TCAS II Provides traffic advisories and resolution advisories. Resolution
advisories provide recommended maneuvers in a vertical direction (climb or
descend only) to avoid conflicting traffic.
In this section, we briefly describe RADAR equipment in general use. This information is
not all-inclusive or a substitute for familiarity with the equipment in use at your facility.
For more detailed information on the capabilities and operating controls of these
systems, study the operator s section of the applicable technical manual.
AN/GPN-27 RADAR (ASR-8)
The ASR-8 is a solid-state, airport surveillance RADAR system. It is used to detect
primary RADAR aircraft targets within 60 miles of the antenna site. The system is
reliable and easy to service. Except for the antenna, major assemblies are duplicated to
provide dual-channel operation. If one channel fails, the operator can switch to the
The ASR-8 is interfaced with the TPX-42 system. Also, the ASR-8 uses a staggered
PRF to prevent the occurrence of blind speeds caused by MTI.
The ASR approach course line must coincide as nearly as feasible with the runway
centerline extended. Maximum error left or right of the runway edges must not exceed
500 feet at a point 1 mile from the approach end of the runway.
AN/GPN-30 Digital Airport Surveillance RADAR (DASR-11), ASR-11
The ASR-11 is the next generation terminal area surveillance RADAR providing primary
surveillance RADAR (PSR) coverage to 60 nm and monopulse secondary surveillance
RADAR (MSSR) coverage to 120 nm. It provides the TRACON air traffic controller with
improved aircraft detection in clutter; National Weather Service (NWS) calibrated six-
level weather data; and MSSR (beacon) data combined into a single digital data
message. ASR-11/AN/GPN 30 is a fully integrated, secure PSR/MSSR system that
the STARS. Both the PSR and MSSR are fully solid-state and have improved reliability
with automatic fault detection and isolation that reduces support costs.
The AN/FPN-63 PAR is a solid-state unit and can be mounted on a remotely controlled
turntable (see Figure 5-22). The coverage of the AN/FPN-63 is 8 degrees in elevation
and 20 degrees in azimuth. It allows either a 10 or 20 mile range selection. When MTI is
used, the RANGE SELECT switch will choose either 10 or 15 miles. The 5-mile range
marks on the AZ-EL scope are brighter than the others. There is also a PAR minimums
marker on the elevation scan that marks the decision height (DH) for the runway in use.