The present invention relates to a indicating system for warning airspace or threatening aircraft in aircraft collision avoidance system which provides simply and inexpensively information required for safe cruising of aircraft with respect to range of warning airspace of aircraft, positions of other...http://www.google.de/patents/US4853700?utm_source=gb-gplus-sharePatent US4853700 - Indicating system for warning airspace or threatening aircraft in aircraft collision avoidance system
