Friday, 29 March 2024, 8:46 AM
Site: NFC Learning
Course: NFC Learning (NFC)
Glossary: Glossary of Terms
V

Vs

‘VSR’ means reference stall speed.
‘VSRO’ means reference stall speed in the landing configuration.
‘VSRI’ means reference stall speed in a specific configuration.
‘VSW’ means speed at which onset of natural or artificial stall warning occurs.

W

WAFC

World area forecast centre (WAFC). A meteorological centre designated to prepare and issue significant weather forecasts
and upper-air forecasts in digital form on a global basis direct to States by appropriate means as part of the aeronautical
fixed service.

WAFS

World area forecast system (WAFS). A worldwide system by which world area forecast centres provide aeronautical
meteorological en-route forecasts in uniform standardized formats.

Watt

Watt (W). The power which gives rise to the production of energy at the rate of 1 joule per second.

Way-point

“way-point” means a specified geographical location used to define an area navigation
route or the flight path of an aircraft employing area navigation.

Weber

Weber (Wb). The magnetic flux which, linking a circuit of one turn, produces in it an electromotive force of 1 volt as it is
reduced to zero at a uniform rate in 1 second.

Wet Runway

A runway is considered wet when the runway surface is covered with water, or equivalent, less than
specified in "Contaminated Runway" or when there is sufficient moisture on the runway surface to cause it to
appear reflective, but without significant areas of standing water.

Winching area

Winching area. An area provided for the transfer by helicopter of personnel or stores to or from a ship.

Wypt

Waypoint. A specified geographical location used to define an area navigation route or the flight path of an aircraft employing
area navigation. Waypoints are identified as either:

Fly-by waypoint. A waypoint which requires turn anticipation to allow tangential interception of the next segment of a
route or procedure; or


Flyover waypoint. A waypoint at which a turn is initiated in order to join the next segment of a route or procedure.

Z

Z marker beacon

Z marker beacon. A type of radio beacon, the emissions of which radiate in a vertical cone-shaped pattern.