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
(See TRAFFIC PATTERN.)
(See AIRWAY BEACON.)
(See MARKER 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
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.
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
(See BLIND SPOT.)
Phraseology used to indicate that a radio transmission has been
distorted or interrupted due to multiple simultaneous radio
(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/she might expect. Braking action is reported in terms
of good, fair, poor, or nil.
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.