At NBAA’04 last month 3M Aerospace introduced the 900AST (advance  systems tester), a handheld unit used for checking for faults in avionics wiring. The tester can pinpoint open, short and intermittent faults, providing maintenance technicians the location of the problem on the unit’s display. The 900AST includes an infrared port for uploading test results to a PC and built-in internal help menus.