ZAON PCAS XRX - Example 3: Prioritizing Close Altitudes

Owner’s Manual | PCAS XRX
UNDERSTANDING PCAS 29
Example 3: Prioritizing Close Altitudes
Vertical trend plays a large part
in the prioritizing of aircraft
threats. In this example, an
aircraft is 200 feet above us and
climbing, and another is 700 feet
below and level. Because we are
descending, the aircraft below is
a greater threat, even though
both the range and the vertical
separation are greater than the
one above.
The same would be true if the
aircraft below was climbing and
we were level or descending.
RELATIVE ALTITUDE
RANGE
2600’
2400’
2200’
2000’
1800’
1600’
1400’
2.0 NM 1.0 NM 0 NM 1.0 NM 2.0 NM
DIRECTION
0.5 NM
1.0 NM
1.5 NM
2.0 NM
2.5 NM
XRX
PRIMARY AIRCRAFT
PRIMARY AIRCRAFT
XRX
SECONDARY AIRCRAFT
SECONDARY AIRCRAFT
RELATIVE ALTITUDE
RANGE
RANGE