Garmin 396 Guida Utente

TIS is NOT intended to be used as a collision avoidance system 

and does not relieve the pilot responsibility to “see and avoid” 

other aircraft. TIS should not be used for avoidance maneuvers 

during IMC or other times when there is no visual contact with the 

intruder aircraft. TIS is intended only to assist in visual acquisition 

of other aircraft in VMC. No recommended avoidance maneuvers 

are provided for, nor authorized, as a direct result of a TIS display or 

TIS advisory.
While TIS is a useful aid to visual traffic avoidance, it has some 

system limitations that must be fully understood to ensure proper 

use. Many of these limitations are inherent in secondary radar 

surveillance. In other words, the information provided by TIS will 

be no better than that provided to ATC. TIS only shows aircraft with 

operating transponders installed. 
TIS relies on surveillance of the Mode S radar, which is a 

“secondary surveillance” radar similar to the ATCRBS. TIS 

operation may be intermittent during turns or other maneuvering. 

TIS is dependent on two-way, “line-of-sight” communications 

between the aircraft and the Mode S radar.

Whenever the structure of the client aircraft comes between the 

transponder antenna (usually located on the underside of the aircraft) 

and the ground-based radar antenna, the signal may be temporarily 

interrupted. Other limitations and anomalies associated with TIS are 

described in the AIM, Section 1-3-5. Refer to 

information.

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GPSMAP 396 Pilot’s Guide

TIS > 

TIS L

IMITATIONS