Although many pilots seem to prefer the method of
horizontal back-and-forth scanning every pilot
should develop a scanning pattern that is not only
comfortable but assures optimum effectiveness.
Pilots should remember, however, that they have a
regulatory responsibility (14 CFR Section 91.113(a))
to see and avoid other aircraft when weather
conditions permit.
4-4-15. Use of Visual Clearing Procedures
a. Before Takeoff. Prior to taxiing onto a runway
or landing area in preparation for takeoff, pilots
should scan the approach areas for possible landing
traffic and execute the appropriate clearing maneuvers to provide them a clear view of the approach
areas.
b. Climbs and Descents. During climbs and
descents in flight conditions which permit visual
detection of other traffic, pilots should execute gentle
banks, left and right at a frequency which permits
continuous visual scanning of the airspace about
them.
c. Straight and Level. Sustained periods of
straight and level flight in conditions which permit
visual detection of other traffic should be broken at
intervals with appropriate clearing procedures to
provide effective visual scanning.
d. Traffic Pattern. Entries into traffic patterns
while descending create specific collision hazards
and should be avoided.
e. Traffic at VOR Sites. All operators should
emphasize the need for sustained vigilance in the
vicinity of VORs and airway intersections due to the
convergence of traffic.
f. Training Operations. Operators of pilot training programs are urged to adopt the following
practices:
1. Pilots undergoing flight instruction at all
levels should be requested to verbalize clearing
procedures (call out "clear" left, right, above, or
below) to instill and sustain the habit of vigilance
during maneuvering.

4. Appropriate clearing procedures should
precede the execution of all turns including
chandelles, lazy eights, stalls, slow flight, climbs,
straight and level, spins, and other combination
maneuvers.
4-4-16. Traffic Alert and Collision
Avoidance System (TCAS I & II)
a. TCAS I provides proximity warning only, to
assist the pilot in the visual acquisition of intruder
aircraft. No recommended avoidance maneuvers are
provided nor authorized as a direct result of a TCAS I
warning. It is intended for use by smaller commuter
aircraft holding 10 to 30 passenger seats, and general
aviation aircraft.
b. TCAS II provides traffic advisories (TA) and
resolution advisories (RA). Resolution advisories
provide recommended maneuvers in a vertical
direction (climb or descend only) to avoid conflicting
traffic. Transport category aircraft, and larger
commuter and business aircraft holding 31 passenger
seats or more, are required to be TCAS II equipped.
1. When a TA occurs, attempt to establish visual
contact with the traffic but do not deviate from an
assigned clearance based only on TA information.
2. When an RA occurs, pilots should respond
immediately to the RA displays and maneuver as
indicated unless doing so would jeopardize the safe
operation of the flight, or the flight crew can ensure
separation with the help of definitive visual
acquisition of the aircraft causing the RA.
3. Each pilot who deviates from an ATC
clearance in response to an RA must notify ATC of
that deviation as soon as practicable, and notify ATC
when clear of conflict and returning to their
previously assigned clearance.
c. Deviations from rules, policies, or clearances
should be kept to the minimum necessary to satisfy an
RA. Most RA maneuvering requires minimum
excursion from assigned altitude.

2. High-wing airplane. Momentarily raise the
wing in the direction of the intended turn and look.

d. The serving IFR air traffic facility is not
responsible to provide approved standard IFR
separation to an IFR aircraft, from other aircraft,
terrain, or obstructions after an RA maneuver until
one of the following conditions exists:

3. Low-wing airplane. Momentarily lower
the wing in the direction of the intended turn and look.

1. The aircraft has returned to its assigned
altitude and course.

ATC Clearances and Aircraft Separation

4-4-11