TM250 / P/N 250TM-(xxx)-(xxx)
Operation and Installation
35
Document No.: 03.310.010.71e / Revision: 2.10
Zone 1:
If a traffic item closes in to less than 6 NM with an altitude
difference (relative altitude) of less than 1200 ft, the first zone
is injured. In the traffic display the traffic symbol changes to a
filled diamond
. This proximity alert does not yet indicate a
threat.
Zone 2:
If a traffic item closes in to less than 3 NM with an altitude
difference (relative altitude) of less than 600 ft, the second
zone is injured. In the traffic display the traffic symbol
changes into a yellow full circle
. This classifies the target
as a potential threat.
Zone 3:
If a traffic item is less than 1.5 NM away with an altitude
difference (relative altitude) of less than 300 ft, the third and
most critical zone is injured. In the traffic display the traffic
symbol changes into a red full square
. The target is thus
classified as an imminent threat that requires immediate
action.
Besides the spatial boundaries of these zones, the approach rate is also
taken into account.
An alarm equal to the zone 2 violation will be raised if an encounter is
forecasted in less than 70 seconds. This will happen regardless of the
zone in which the intruder is. (obsolete if target is already inside zone 3).
An alarm equal to the zone 3 violation will be raised if an encounter is
forecasted in less than 20 seconds. This happens regardless of the zone
in which the intruder is..
For Mode S traffic the measured field strength will be compared to pre-
defined threshold values, as well as the flight level (when transmitted).
Mode S traffic is using only two zones wherein the zones 1 and 2 are
combined into one.
Regarding FLARM
®
, the range of reception is comparable to the zone 2
boundaries.
