Communication and navigation equipment is literally of vital importance in the world of commercial and military aviation. NAV/COMM on-board equipment and ground stations must be systematically checked using specific measuring equipment. TACAN, Transponder, Interrogator, DME and ADS-B are terms that are commonly heard. CN Rood supplies compact IFR 4000 testing sets and IFR 6000 Transponder / DME testing sets. In addition, there is VHF communications equipment as well as altimeters and GPS testing sets for exact positioning of aircraft in relation to each other and the ground beacons. CN Rood supplies the ALT-8000, a portable FMCW/Pulse Radio Altimeter testing set, and the GPSG‑1000, a portable testing set for GPS/GALILEO receivers.