know from personal experience that the any information that was "taken care of" expunged or otherwise can be obtained during background investigations done by the government. These are typically done internally however (federal government looking at DoD or government contracted employees (boeing, lockheed, etc) ) How deep the FBI check for the airlines is, i dunno. Post 9/11 i'm sure it's minorly indepth, but, most likely the "likely candidates" are pegged long before by TSA, and it ain't for a misdermenor.