http://abclocal.go.com/ktrk/story?se...cal&id=7848683

Authorities tell ABC News the incident is not uncommon, but how often it occurs is a closely guarded government secret. Experts say every year since the September 11 attacks, federal agencies have conducted random, covert tests of airport security.

A person briefed on the latest tests tells ABC News the failure rate approaches 70 percent at some major airports. Two weeks ago, TSA's new director said every test gun, bomb part or knife got past screeners at some airports.