After the tragic collision between a Russian Tu-154 and a DHL cargo Boeing 757 at 35,400 ft over southern Germany on July 1, AIN questioned whether regulations, or any other body of accepted procedures, clearly state which command took precedence–that of the onboard traffic alert collision avoidance system (TCAS) or that of the human controller.
Portable Collision Avoidance System
The unit, which plugs into an AC power receptacle, is about the size of an automotive radar detector and contains an integral antenna and small display. XRX tracks up to 10 aircraft at a time and displays the top three threats. Unlike TIS-based systems, which rely on ground-based radar, XRX works independently of mode-C interrogation, displaying quadrant bearing information, relative altitude and range.