Texas-based Aircraft Security and Alert Systems is promoting a tamper evident tape as a cheap and "residue-free method of absolutely determining whether an attempt has been made to gain entry into an aircraft or any of its compartments." TED is a multi-layered tape that's placed across door seams when securing an aircraft after flight. An attempt to gain entry will break layers in the tape. Operators "will find it comforting to know that some relatively low-cost technologies can provide a high level of security," said company president Jim Jetton.