Pilot/Controller Glossary

4/20/23

PCG U

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UNMANNED AIRCRAFT (UA)- A device used or intended to be used for flight that has no onboard pilot.  This
device can be any type of airplane, helicopter, airship, or powered-lift aircraft. Unmanned free balloons, moored
balloons, tethered aircraft, gliders, and unmanned rockets are not considered to be a UA.

UNMANNED AIRCRAFT SYSTEM (UAS)- An unmanned aircraft and its associated elements related to safe
operations, which may include control stations (ground, ship, or air based), control links, support equipment,
payloads, flight termination systems, and launch/recovery equipment.  It consists of three elements: unmanned
aircraft, control station, and data link.

UNPUBLISHED ROUTE

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 A route for which no minimum altitude is published or charted for pilot use. It may

include a direct route between NAVAIDs, a radial, a radar vector, or a final approach course beyond the segments
of an instrument approach procedure.

(See PUBLISHED ROUTE.)
(See ROUTE.)

UNRELIABLE (GPS/WAAS)

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 An advisory to pilots indicating the expected level of service of the GPS and/or

WAAS may not be available. Pilots must then determine the adequacy of the signal for desired use.

UNSERVICEABLE (U/S)

(See OUT OF SERVICE/UNSERVICEABLE.)

UPWIND LEG

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(See TRAFFIC PATTERN.)

URBAN AIR MOBILITY (UAM)

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 A subset of Advanced Air Mobility (AAM), referring to an air transportation

system utilizing highly automated aircraft to transport passengers or cargo in urban/suburban areas.

URGENCY

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 A condition of being concerned about safety and of requiring timely but not immediate assistance;

a potential distress condition.

(See ICAO term URGENCY.)

URGENCY [ICAO]

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 A condition concerning the safety of an aircraft or other vehicle, or of person on board

or in sight, but which does not require immediate assistance.

USAFIB

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(See ARMY AVIATION FLIGHT INFORMATION BULLETIN.)

UTM

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(See UAS TRAFFIC MANAGEMENT.)