Garmin MX20 - Manual (Page 57)


Detailed Operation
ADS-B Traffic
TIS-B Limitations
1. TIS-B is NOT intended to be used as a collision avoidance system and does not relieve the pilot’s
responsibility to “see and avoid” other aircraft. TIS-B shall not be used for avoidance maneuvers
during times when there is no visual contact with the aircraft. TIS-B is intended only to assist in
the visual acquisition of other aircraft. No avoidance maneuvers are provided for, nor autho-
rized, as a direct result of a tIS-B target being displayed in the cockpit.
2. While TIS-B is a useful aid to visual traffic avoidance, its inherent system limitations must be
understood to ensure proper use.
(a) A pilot may receive an intermittent TIS-B target of their own aircraft, typically when maneu-
vering (e.g., climbing turn) due to the radar not tracking the aircraft as quickly as ADS-B.
(b) The ADS-B-to-radar association process within the ground system may at times have difficulty
correlating an ADS-B report with corresponding radar returns from the same aircraft. When this
happens the pilot will see duplicate traffic symbols (i.e., “TIS-B shadows”) on the cockpit display.
(c) Updates of TIS-B traffic reports will occur less often than ADS-B traffic updates. (TIS-B posi-
tion updates will occur approximately once every 3-13 seconds depending on the radar coverage.
In comparison, the update rate for ADS-B is nominally once per second).
(d) The TIS-B system only detects and uplinks data pertaining to transponder equipped aircraft.
Aircraft without a transponder will not be displayed as a TIS-B target. Assume that there are more
aircraft in the vicinity of your aircraft.
(e) There is no indication provided when any aircraft is operating inside (or outside) the TIS-B
Service Volume, therefore it is difficult to know if one is receiving uplinked TIS-B traffic informa-
tion. Assume that not all aircraft are displayed as TIS-B targets.
3. Pilots and operators are reminded that the airborne equipment that displays TIS-B targets is for
pilot situational awareness only and is not approved as a collision avoidance tool. Unless there
is an immediate emergency requiring immediate action, any deviation from an air traffic control