Aeronautical Terms beginning with U

Ultra-high frequency (UHF)

The range of electromagnetic frequencies between 962 MHz and 1213 MHz.

Uncaging

Unlocking the gimbals of a gyroscopic instrument, making it susceptible to damage by abrupt flight maneuvers or rough handling.

Underpower

Using less power than required for the purpose of achieving a faster rate of airspeed change.

United States Terminal Procedures Publication (TPP).

Booklets published in regional format by the NACO that include DPs, STARs, IAPs, and other information pertinent to IFR flight.

Unusual attitude

An unintentional, unanticipated, or extreme aircraft attitude.

User-defined waypoints

Waypoint location and other data which may be input by the user, this is the only GPS database information that may be altered (edited) by the user.