Specifications

SECTION III
MODEL 560 INSTRUMENTATION AND AVIONICS
TCAS 1 has two sensitivity levels; SL A and SL B. SL A is invoked when the airplane is below 2000
feet AGL, based on radio altimeter altitude. SL B is all other flight conditions. SL A is less sensitive, to
preclude nuisance advisories in the area of airports and terminal areas, where the traffic density is highest,
and airspeed is usually slower.
There are three modes of altitude display limits: ABOVE, NORMAL, and BELOW. ABOVE mode
displays traffic that is between 8700 feet above and 2700 feet below your own airplane. ABOVE is typically
used during the climb phase of flight. NORMAL mode displays traffic that is between 2700 feet above and
2700 feet below your own airplane, and is normally used for cruise flight. BELOW mode displays traffic that
is between 2700 feet above and 8700 feet below your airplane. BELOW is normally used during the
descent phase of flight.
If the TCAS system is unable to locate the azimuth of another aircraft, a NO BEARING message will
appear on the screen when the system computes that the intruder is close enough to become a threat.
If the intruder aircraft is non-altitude reporting the TCAS will report only the range and bearing. It can
issue a traffic advisory (TA) based upon distance and direction of flight. TCAS assumes that non-altitude
reporting traffic is the same altitude as your own airplane.
CAUTION
THE CREW MUST NOT INITIATE EVASIVE MANEUVERS USING INFORMATION
FROM THE TRAFFIC DISPLAY ONLY. THE TRAFFIC DISPLAY IS INTENDED TO
ASSIST IN VISUALLY LOCATING TRAFFIC. THE TRAFFIC DISPLAY LACKS THE
RESOLUTION NECESSARY FOR USE IN EVASIVE MANEUVERING.
It is possible to see an aircraft flying the same course and direction as your own airplane, yet TCAS
may not consider it a threat. TCAS calculates the closure rate of the intruder, and derives the time to the
closest point of approach (CPA). If there is no closure rate, no advisory will be issued, unless the intruder
is very close (within approximately 0.2 mile). However, traffic at the same altitude very far ahead (about 10
miles) may be shown as a TA by TCAS because of a very rapid closure rate.
For specific operating procedures, consult the Bendix/King TCAS I Collision Avoidance System Pilot’s
Guide, 006-08746, Rev. 1 dated August 1993 or latest Revision.
TCAS II
TCAS II detects and tracks aircraft in the vicinity of your own airplane. It interrogates the transponders
of other aircraft and analyzes the signals to determine range and bearing, and relative altitude if it is being
reported. It then issues visual and aural advisories so the crew may perform appropriate vertical avoidance
!!!
Figure 3-35. TCAS 1 Control Panel
I 56OMB-01 Configuration AA 3-71