User Guide

Garmin G1000 Pilot’s Guide Appendices 190-00383-01 Rev. A
E-2
APPENDIX E
NOTE: TIS is unavailable at low altitudes in many
areas of the United States. This is often the case
in mountainous regions.
TIS information is collected during a single radar
sweep. Collected information is then sent through the
Mode S up-link on the next radar sweep. Thus, the sur-
veillance information is approximately five seconds old.
TIS ground station tracking software uses a prediction al-
gorithm to compensate for this delay. This algorithm uses
track history data to calculate expected intruder positions
consistent with the time of display. Occasionally, aircraft
maneuvering may cause variations in this calculation and
create slight errors on the Traffic Map Page. Such errors
affect relative bearing information and target track vector.
This tends to cause a delay in the displayed intruder infor-
mation. However, intruder distance and altitude typically
remain relatively accurate and may be used to assist in
spotting traffic.
The following are some common examples of such er
-
rors:
• When the client or intruder aircraft maneuvers
excessively 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 intercepts the client aircraft course at a shal
-
low angle (either overtaking or head-on), and
either aircraft abruptly changes course within
0.25 nautical miles, TIS may display the intruder
aircraft on the incorrect side of the client aircraft.
These are rare occurrences and are typically resolved
within a few radar sweeps once client/intruder aircraft
courses stabilize.
Pilots using TIS can provide 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. Reports should also
include the type of transponder and transponder software
version as well. Since TIS performance is monitored by
maintenance personnel, not ATC, it is suggested that mal
-
functions be reported in the following ways:
• By telephone to the nearest Flight Service Station
(FSS) facility.
• By FAA Form 8000-7, Safety Improvement Report
(Postage-paid card can be obtained at FAA FSSs,
General Aviation District Offices, Flight Standards
District Offices, and General Aviation Fixed Base
Operators).