Aeronautical Terms beginning with U

Ultrahigh Frequency

The frequency band between 300 and 3,000 MHz. The bank of radio frequencies used for military air/ground voice communications. In some instances this may go as low as 225 MHz and still be referred to as UHF.

Unfeathering Accumulator

Tanks that hold oil under pressure which can be used to unfeather a propeller.

United States air carrier

A citizen of the United States who undertakes directly by lease, or other arrangement, to engage in air transportation.

User Request Evaluation Tool (URET)

The URET helps provide enhanced, automated flight data management. URET is an automated tool provided at each radar position in selected en route facilities. It uses flight and radar data to determine present and future trajectories for all active and proposed aircraft flights. A graphic plan display depicts aircraft, traffic, and notification of predicted conflicts. Graphic routes for current plans and trial plans are displayed upon controller request. URET can generate a predicted conflict of two aircraft, or between aircraft and airspace.