Operating Instructions
TCAS791
2-14
Pilot’s Guide
and one of the shorter display ranges. The procedures for selecting the
altitude display mode and display range are the same as those listed
previously under preflight instructions.
Observe the Display
Monitor the activity of any traffic displayed. Keep in mind the follow-
ing points when watching traffic on the display:
• Traffic Prioritizing – The TCAS791 can track up to 35 intruder
aircraft simultaneously, but to reduce clutter, it displays only the 8
most threatening aircraft of those tracked.
• Traffic symbols may occasionally disappear and reappear due to
traffic prioritizing (see above), interference limiting, antenna shield-
ing, or reception of low power transponders (see chapter 3).
• Ground Target Filtering – If your aircraft has a compatible radio
altimeter connected to the TCAS791, TAs, PAs, and other traffic
symbols will not be issued for traffic detected under 380 ft AGL
when your aircraft is below 1,700 ft AGL.
• On some alternate displays, other traffic symbols will disappear
when a TA occurs and will reappear (if still in range) once the TA
goes away.
Figure 2-10. Altitude Display Modes
+2700 ft
–2700 ft
+9000 ft
Intruder Aircraft
–9000 ft
Belo
w
Displa
y M
ode (Look Do
wn)
Abo
ve
Displa
y M
ode (Look Up)
Nor
m
al
Displ.
M
ode
0 ft
Max. Display Range
Max. Display Range
Own Aircraft
