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MAINTENANCE MANUAL
CAS-100 COLLISION AVOIDANCE SYSTEM
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(2) Tracking Function
• Tracks maximum 45 combined Mode S and Mode A/C transponder equipped intruder
aircraft. Tracks range of intruder aircraft. Tracks intruder relative bearing if tracking is
occurring on a directional antenna. Tracks intruder relative altitude if intruder is
reporting altitude.
• Calculates estimated intruder relative position.
• Calculates closing range rate.
• Calculates altitude change rate if intruder is reporting altitude.
• Estimates miss distance.
NOTE:
Surveillance and tracking functions are performed by listening for Mode S
squitters, Mode S and ATCRBS Mode C interrogation transmissions, and Mode
S and ATCRBS Mode C reply receptions on the top and bottom TCAS antennas.
(3) Threat Potential Evaluation Function
• Determines the threat potential of intruder aircraft based on results using tracking data.
• Categorizes intruders as RAs, TAs, proximities, or nonthreats.
(4) Collision Avoidance Computation and Resolution Advisory Display Function
When an RA threat aircraft is present, TCAS finds the applicable vertical maneuvering
for own aircraft to get or keep a safe miss distance between own aircraft and intruder
aircraft. This maneuvering is done while creating the least change from own aircraft
vertical rate. TCAS communicates the recommended maneuver to the pilot with a
resolution advisory display on the TA/VSI or RA/VSI units.
(5) Traffic Advisory Display Function
Gives a display of RA, TA, proximity, or nonthreat category traffic that are present in the
adjacent airspace. The traffic display shows the position and the threat potential of
intruder aircraft which alerts the flight crew to potentially dangerous conditions.
Depending on the aircraft equipment, the traffic display can come into view on a TA/VSI
unit or an optional PPI or dedicated TCAS display unit.
(6) Aural Alert Function
Gives voice message advisory alerts on the cockpit audio system.
