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6/17/21 

AIM 

with a series of short, regularly spaced eye 
movements that bring successive areas of the sky into 
the central visual field. Each movement should not 
exceed ten degrees, and each area should be observed 
for at least one second to enable collision detection. 
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. 

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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 maneu-
vers 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 train-

ing 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. 

2.  High

wing airplane. 

Momentarily raise the 

wing in the direction of the intended turn and look. 

3.  Low

wing airplane. 

Momentarily lower 

the wing in the direction of the intended turn and look. 

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. 

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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. 

d. 

The serving IFR air traffic facility is not 

responsible to provide approved standard IFR 
separation to an IFR aircraft, from other aircraft, 

ATC Clearances and Aircraft Separation 

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