AIM
4/20/23
Appendix 3
−
5
Abbreviations/Acronyms
Abbreviation/
Acronym
Meaning
VASI . . . . . . .
Visual Approach Slope Indicator
VCOA . . . . .
Visual Climb Over the Airport
VDA . . . . . . .
Vertical Descent Angle
VDP . . . . . . .
Visual Descent Point
VFR . . . . . . .
Visual Flight Rules
VGSI . . . . . .
Visual Glide Slope Indicator
VHF . . . . . . .
Very High Frequency
VIP . . . . . . . .
Video Integrator Processor
VLOS . . . . . .
Visual Line of Sight
VMC . . . . . .
Visual Meteorological Conditions
V
MINI
. . . . . .
Instrument flight minimum speed, utilized
in complying with minimum limit speed
requirements for instrument flight
VNAV . . . . . .
Vertical Navigation
V
NE
. . . . . . .
Never exceed speed
V
NEI
. . . . . . .
Instrument flight never exceed speed,
utilized instead of V
NE
for compliance with
maximum limit speed requirements for
instrument flight
VO . . . . . . . .
Visual Observer
VOR . . . . . . .
Very High Frequency Omni
−
directional
Range
VORTAC . . .
VHF Omni
−
directional Range/Tactical Air
Navigation
VOT . . . . . . .
VOR Test Facility
VR . . . . . . . .
VFR Military Training Route
V
REF
. . . . . . .
The reference landing approach speed,
usually about 1.3 times V
so
plus 50 percent
of the wind gust speed in excess of the
mean wind speed.
Abbreviation/
Acronym
Meaning
V
SO
. . . . . . . .
The stalling speed or the minimum steady
flight speed in the landing configuration at
maximum weight.
VTF . . . . . . .
Vector to Final
VV . . . . . . . .
Vertical Visibility
VVI . . . . . . .
Vertical Velocity Indicator
V
Y
. . . . . . . .
Speed for best rate of climb
V
YI
. . . . . . . .
Instrument climb speed, utilized instead of
V
Y
for compliance with the climb
requirements for instrument flight
WA . . . . . . . .
AIRMET
WAAS . . . . .
Wide Area Augmentation System
WFO . . . . . . .
Weather Forecast Office
WGS
−
84 . . . .
World Geodetic System of 1984
WMO . . . . . .
World Meteorological Organization
WMS . .
Wide
−
Area Master Station
WMSC . . . . .
Weather Message Switching Center
WMSCR . . . .
Weather Message Switching Center
Replacement
WP . . . . . . . .
Waypoint
WRA . . . . . .
Weather Reconnaissance Area
WRS . . . . . . .
Wide
−
Area Ground Reference Station
WS . . . . . . . .
SIGMET
WSO . . . . . .
Weather Service Office
WSP . . . . . . .
Weather Systems Processor
WST . . . . . . .
Convective Significant Meteorological
Information
WW . . . . . . .
Severe Weather Watch Bulletin
10/5/23
AIM