Note: The following advisory circular has not been updated by the FAA to reflect changes in Part 105.
AC 90-66B—Recommended Standard Traffic Patterns and Practices for Aeronautical Operations at Airports without Operating Control Towers
Department of Transportation—Federal Aviation Administration. 2/25/19 • Initiated
1 PURPOSE OF THIS ADVISORY CIRCULAR (AC). This AC calls attention to regulatory requirements, recommended operations, and communications procedures for operating at an airport without a control tower or an airport with a control tower that operates only part time. It recommends traffic patterns, communications phraseology, and operational procedures for use by aircraft, lighter-than-air aircraft, gliders, parachutes, rotorcraft, and ultralight vehicles. This AC stresses safety as the primary objective in these operations. This AC is related to the right-of-way rules under Title 14 of the Code of Federal Regulations (14 CFR) part 1, § 1.1 (traffic pattern), and part 91, §§ 91.113 and 91.126.
8 BACKGROUND AND SCOPE.
In the interest of promoting safety,
the FAA, through its AIM, Chart
Supplements, ACs, and other publications, provides frequency information, good operating practices,
and procedures for pilots to use
when operating at an airport without an operating control tower. The
FAA believes that observance of a
standard traffic pattern and the use
of CTAF procedures as detailed in
this AC will improve the safety and
efficiency of aeronautical operations at airports without operating
Regulatory provisions relating to
traffic patterns are found in 14 CFR
parts 91, 93, and 97. The airport
traffic patterns described in part 93
relate primarily to those airports
where there is a need for unique
traffic pattern procedures not provided for in part 91. Part 97 addresses instrument approach procedures
(IAP). At airports without operating
control towers, part 91 requires only
that pilots of airplanes approaching
to land make all turns to the left,
unless light signals or visual markings indicate that turns should be
made to the right (see approved
light gun signals in § 91.125, visual
markings and right-hand patterns
in the PHAK, Chapter 14, Airport
Operations, and the AIM, Chapter 4,
Section 3, Airport Operations).
The FAA does not regulate traffic
pattern entry, only traffic pattern
flow. For example, an aircraft on an
instrument approach flying on the
final approach course to land would
follow the requirements dictated by
the approach procedure. A visual
flight rules (VFR) aircraft on a long,
straight-in approach for landing
never enters the traffic pattern
unless performing a go-around or
touch and go after landing (see
Traffic pattern entry information is advisory, provided
by using this AC or by referring to the AIM and the
PHAK. Approaching to land in
relation to traffic patterns by
definition would mean aircraft in the traffic pattern
landing or taking off from an
airport. An aircraft not in the
traffic pattern would not be
bound by § 91.126(b) (see
paragraph 11.3 for aircraft
crossing over midfield above
pattern altitude to enter the
pattern). Requirements for
traffic pattern flow under §
91.126 continue to apply to
other airspace classification
types under § 91.127 (Class E
airspace), § 91.129 (Class D
airspace), and § 91.130 (Class
C airspace), particularly when
a towered airport is currently
operating as a non-towered
9 GENERAL OPERATING PRACTICES.
9.1 Left Traffic.
Use of standard traffic
patterns (left turns) for all aircraft
and CTAF procedures by radioequipped aircraft are required at all
airports without operating control
towers unless indicated otherwise
by visual markings, light gun signals,
airport publications, or published
approach procedure. It is recognized that other traffic patterns
(right turns) may already be in common use at some airports or that
special circumstances or conditions
exist that may prevent use of the
standard traffic pattern. Right-hand
patterns are noted at airports on an
aeronautical chart with an “RP” designator and the applicable runway
next to the airport symbol.
9.2 Collision Avoidance.
The pilot in
command’s (PIC) primary responsibility is to see and avoid other aircraft and to help them see and
avoid his or her aircraft. Keep lights
and strobes on. The use of any traffic pattern procedure does not alter
the responsibility of each pilot to
see and avoid other aircraft. Pilots
are encouraged to participate in
“Operation Lights On,” a voluntary
pilot safety program described in
the AIM, paragraph 4-3-23, that is
designed to improve the “see-andavoid” capabilities.
Unmanned Aircraft. Unmanned aircraft (commonly known as drones
or model aircraft), like manned aircraft, are allowed to operate in
Class G airspace without specific air
traffic control (ATC) authorization
and without required radio communications. The remote PIC and the
Unmanned Aircraft System (UAS)
operator must always yield rightof-way to a manned aircraft and not
interfere with manned aircraft
operations. Additional information
regarding unmanned aircraft operations may be found in AC 91-57, AC
107-2, and 14 CFR part 107.
Operators of UAS are
required to obtain ATC authorization prior to operating in Class B, C,
D, and surface Class E airspaces.
9.3 Preflight Actions.
As part of the
preflight familiarization with all
available information concerning a
flight, each pilot should review all
appropriate publications (e.g., Chart
Supplements, the AIM, and
NOTAMs), for pertinent information
on current traffic patterns at the
departure and arrival airports.
9.4 Traffic Flow.
It is recommended
that pilots use visual indicators,
such as the segmented circle, wind
direction indicator, landing direction indicator, and traffic pattern
indicators that provide traffic pattern information. If other traffic is
present in the pattern, arriving or
departing aircraft should use the
same runway as these aircraft.
Transient aircraft may not know
local ground references, so pilots
should use standard pattern
phraseology, including distances
from the airport.
9.5 Straight-In Landings.
encourages pilots to use the standard traffic pattern when arriving
or departing a non-towered airport
or a part-time-towered airport
when the control tower is not operating, particularly when other traffic is observed or when operating
from an unfamiliar airport.
However, there are occasions
where a pilot can choose to execute
a straight-in approach for landing
when not intending to enter the
traffic pattern, such as a visual
approach executed as part of the
termination of an instrument
approach. Pilots should clearly
communicate on the CTAF and
coordinate maneuvering for and
execution of the landing with other
traffic so as not to disrupt the flow
of other aircraft. Therefore, pilots
operating in the traffic pattern
should be alert at all times to aircraft executing straight-in landings,
particularly when flying a base leg
prior to turning final.
9.6 Instrument Flight Rules (IFR)
Pilots conducting instrument approaches in visual meteorological conditions (VMC) should be
particularly alert for other aircraft
in the pattern so as to avoid interrupting the flow of traffic and
should bear in mind they do not
have priority over other VFR traffic.
Pilots are reminded that circling
approaches require left-hand turns
unless the approach procedure
explicitly states otherwise. This has
been upheld by prior FAA legal
interpretations of § 91.126(b).
Non-instrument-rated pilots might
not understand radio calls referring
to approach waypoints, depicted
headings, or missed approach procedures. IFR pilots often indicate
that they are on a particular
approach, but that may not be
enough information for a non-IFRrated pilot to know your location. It
is better to provide specific direction and distance from the airport,
as well as the pilot’s intentions upon
completion of the approach. For
example, instead of saying,
“PROCEDURE TURN INBOUND
V-O-R APPROACH 36,” it should be
“6 MILES SOUTH … INBOUND
V-O-R APPROACH RUNWAY 36,
LOW APPROACH ONLY” or “6
MILES SOUTH … INBOUND V-O-R
APPROACH RUNWAY 36, LANDING
9.7 No-Radio Aircraft.
Pilots should be
aware that procedures at airports
without operating control towers
generally do not require the use of
two-way radios; therefore, pilots
should be especially vigilant for
other aircraft while operating in the
traffic pattern. Pilots of inbound
aircraft that are not capable of radio
communications should determine
the runway in use prior to entering
the traffic pattern by observing the
landing direction indicator, the
wind indicator, landing and departing traffic, previously referring to
relevant airport publications, or by
9.8 Wake Turbulence.
All aircraft generate wake turbulence. Therefore,
pilots should be prepared to
encounter turbulence while operating in a traffic pattern and especially when in the trail of other aircraft.
Wake turbulence can damage aircraft components and equipment.
In flight, avoid the area below and
behind the aircraft generating turbulence, especially at low altitude
where even a momentary wake
encounter can be hazardous. All
operators should be aware of the
potential adverse effects that their
wake, rotor, or propeller turbulence
has on light aircraft and ultralight
9.9 Other Approaches to Land.
should be aware of the other types
of approaches to land that may be
used at an airport when a pilot indicates they are doing so, which may
or may not be initiated from the
traffic pattern. The more common
types of these include a short
approach, low approach, or overhead approach.
A short approach is executed when
the pilot makes an abbreviated
downwind, base, and final legs
turning inside of the standard
90-degree base turn. This can be
requested at a towered airport for
aircraft spacing, but is more commonly used at a non-towered airport or a part-time-towered airport
when the control tower is not operating, when landing with a simulated engine out or completing a power-off 180-degree accuracy
A low approach is executed when
an aircraft intends to overfly the
runway, maintaining runway heading but not landing. This is commonly used by aircraft flying practice instrument approaches.
An overhead approach is normally
performed by aerobatic or
high-performance aircraft and
involves a quick 180-degree turn
and descent at the approach end of
the runway before turning to land
(described in the AIM, paragraph
5-4-27, Overhead Approach
The following information is intended to supplement
the AIM, paragraph 4-1-9, Traffic
Advisory Practices at Airports
Without Operating Control Towers.
10.1 Recommended Traffic Advisory
All traffic within a
10-mile radius of a non-towered
airport or a part-time-towered airport when the control tower is not
operating should continuously
monitor and communicate, as
appropriate, on the designated
CTAF until leaving the area or until
clear of the movement area. After
first monitoring the frequency for
other traffic present passing within
10 miles from the airport, self-announcing of your position and
intentions should occur between 8
and 10 miles from the airport upon
arrival. Departing aircraft should
continuously monitor/communicate on the appropriate frequency
from startup, during taxi, and until
10 miles from the airport, unless 14
CFR or local procedures require
To achieve the greatest degree of
safety, it is essential that:
1. All radio-equipped aircraft transmit/receive on a common frequency identified for the purpose of airport advisories, as identified in
appropriate aeronautical publications.
2. Pilots use the correct airport name,
as identified in appropriate aeronautical publications, when
exchanging traffic information to
reduce the risk of confusion. For
example, using “Midwest National
Traffic” instead of the town name
“Mosby Traffic” or “Clay CountyTraffic” at KGPH when the airport
name is printed “Midwest National”
on aeronautical charts.
3. To help identify one airport from
another, the correct airport name
should be spoken at the beginning
and end of each self-announce
4. Pilots clarify intentions if a communication sent by either their aircraft
or another aircraft was potentially
not received or misunderstood.
5. Pilots limit communications on
CTAF frequencies to safety-essential information regarding arrivals,
departures, traffic flow, takeoffs,
and landings. The CTAF should not
be used for personal conversations.
10.2 Information Provided by UNICOM.
UNICOM stations may, upon
request, provide pilots with weather
information, wind direction, the
recommended runway, or other
necessary information. If the
UNICOM frequency is designated as
the CTAF, it will be identified in
appropriate aeronautical publications. If wind and weather information is not available, it may be
obtainable from nearby airports via
the Automatic Terminal Information
Service (ATIS) or Automated
Weather Observing System (AWOS).
UNICOM operators are not
required to communicate with
pilots, and if they do, there are no
standards for the information conveyed.
10.3 Self-Announce Position and/or
“Self-announce” is a
procedure whereby pilots broadcast
their aircraft call sign, position, altitude, and intended flight activity or
ground operation on the designated
CTAF. This procedure is used
almost exclusively at airports that
do not have an operative control
tower on the airport. If an airport
has a control tower that is either
temporarily closed or operated on a
part-time basis, pilots should use
the published CTAF to self-announce position and/or intentions
when entering within 10 miles of
Self-announce transmissions may
include aircraft type to aid in identification and detection. Paint
schemes and color or style descriptions may be added to the use of
the aircraft call sign and type, but
should not replace type or call sign.
For example, “MIDWEST TRAFFIC,
TWIN COMMANDER FIVE ONE
ROMEO FOXTROT TEN MILES
NORTHEAST” or “MIDWEST
TRAFFIC, FIVE ONE ROMEO
FOXTROT TWIN COMMANDER
TEN MILES NORTHEAST.” In some
cases, where the type of aircraft
may not be familiar to pilots, the
color and description may be added
to the type and call sign. For
instance, “MIDWEST TRAFFIC,
NOVEMBER THREE TWO DELTA
SIERRA, ORANGE AND WHITE
BIPLANE TEN MILES NORTHEAST.”
When referring to a specific runway, pilots should use the runway
number and not use the phrase
“Active Runway,” because there is no
official active runway at a non-towered airport. To help identify one
airport from another when sharing
the same frequency, the airport
name should be spoken at the
beginning and end of each self-announce transmission.
Pilots are reminded that the
use of the phrase, “ANY TRAFFIC IN
THE AREA, PLEASE ADVISE,” is not
a recognized self-announce position and/or intention phrase and
should not be used under any condition. Any traffic that is present at
the time of your self-announcement
that is capable of radio communications should reply without being
prompted to do so.
10.4 Confusing Language.
To avoid misunderstandings, pilots should avoid
using the words “to” and “for”
whenever possible. These words
might be confused with runway
numbers or altitudes. The use of
“inbound for landing” should also be
avoided. For example, instead of
saying, “MIDWEST TRAFFIC, EIGHT
ONE TANGO FOXTROT TEN MILES
TO THE NORTHEAST, INBOUND
FOR LANDING RUNWAY TWO
TWO MIDWEST,” it is more advisable to say, “MIDWEST TRAFFIC,
EIGHT ONE TANGO FOXTROT TEN
MILES NORTHEAST OF THE
AIRPORT, LANDING STRAIGHT IN
RUNWAY TWO TWO, MIDWEST,” so
it does not confuse runway 4, runway 22, or the use of an IAP on
10.5 Unlisted Frequencies.
is no tower, CTAF, or UNICOM station depicted for an airport on an
aeronautical chart, use MULTICOM
frequency 122.9 for self-announce
procedures. Such airports should be
identified in appropriate aeronautical information publications.
10.6 Practice Instrument Approaches in
practice instrument approaches
should be particularly alert for
other aircraft that may be departing
in the opposite direction or on a
base leg or final approach to the
runway associated with the
approach. Conducting any practice
instrument approach, regardless of
its direction relative to other airport
operations, does not take priority
over other VFR aircraft. Pilots
should be ready to communicate on
CTAF, discontinue the approach,
and enter a traffic pattern as needed, based on the traffic saturation
of the airport and/or the current
runway in use, to maintain aircraft
separation and aviation safety. Pilots
are reminded that circling
approaches, practice or actual,
require left-hand turns unless the
approach procedure explicitly
states otherwise. This has been
upheld by prior FAA legal interpretations of § 91.126(b).
Do not correct
other pilots on frequency (unless it
is safety critical), particularly if you
are aware you are correcting a student pilot. If you disagree with what
another pilot is doing, operate your
aircraft safely, communicate as necessary, clarify their intentions and,
if you feel you must discuss operations with another pilot, wait until
you are on the ground to have that
discussion. Keep in mind that while
you are communicating, you may
block transmissions from other aircraft that may be departing or landing in the opposite direction to your
aircraft due to IFR operations, noise
abatement, obstacle avoidance, or
runway length requirements. An
aircraft might be using a runway
different from the one favoring the
prevailing winds. In this case, one
option is to simply point out the
current winds to the other pilots
and indicate which runway you plan
on using because of the current
11 RECOMMENDED STANDARD
information is intended to supplement the AIM, paragraph 4-3-3, Traffic Patterns, and the PHAK,
11.1 Traffic Pattern Design.
owners and operators, in coordination with the FAA, are responsible
for establishing traffic patterns. The
FAA encourages airport owners and
operators to establish traffic patterns as recommended in this AC.
Further, left traffic patterns should
be established, except where obstacles, terrain, and noise-sensitive
areas dictate otherwise (see
Appendix A, Traffic Patterns).
11.2 Determination of Traffic Pattern.
Prior to entering the traffic pattern
at an airport without an operating
control tower, aircraft should avoid
the flow of traffic until established
on the entry leg. For example, the
pilot can check wind and landing
direction indicators while at an altitude above the traffic pattern, or by
monitoring the communications of
other traffic that communicate the
runway in use, especially at airports
with more than one runway. When
the runway in use and proper traffic
pattern direction have been determined, the pilot should then proceed to a point well clear of the
pattern before descending to and
entering at pattern altitude.
11.3 Traffic Pattern Entry.
Arriving aircraft should be at traffic pattern
altitude and allow for sufficient
time to view the entire traffic pattern before entering. Entries into
traffic patterns while descending
may create collision hazards and
should be avoided. Entry to the
downwind leg should be at a 45
degree angle abeam the midpoint of
the runway to be used for landing.
The pilot may use discretion to
choose an alternate type of entry,
especially when intending to cross
over midfield, based upon the traffic and communication at the time
Aircraft should always enter
the pattern at pattern altitude,
especially when flying over midfield
and entering the downwind directly. A midfield crossing alternate
pattern entry should not be used
when the pattern is congested.
Descending into the traffic pattern
can be dangerous, as one aircraft
could descend on top of another
aircraft already in the pattern. All
similar types of aircraft, including
those entering on the 45 degree
angle to downwind, should be at
the same pattern altitude so that it
is easier to visually acquire any traffic in the pattern.
11.4 Traffic Pattern Altitudes.
It is recommended that airplanes observe a
1,000 foot above ground level (AGL)
traffic pattern altitude. Large and
turbine-powered airplanes should
enter the traffic pattern at an altitude of 1,500 feet AGL or 500 feet
above the established pattern altitude. Ultralight vehicles should
operate no higher than 500 feet
below the powered aircraft pattern
altitude. A pilot may vary the size of
the traffic pattern depending on the
aircraft’s performance characteristics.
11.5 Descent and Base Turn.
pattern altitude should be maintained until the aircraft is at least
abeam the approach end of the
landing runway on the downwind
leg. The base leg turn should commence when the aircraft is at a
point approximately 45 degrees relative bearing from the approach
end of the runway.
11.6 Runway Preference.
takeoff should be accomplished on
the operating runway most nearly
aligned into the wind. However, if a
secondary runway is used (e.g., for
length limitations), pilots using the
secondary runway should avoid the
flow of traffic to the runway most
nearly aligned into the wind.
11.7 Takeoff and Go-Around.
on takeoff should continue straight
ahead until beyond the departure
end of the runway. Aircraft executing a go-around maneuver should
continue straight ahead, beyond the
departure end of the runway, with
the pilot maintaining awareness of
other traffic so as not to conflict
with those established in the pattern. In cases where a go-around
was caused by an aircraft on the
runway, maneuvering parallel, or
sidestepping to the runway may be
required to maintain visual contact
with the conflicting aircraft.
Ask an instructor, Fixed-Base
Operator (FBO) employee, or other
pilots at your departure airport
about special procedures such as
noise abatement departure routes
or local protocols if they are not
apparent or directly communicated
by the FAA. Not every airport has
official noise abatement procedures, nor does every airport consistently share this information with
transient pilots. One inconsiderate
act, even if inadvertent, can undo
months of effort by local pilots and
11.8 Turning Crosswind.
remaining in the traffic pattern
should not commence a turn to the
crosswind leg until beyond the
departure end of the runway and
within 300 feet below traffic pattern altitude. Pilots should make the
turn to downwind leg at the traffic
Pilots should be aware that
the crosswind leg may be longer or
shorter due to weather conditions
that are unusually hot or cold.
11.9 Departing the Pattern.
departing the traffic pattern, airplanes should continue straight out
or exit with a 45-degree left turn
(right turn for right traffic pattern)
beyond the departure end of the
runway after reaching pattern altitude. Pilots need to be aware of any
traffic entering the traffic pattern
prior to commencing a turn.
11.10 Airspeed Limitations.
should not be operated in the traffic pattern at an indicated airspeed
of more than 200 knots (230 mph).
Throughout the traffic pattern, right-of-way rules apply
as stated in § 91.113; any aircraft in
distress has the right-of-way over
all other aircraft. In addition, when
converging aircraft are of different
categories, a balloon has the rightof-way over any other category of
aircraft; a glider has the right-ofway over an airship, airplane, or
rotorcraft; and an airship has the
right-of-way over an airplane or
Parachute operations are
subject to 14 CFR part 105.
Parachute operators are required to
coordinate their operations with
the airport manager before they
take place, and utilize proper radio
notification during operations.
12 OTHER TRAFFIC PATTERNS.
Airport operators routinely establish local procedures for the operation of gliders, parachutists, lighterthan-air aircraft, helicopters, and
ultralight vehicles. Appendix B,
Glider Operations, and Appendix C, Parachute Operations, illustrate
these operations as they relate to
recommended standard traffic patterns.
12.5 Parachute Operations.
All activities are normally conducted under a NOTAM noting the location, altitudes, and time or duration
of jump operations. The Chart
Supplement lists airports where
permanent Drop Zones (DZ) are
Jumpers normally exit the aircraft
either above, or well upwind of, the
airport and at altitudes well above
traffic pattern altitude. Parachutes
are normally deployed between
2,000 feet and 5,000 feet AGL and
can be expected to be below 3,000
feet AGL within 2 miles of the airport.
Pilots of jump aircraft are required
by part 105 to establish two-way
radio communications with the ATC
facility that has jurisdiction over the
affected airspace prior to jump
operations for the purpose of
receiving information in the aircraft
about known air traffic in the vicinity. In addition, when jump aircraft
are operating at or in the vicinity of
an airport, pilots are also encouraged to provide advisory information on the CTAF. For example,
“Chambersburg traffic, jumpers
away over Chambersburg.”
When a DZ has been established at
an airport, parachutists are expected to land within the DZ. At airports
that have not established DZs, parachutists should avoid landing on
runways, taxiways, aprons, and their
associated safety areas. Pilots and
parachutists should both be aware
of the limited flight performance of
parachutes and take steps to avoid
any potential conflicts between aircraft and parachute operations.
12.5.5 Appendix C depicts operations conducted by parachutists.
APPENDIX A. TRAFFIC PATTERNS
Single Runway (Diagram from the AIM, Paragraph 4-3-3)
Key to traffic pattern operations
- Enter pattern in level flight, abeam the midpoint of the runway, at pattern altitude.
- Maintain pattern altitude until abeam approach end of the landing runway on downwind leg, begin descent and turn base at approximately 45 degrees from the intended landing point.
- Complete turn to final at least 1/4 mile from the runway.
- Continue straight ahead until beyond departure end of runway.
- If remaining in the traffic pattern, commence turn to crosswind leg beyond the departure end of the runway within 300 feet of pattern altitude.
- If departing the traffic pattern, continue straight out, or exit with a 45-degree turn (to the left when in a left-hand traffic pattern; to the right when in a right-hand traffic pattern) beyond the departure end of the runway, after reaching pattern altitude.