Federal undercover investigators who sneaked prohibited items with alarming ease past Homeland Security Department airport screeners have also smuggled simulated bombs and weapons aboard planes during tests as far back as September 2002, U.S. audits show. Results of the latest undercover test are classified, but members of Congress said mock explosives, weapons and other prohibited items went unnoticed in 67 out of 70 tries at Transportation Security Administration airport checkpoints. Rep.