It was inop at the time:

"The jet’s transponder, which usually helps locate the aircraft, was not working “for some reason that we haven’t yet determined,” said Jeremy Huggins, a spokesman at Joint Base Charleston. “So that’s why we put out the public request for help.”

Oh, someone sure is going to have to answer some tough questions. If not in purely military airspace, or combat operations, military aircraft have to be airworthy according to civil standards.

That being said, no casualties, loosing a stealth fighter is somewhat funny.

If it was a two-ship, could have been only the lead had their transponder on. Keeps the ATC traffic alert systems a little happier.

Thanks, haven't yet read the article through when I commented, stupid of me.