Section 5. Terminal Radar
10-5-1. SHUTDOWN OF PAR ANTENNAS
When PAR equipment is not required for ATC controller
training, maintenance, or other use, shut down the
antenna. Keep the main power supply and the high voltage
system energized to permit immediate restoration of PAR
equipment for operational use.
10-5-2. RADAR DISPLAY INDICATORS
a. Radar approach and departure control functions will
normally be conducted from a TRACON. Either direct view or
a CTRD may be used. These functions may be performed from
the tower cab if:
b. Not more than two radar operating positions are
required and CTRDs are used on a permanent basis.
c. More than two operating positions are required and
CTRDs are installed on an interim basis pending the
establishment of a TRACON.
d. On a temporary basis if other than CTRDs are
e. Consider the following if scan conversion type
bright display equipment is used:
f. A standard bright display installation consists of
one operational and one standby scan conversion unit. The
range and centering selected for the master bright display
will be the same on all slaved bright display indicators.
g. If the particular radar operating positions
concerned require a capability for individual beacon
decoding, each bright display position will require a
separate scan conversion unit.
h. That a determination must be made if surveillance
approach capability would be lost using only scan
conversion bright display indicators. If the determination
is that it would be lost, at least one direct view
indicator must be retained.
i. VFR Radar Advisory Service functions will normally
be conducted from the TRACON.
j. A CTRD installed in the tower cab for LC use must
be positioned where it can be conveniently viewed from the
local controller's normal sitting or standing position.
k. PAR functions will normally be conducted in a
l. ASDE indicators must be placed in the tower cab so
as to serve the LC and GC positions.
m. The CTRD may be used for any terminal radar
n. The 12-inch or larger display monitor may be used
in lieu of a CTRD when authorized by the region and the
display is certified by airway facilities. Any display
monitor less than 12 inches must not be used for ATC
separation purposes. It is primarily to provide
alphanumeric readout capability to the CD/FD position at
locations where that position has keyboard access to an
USE OF CERTIFIED TOWER RADAR DISPLAYS
a. At towers
combined with full radar approach control facilities where
controllers rotate between the approach control and the
tower, CTRDs may be used by local controllers for any
terminal radar function provided their ability to satisfy
FAA's air traffic responsibilities regarding the aircraft
operating on the runways or within the surface area for
which the tower has responsibility is not impaired. The
conditions and/or limitations for the radar usage must be
specified by a facility directive.
b. At towers
combined with full radar approach control facilities where
controllers do not rotate between the approach control and
the tower, or at towers not combined with full radar
approach control facilities, CTRDs may be used by local
controllers for the following functions:
1. To determine an aircraft's identification, exact
location, or spatial relationship to other aircraft.
This authorization does not alter visual separation
procedures. When employing visual separation, the
provisions of FAAO JO 7110.65, Air Traffic Control, para 7-2-1,
Visual Separation, apply.
2. To provide aircraft with radar traffic advisories.
3. To provide a direction or suggested headings to VFR
aircraft as a method for radar identification or as an
advisory aid to navigation.
4. To provide information and
instructions to aircraft operating within the surface area
for which the tower has responsibility.
5. To ensure separation between successive departures,
between arrivals and departures, and between overflights
and departures within the surface area for which the tower
has responsibility provided:
(a) There is no airspace delegated to the tower;
(b) The local controllers have radar training and
certification commensurate with their radar duties;
(c) A LOA, approved by the respective Terminal
Operations Service Area Office, exists with the IFR
facility having control jurisdiction which authorizes the
specific radar function and prescribes the procedures to
(d) The LOA prescribes the process for a transition to
nonradar procedures or the suspension of separation
authority in the event of a radar outage;
(e) The procedures for giving and receiving radar
handoffs or pointouts do not impair the local controller's
ability to satisfy FAA's air traffic responsibilities
regarding the aircraft operating on the runways or within
the surface area for which the tower has responsibility;
(f) The procedures for ensuring radar separation do
not require the tower to provide radar vectors.
c. At locations where uncertified tower displays are
in use, the services and phraseology set forth in FAAO JO
7110.65, Air Traffic Control, Chapter 5, Radar, must not
be utilized. Uncertified displays must be used only as an
aid to assist controllers in visually locating aircraft or
in determining their spatial relationship to known
d. Operational applications of tower radar displays
other than those outlined in subparas a and b, and/or the
delegation of airspace to a tower require a staff study as
prescribed in para 2-1-15, Authorization for Separation
Services by Towers.
a. Each radar controller is responsible for
determining on a day-to-day basis if the quality of their
radar display and video display accuracy is satisfactory
for ATC purposes. Radar quality and performance is
determined by comparing identified targets against data
obtained during the commissioning flight check or through
minimum performance criteria determined jointly by air
traffic and Technical Operations personnel. Radar
controllers must be familiar with commissioning flight
check and minimum performance data. Air traffic managers
must make this information available to the controllers.
Aircraft selected for these daily checks should be small
aircraft similar in size to those used in the
commissioning flight checks.
FAAO JO 7110.65, Para 5-1-2, Alignment Check.
b. The daily radar performance check, except at MEARTS
and REHOST facilities, must be a part of the routine
checks of equipment. (See para 4-6-5, Preparation
of FAA Form 7230-4). The check must be accomplished once
each watch. It is recognized that on some watches this
check may not be accomplished because of the lack of
traffic. The facility air traffic manager may request a
special flight check to ensure that the requirements of
para 10-5-4, ASR Performance Checks, are met.
The MEARTS and REHOST operational programs accomplish ASR
performance checks automatically.
10-5-5. DEFICIENCIES IN SYSTEM
Note deficiencies in the radar system on FAA Form7230-4.
Reconcile them as follows:
a. After consultation with the Technical Operations
representative, the terminal air traffic manager or
his/her representative must decide if this radar system is
usable. Consider atmospheric or other phenomena that may
temporarily affect radar performance.
b. Certification by Technical Operations personnel
that a malfunction has been corrected must be entered on
FAA Form 7230-4.
Technical Operations representatives may ground check the
equipment to determine if the radar system is operating
satisfactorily or request a special flight check.
10-5-6. RADAR TOLERANCES
systems must conform to the following tolerances for radar
a. Coverage: A usable
target return (one which is not missed on more than two
consecutive scans) will be maintained along the entire
airway/route or arrival/departure control routes for which
radar service is provided. Tracking accuracy along these
routes will be within the fix/map accuracy in subpara b.
Radar services for arrival or departure routes are
considered to exist between the normal handoff point and a
point 1/2 mile from the end of a
runway or for secondary airports, the point where the
aircraft leaves or enters the bottom fringe of the radar
b. Horizontal: No tolerance assigned.
c. Vertical - Acceptance Check: A complete
radar coverage pattern must be flown to determine whether
the radar meets engineering and operational
d. Commissioning: The vertical coverage pattern
will meet the operational requirements of the facility in
both the horizontal (distance from the antenna to the
outer fringe) and the vertical planes.
f. Fix/map accuracy: Radar accuracy must be
such that reporting aircraft are within a circular area
about the fix, the radius of which is 3 percent of the
fix-to-station distance or 500 feet (1,000 feet for air
traffic control radar beacon system (ATCRBS)), whichever
is the greater.
g. Fixed Target Identification: No tolerance
h. MTI: No tolerance assigned.
Approaches: Radar used for surveillance
approaches must present a usable target return (one which
is not missed on more than two consecutive scans) through
the final course as follows:
to Runway (Straight-in): The surveillance approach
course line will coincide with the runway centerline
extended. Maximum error left or right of the runway edges
must not exceed 500 feet at the missed approach point.
to an Airport (Circling): The approach course may be
aligned to the center of the airport or, where
advantageous, to any portion of the usable landing area.
For helicopters only, the final approach may be
established to a missed approach point not farther than
2,600 feet from the center of the landing area, or for a
point-in-space approach, to a point from which flight to
the landing area must be accomplished by visual reference
to a prescribed route along the surface. In each instance,
approach guidance will be provided to the prescribed
missed approach point. Guidance accuracy must be within
3 percent of the distance between the selected delivery
point and the radar antenna.
l. Surveillance approaches must meet the tolerances in
subparas c1 and c2 or will be canceled.
10-5-7. RECOMMENDED ALTITUDES FOR SURVEILLANCE APPROACHES
locations which provide surveillance approaches, facility
managers must request the office responsible for the
preparation of the approach to provide the recommended
altitudes for the final approach. This information will be
placed in the radar facility where it will be readily
available for the controllers to use as required.
10-5-8. ASDE PERFORMANCE CHECKS
hour prior to the anticipated need to use the ASDE, turn
the equipment on and evaluate its performance.