-- BROADCAST [ICAO]
BACK-TAXI- A term used by air traffic controllers
to taxi an aircraft on the runway opposite to
the traffic flow. The aircraft may be instructed
to back-taxi to the beginning of the runway or
at some point before reaching the runway end for
the purpose of departure or to exit the runway.
BASE LEG- (See TRAFFIC PATTERN.)
BEACON- (See RADAR.)
(See NONDIRECTIONAL BEACON.)
(See MARKER BEACON.)
(See AIRPORT ROTATING BEACON.)
(See AERONAUTICAL BEACON.)
(See AIRWAY BEACON.)
BEARING- The horizontal direction to or from any
point, usually measured clockwise from true north,
magnetic north, or some other reference point
through 360 degrees.
(See NONDIRECTIONAL BEACON.)
BELOW MINIMUMS- Weather conditions below the minimums
prescribed by regulation for the particular action
involved; e.g., landing minimums, takeoff minimums.
BLAST FENCE- A barrier that is used to divert
or dissipate jet or propeller blast.
BLIND SPEED- The rate of departure or closing
of a target relative to the radar antenna at which
cancellation of the primary radar target by moving
target indicator (MTI) circuits in the radar equipment
causes a reduction or complete loss of signal.
(See ICAO term BLIND VELOCITY.)
BLIND SPOT- An area from which radio transmissions
and/or radar echoes cannot be received. The term
is also used to describe portions of the airport
not visible from the control tower.
BLIND TRANSMISSION- (See TRANSMITTING IN THE BLIND.)
BLIND VELOCITY [ICAO]- The radial velocity of
a moving target such that the target is not seen
on primary radars fitted with certain forms of
fixed echo suppression.
BLIND ZONE- (See BLIND SPOT.)
BLOCKED- Phraseology used to indicate that a radio
transmission has been distorted or interrupted
due to multiple simultaneous radio transmissions.
BOUNDARY LIGHTS- (See AIRPORT LIGHTING.)
BRAKING ACTION (GOOD, FAIR, POOR, OR NIL)- A report
of conditions on the airport movement area providing
a pilot with a degree/quality of braking that
he might expect. Braking action is reported in
terms of good, fair, poor, or nil.
(See RUNWAY CONDITION READING.)
BRAKING ACTION ADVISORIES- When tower controllers
have received runway braking action reports which
include the terms "poor" or "nil,"
or whenever weather conditions are conducive to
deteriorating or rapidly changing runway braking
conditions, the tower will include on the ATIS
broadcast the statement, "BRAKING ACTION
ADVISORIES ARE IN EFFECT." During the time
Braking Action Advisories are in effect, ATC will
issue the latest braking action report for the
runway in use to each arriving and departing aircraft.
Pilots should be prepared for deteriorating braking
conditions and should request current runway condition
information if not volunteered by controllers.
Pilots should also be prepared to provide a descriptive
runway condition report to controllers after landing.
BREAKOUT- A technique to direct aircraft out of
the approach stream. In the context of close parallel
operations, a breakout is used to direct threatened
aircraft away from a deviating aircraft.
BROADCAST- Transmission of information for which
an acknowledgement is not expected.
(See ICAO term BROADCAST.)
BROADCAST [ICAO]- A transmission of information
relating to air navigation that is not addressed
to a specific station or stations.