major maneuver such as a 360 degree turn. If a pilot
makes a 360 degree turn after obtaining a landing
sequence, the result is usually a gap in the landing
interval and, more importantly, it causes a chain
reaction which may result in a conflict with following
traffic and an interruption of the sequence established
by the tower or approach controller. Should a pilot
decide to make maneuvering turns to maintain
spacing behind a preceding aircraft, the pilot should
always advise the controller if at all possible. Except
when requested by the controller or in emergency
situations, a 360 degree turn should never be executed
in the traffic pattern or when receiving radar service
without first advising the controller.
4-3-6. Use of Runways/Declared Distances
a. Runways are identified by numbers which
indicate the nearest 10-degree increment of the
azimuth of the runway centerline. For example,
where the magnetic azimuth is 183 degrees, the
runway designation would be 18; for a magnetic
azimuth of 87 degrees, the runway designation would
be 9. For a magnetic azimuth ending in the number 5,
such as 185, the runway designation could be either
18 or 19. Wind direction issued by the tower is also
magnetic and wind velocity is in knots.
b. Airport proprietors are responsible for taking
the lead in local aviation noise control. Accordingly,
they may propose specific noise abatement plans to
the FAA. If approved, these plans are applied in the
form of Formal or Informal Runway Use Programs
for noise abatement purposes.
REFERENCE-
Pilot/Controller Glossary Term- Runway Use Program

1. At airports where no runway use program is
established, ATC clearances may specify:
(a) The runway most nearly aligned with the
wind when it is 5 knots or more;
(b) The "calm wind" runway when wind is
less than 5 knots; or
(c) Another runway if operationally advantageous.
NOTE-
It is not necessary for a controller to specifically inquire if
the pilot will use a specific runway or to offer a choice of
runways. If a pilot prefers to use a different runway from
that specified, or the one most nearly aligned with the wind,
the pilot is expected to inform ATC accordingly.

4-3-8

2. At airports where a runway use program is
established, ATC will assign runways deemed to have
the least noise impact. If in the interest of safety a
runway different from that specified is preferred, the
pilot is expected to advise ATC accordingly. ATC will
honor such requests and advise pilots when the
requested runway is noise sensitive. When use of a
runway other than the one assigned is requested, pilot
cooperation is encouraged to preclude disruption of
traffic flows or the creation of conflicting patterns.
c. Declared Distances.
1. Declared distances for a runway represent
the maximum distances available and suitable for
meeting takeoff and landing distance performance
requirements. These distances are determined in
accordance with FAA runway design standards by
adding to the physical length of paved runway any
clearway or stopway and subtracting from that sum
any lengths necessary to obtain the standard runway
safety areas, runway object free areas, or runway
protection zones. As a result of these additions and
subtractions, the declared distances for a runway may
be more or less than the physical length of the runway
as depicted on aeronautical charts and related
publications, or available in electronic navigation
databases provided by either the U.S. Government or
commercial companies.
2. All 14 CFR Part 139 airports report declared
distances for each runway. Other airports may also
report declared distances for a runway if necessary
to meet runway design standards or to indicate the
presence of a clearway or stopway. Where reported,
declared distances for each runway end are
published in the Chart Supplement U.S. For runways
without published declared distances, the declared
distances may be assumed to be equal to the physical
length of the runway unless there is a displaced
landing threshold, in which case the Landing
Distance Available (LDA) is shortened by the amount
of the threshold displacement.
NOTE-
A symbol
is shown on U.S. Government charts to
indicate that runway declared distance information is
available (See appropriate Chart Supplement U.S., Chart
Supplement Alaska or Pacific).

(a) The FAA uses the following definitions
for runway declared distances (See FIG 4-3-5):
REFERENCE-
Pilot/Controller Glossary Terms: "Accelerate-Stop Distance
Available," "Landing Distance Available," "Takeoff Distance
Available," "Takeoff Run Available," " Stopway," and "Clearway."

Airport Operations