Smarter Collision Avoidance

Keith Button of Aerospace America reports on the interest in the ACAS Xa (Airborne Collision and Avoidance System), a replacement for the TCAS (Traffic Alert and Collision Avoidance System), which has been the industry standard used by aircraft to avoid other aircraft. He says, "It's [ACAS Xa] supposed to outperform TCAS 2 on safety and reduce unneeded alerts by adopting a more modern computing approach and by taking advantage of GPS position reports in the messages sent from the Automatic Dependent Surveillance-Broadcast transponders that planes are starting to carry... In contrast to [the] conventional computing method, developers of ACAS Xa at the Johns Hopkins University Applied Physics Laboratory in Maryland and MIT Lincoln Laboratory outside Boston capitalized on concepts within the field of artificial intelligence. The software directs the computer to make decisions based on probability distributions for possible outcomes at each step in a time sequence, because the exact circumstances for those decisions can be only partially known ahead of time."