Garmin GDL 69A Manual

A SERVICE OF

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3

TIS Operation and Symbology

Part One: Section 1

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Ofces,FlightStandardsDistrict

Ofces,andGeneralAviationFixedBasedOpera-

tions.

TIS Symbology

TIStrafc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.

 •TrafcAdvisories(TA)—Yellow

 •ProximityAdvisories(PA)—White

 •Other—White

190-00356-30 Rev C