TCAS was developed in response to mid-air collisions between aircraft. In the 1970s, an alternative airborne system called BCAS was proposed that used transponders to supplement radar information. This system was later renamed to TCAS. By the 1990s, Congress mandated that all commercial aircraft operating in the US must have TCAS installed. TCAS assists pilots in preventing collisions by interrogating other aircraft's transponders to determine their flight paths and identifies potential threats.

1. TCAS

2. TCAS HISTORY
• 1956 - Two planes collided over the Grand Canyon
• 1974 - Alternative airborne version using transponders
• Beacon-Based Collision Avoidance System (BCAS)
• 1981 - The FAA chose to pursue the onboard design
• BCAS was renamed TCAS
• 1986 - While TCAS still in development, collision occurred
• 1993 - Congress mandate all carrier acft operating w/in US
• 1997 - Final major change to the TCAS logic, version 7

3. GENERAL IDEAS
 Increasing aircraft collision.
 Supplement radar information
system early 70s.
 It bases its operation on the
signals emitted by the
transponder.

4. GENERAL IDEAS
 Assists the pilot in preventing midair
collisions.
 The system interrogates the transponders
of other aircraft using his responses to
determine the flight paths of each.
 With this information it discriminates
between traffic that may be at risk and
those without.

6. Traffic Advisory
• A TA indicates that an aircraft
• is a potential threat
• RA may be necessary w/in, approx, the next 25 sec
• most commonly displayed as a yellow circle

7. Resolution Advisory
• An RA indicates that an aircraft
• Is a threat
• displayed as a red square
• accompanied by a recommended vertical maneuver.