Aeronautical Information Manual (AIM), page 385

Index   384 -- Page 385 -- 386

that, when a pilot receives breakout instructions, he/
she assumes that a blundering aircraft is about to or
has penetrated the NTZ and is heading toward his/her
approach course. The pilot must initiate a breakout
as soon as safety allows. While conducting PRM ap-
proaches, pilots must maintain an increased sense of
awareness in order to immediately react to an ATC in-
struction (breakout) and maneuver as instructed by

ATC, away from a blundering aircraft.

2. Communications. To help in avoiding com-

munication problems caused by stuck microphones

and two parties talking at the same time, two frequen-

cies for each runway will be in use during ILS PRM
and LDA PRM approach operations, the primary
tower frequency and the PRM monitor frequency.
The tower controller transmits and receive in a nor-
mal fashion on the primary frequency and also
transmits on the PRM monitor frequency. The monit-
or controller's transmissions override on both
frequencies. The pilots flying the approach will listen
to both frequencies but only transmit on the primary
tower frequency. If the PRM monitor controller initi-
ates a breakout and the primary frequency is blocked
by another transmission, the breakout instruction will
still be heard on the PRM monitor frequency.

At some airports, the override capability may be on other

than the tower frequency (KSFO overrides the final radar
controller frequency). Pilots should carefully review the
dual communications requirements on the AAUP prior to
accepting a PRM approach.

3. Breakouts. The probability is extremely
low that an aircraft will "blunder" from its assigned
approach course and enter the NTZ, causing ATC to
"breakout" the aircraft approaching on the adjacent

ILS or LDA course. However, because of the close

proximity of the final approach courses, it is essential

that pilots follow the ATC breakout instructions pre-

cisely and expeditiously. The controller's "breakout"

instructions provide conflict resolution for the
threatened aircraft, with the turn portion of the
"breakout" being the single most important element
in achieving maximum protection. A descending
breakout will only be issued when it is the only con-
troller option. In no case will the controller descend
an aircraft below the MVA, which will provide at least
1,000 feet clearance above obstacles. The pilot is not
expected to exceed 1,000 feet per minute rate of des-
cent in the event a descending breakout is issued.

4. Hand-flown Breakouts. The use of the
autopilot is encouraged while flying an ILS PRM or
LDA PRM approach, but the autopilot must be disen-
gaged in the rare event that a breakout is issued.
Simulation studies of breakouts have shown that a
hand-flown breakout can be initiated consistently
faster than a breakout performed using the autopilot.

5. TCAS. The ATC breakout instruction is the

primary means of conflict resolution. TCAS, if in-
stalled, provides another form of conflict resolution

in the unlikely event other separation standards

would fail. TCAS is not required to conduct a closely

spaced approach.

The TCAS provides only vertical resolution of air-
craft conflicts, while the ATC breakout instruction
provides both vertical and horizontal guidance for
conflict resolutions. Pilots should always immedi-
ately follow the TCAS Resolution Advisory (RA),
whenever it is received. Should a TCAS RA be re-
ceived before, during, or after an ATC breakout
instruction is issued, the pilot should follow the RA,
even if it conflicts with the climb/descent portion of
the breakout maneuver. If following an RA requires
deviating from an ATC clearance, the pilot must ad-
vise ATC as soon as practical. While following an
RA, it is extremely important that the pilot also
comply with the turn portion of the ATC breakout in-

struction unless the pilot determines safety to be

factor. Adhering to these procedures assures the pilot
that acceptable "breakout" separation margins will
always be provided, even in the face of a normal pro-
cedural or system failure.

5-4-17. Simultaneous Converging
Instrument Approaches

a. ATC may conduct instrument approaches

simultaneously to converging runways; i.e., runways

having an included angle from 15 to 100 degrees, at

airports where a program has been specifically

approved to do so.

b. The basic concept requires that dedicated,
separate standard instrument approach procedures be
developed for each converging runway included.
These approaches can be identified by the letter "V"
in the title; for example, "ILS V Rwy 17
(CONVERGING)". Missed Approach Points must
be at least 3 miles apart and missed approach
procedures ensure that missed approach protected
airspace does not overlap.

Arrival Procedures 5-4-49

Page 385 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   384 -- Page 385 -- 386