Pilot/Controller Glossary

4/20/23

PCG B

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1

B

B4UFLY

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 A free downloadable application, which allows operators to check airspace and local advisories

before flying.

BACK-TAXI

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 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

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(See TRAFFIC PATTERN.)

BEACON

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(See AERONAUTICAL BEACON.)
(See AIRPORT ROTATING BEACON.)
(See AIRWAY BEACON.)
(See MARKER BEACON.)
(See NONDIRECTIONAL BEACON.)
(See RADAR.)

BEARING

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 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

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 Weather conditions below the minimums prescribed by regulation for the particular

action involved; e.g., landing minimums, takeoff minimums.

BEYOND VISUAL LINE OF SIGHT (BVLOS)

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 The operation of a UAS beyond the visual capability of the

flight crew members (i.e., remote pilot in command [RPIC], the person manipulating the controls, and visual
observer [VO]), if used to see the aircraft with vision unaided by any device other than corrective lenses,
spectacles, and contact lenses.

BLAST FENCE

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 A barrier that is used to divert or dissipate jet or propeller blast.

BLAST PAD

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 A surface adjacent to the ends of a runway provided to reduce the erosive effect of jet blast and

propeller wash.

BLIND SPEED

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 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

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 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

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(See TRANSMITTING IN THE BLIND.)

BLIND VELOCITY [ICAO]

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 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

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(See BLIND SPOT.)

BLOCKED

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Phraseology used to indicate that a radio transmission has been distorted or interrupted due to

multiple simultaneous radio transmissions.

BOTTOM ALTITUDE– In reference to published altitude restrictions on a STAR or STAR runway transition,
the lowest altitude authorized.