UTC Differential: The difference in time between
that at the present position and UTC.
UTM (Universal Transverse Mercator map
projection system): Also known as Military Grid
Coordinates, the UTM grid consists of 60
north-south/east-west zones, each six degrees wide in
longitude.
V VFR: Visual Flight Rules.
VOR: Very High Frequency Omni-directional range.
A navigational aid that transmits signals such that a
receiver can indicate its current radial or bearing from
the transmitter.
VHF: Very High Frequency. The range of
frequencies between 30 and 300 MHz.
VNAV: Vertical Navigation. See Altitude Assist.
W Waypoint: A navigation fix used in area navigation
and defined by latitude and longitude coordinates.
15-11
Glossary