Orbiters for corrosion. Deal is that Columbia had monal bolts screwed into aluminum. Only one where they did that. Theory is that galvanic corrosion rotted the attach points. It would have been a very slow process, but when combined with a hard whack, allowed the wing glove to slip.

Columbia had been away from the Cape for several years prior to returning from a refit. My bet is that some of the institutional memory about the differences in Orbiters disappeared during that time, so that people still there failed to realize how different the vehicle was from its sisters. Not the stuff that hits you in the face, but the little things, like monal bolts.