Improving Tis; Tis Symbology - Garmin GDL 69A Pilot's Manual Addendum

and avoid." Some of the more common examples of
these errors follow:
• When client or intruder aircraft maneuvers exces-
sively or abruptly, the tracking algorithm may
report incorrect horizontal position until the
maneuvering aircraft stabilizes.
• When a rapidly closing intruder is on a course that
crosses the client aircraft course at a shallow angle
(either overtaking or head on) and either aircraft
abruptly changes course within ¼ NM, TIS may
display the intruder on the opposite side of the
client than it actually is.
These are relatively rare occurrences and will
be corrected in a few radar scans once the course
has stabilized.

Improving TIS

Users of TIS can render valuable assistance in
the correction of malfunctions by reporting their
observations of undesirable performance. Reporters
should identify the time of observation, location, type
and identity of aircraft, and describe the condition
observed; the type of transponder processor and soft-
ware in use can also be useful information. Since TIS
performance is monitored by maintenance personnel
other than ATC, it is suggested that malfunctions be
reported in the following ways:
• By telephone to the nearest Flight Service Station
(FSS) facility.
• By FAA Form 8000-7, Safety Improvement Report,
a postage-paid card designed for this purpose.
These cards may be obtained at FAA FSSs, General
Aviation District Offices, Flight Standards District
Offices, and General Aviation Fixed Based Opera-
tions.

TIS Symbology

TIS traffic is displayed on the 400W/500W 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 dia-
mond. 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.
• Traffic Advisories (TA)—Yellow
• Proximity Advisories (PA)—White
• Other—White
190-00356-30 Rev C
Part One: Section 1
TIS Operation and Symbology
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