4
TIS Operation and Symbology
Section 1
TIS Symbology
TIS traffic is displayed on the 400/500 Series unit according to TCAS symbology, graphically displayed
on a dedicated graphical page (Traffic Page; see below), and on the moving Map Page. A Traffic Advisory
(TA) symbol appears as a solid yellow circle (or half circle on the outer range ring if the traffic is outside
the range of the dedicated Traffic Page). All other traffic is displayed as a hollow white diamond. Altitude
deviation from own aircraft altitude is displayed above the target symbol if traffic is above own aircraft
altitude, and below the symbol if they are below own aircraft altitude. Altitude trend is displayed as an
up arrow (>+500 ft/min), down arrow (<-500 ft/min), or no symbol if less than 500 ft/min rate in either
direction.
The TIS audio alert is generated whenever the
number of Traffic Advisories on the 400/500
display increases from one scan to the next. Limit-
ing Traffic Advisories only reduces the “nuisance”
alerting due to proximate aircraft. For example,
when the first Traffic Advisories appears on the
TIS display, the user is alerted audibly. So long as
a single aircraft remains on the TIS display, no
further audio alert is generated. If a second (or
more) aircraft appears on the display, a new audio
alert is sounded.
If the number of Traffic Advisories on the TIS
display decreases and then increases, a new audio
alert is sounded. The TIS audio alert is also gener-
ated whenever TIS service becomes unavailable.
The volume, pitch, and duration of the audio alert
(including the choice between a male or female
voice) is configured during installation.
The following TIS audio alerts are available:
• “Traffic” —TIS traffic alert is received.
• “Traffic Not Available” — TIS service is not
available or out of range.
Own Aircraft
‘Other’ Traffic—This symbol represents
traffic detected within the selected
display range that does not generate
a TA.
Traffic Advisory (TA)—This symbol is generated when traf-
fic meets the advisory criteria described on page 9.
Traffic Ground Track is indicated
on the 400/500 display by a
“target track vector”, a short line
displayed in 45-degree incre-
ments. This vector shows the
flight direction of the traffic.
