Specifications

SECTION III
INSTRUMENTATION AND AVIONICS
MODEL 560
maneuvers. The following information is generated and considered by the TCAS II in making a decision as
to whether an aircraft which returns a signal constitutes a threat or not: range between your airplane and
the intruder, relative bearing of the intruder, altitude and vertical speed of the intruder( if it is reporting
altitude), and the closing rate between your aircraft and the intruder.
The TA display identifies the relative threat of each aircraft which could present a traffic conflict
(intruder), by using various symbols and colors. TCAS II also provides several appropriate synthesized
voice announcements which are used to alert to traffic and to notify them of a recommended avoidance
action. The TCAS II system is both compatible with current and planned ATC systems and operates
independently of them. It has the capability to monitor two or more TCAS II equipped aircraft by means of
their mode S transponders and to coordinate their maneuvers.
TCAS II has two types of cockpit display; the Resolution Advisory (RA) and Traffic Advisory (TA). The
RA display is incorporated into the vertical speed indicator (VSI) display on the primary flight display (PFD).
By illuminating red and green arcs around the display dial it presents the required rate or limitation of climb
or descent to avoid a possible collision. The resolution advisory (RA) is based on the expectation that the
crew will comply within 5 seconds. The system requires two and one half seconds to show an increase or
a reversal to an RA. In order for the system to generate an RA the intruder must be reporting altitude; if an
altitude is not bearing reported the advisory will be limited to a TA. The TA display shows the intruding
airplane's relative position and altitude, with a trend arrow to indicate if it is climbing or descending at
greater than 500 feet per minute. This display is provided at the bottom area of the MFD, which is reserved
for TCAS presentation when TCAS is selected for display.
Normally a TA will precede an RA by 15 seconds, if an RA is going to ensue from the computation of
closure rate, heading, rate-of-climb/descent etc., of the intruder. Depending upon altitude, the system will
present a traffic alert display, accompanied by an aural “TRAFFIC, TRAFFIC”, when the time to the closest
point of approach is between 20 and 48 seconds. The crew should attempt to gain visual contact with the
intruder and be prepared to maneuver. The crew should take no evasive action based solely on the TCAS
II traffic display.
TCAS II can track as many as 45 aircraft at one time and display up to 30 of them. It can coordinate a
resolution advisory for as many as three intruders at one time. The advisories are always generated
considering the least required amount of deviation from the flight while providing a safe vertical separation.
TCAS II does not replace ATC procedures and the existing “see and avoid” concept, however, if ATC
communications are temporarily lost, TCAS II adds a significant backup capability for collision avoidance,
and can also enhance safety of flight in crowded terminal areas, under both VFR and IFR conditions.
For specific operating procedures, consult the Bendix/King TCAS II Traffic Alert and Collision
Avoidance System Pilot’s Guide, 006-18201-0000, dated April 1999 or latest Revision.
I 3-72 Configuration AA 56OMB-01