PRECISION APPROACH RADAR_ APPROACH
Introduction - The precision approach radar (PAR) approach uses radar vice aircraft
equipment to maneuver the aircraft to a position for landing during conditions of low ceiling
and/or poor visibility. In the previous section, you were introduced to radar vectors to final
approach course. During this procedure, the approach controller used his radar capability to
direct your aircraft to a segment of a standard instrument approach procedure.
During a radar approach, the controller will direct your aircraft to a position from which you
can safely land. Radar approaches fall into two classes: (1) airport surveillance radar (ASR)
approaches which provide course and range information only and are thus non-precision
approaches (these use an MDA), (2) precision approach radar (PAR) approaches which provide
course, range and glideslope information and can thus be flown to lower minimums (using a
Decision Height) than ASR's.
The balance of this chapter will address PAR's only. The procedures for ASR's are similar.
1. Preflight - Radar instrument approach minimums are published in tabular form in the
front of FLIP terminal instrument approach procedures (approach plates), providing information
regarding decision height, weather minimums, and glideslope angle. From glideslope angle and
ground speed the pilot can determine the rate of descent required to maintain glideslope on final
using the rate of descent table inside the backcover of the approach plates.
Familiarize yourself with this information as part of your preflight planning when a radar
approach (PAR or ASR) is available at your destination or alternate. Additional information
may be found in the ILS/RADAR section of the IFR Supplement entry.
Figure 21 is a sample of the section in the approach plates which contains information on radar
approaches. For the purposes of illustration we will consider the PAR approach to runway 22 at
a. Under the heading of RADAR (1) is a list of frequencies on which your approach
may be conducted. The X's following the frequencies indicate that the radar site has the
capability to work on that frequency but does not monitor it continuously. The PAR approach to
runway 22 has a glideslope, GS(2), of 3.0 degrees. The threshold crossing height, TCH (3), is 52
feet. This means that if you are on gileslope, as you cross the runway threshold you will be 52
feet above the runway surface. If you remain on glideslope until touchdown you will land 1001'
down the runway point to interception, RPI (4).
b. The next column indicates that the published minimums for this approach apply to all
categories, CAT (5), of aircraft. Decision height, DH (6), is 114 feet in this case. Required
runway visual range, RVR (7), for the approach is 1600 Height above touchdown, HAT (8), is
100 feet. Ceiling and visibility, Ceil-Vis (9), for filing purposes and executing the approach is
INSTRUMENT DEPARTURES AND APPROACHES