NFC Learning

‘V_F1’ means the design flap speed for procedure flight conditions.
*‘V_FC/M_FC’ means maximum speed for stability characteristics.
‘V_FE’ means maximum flap extended speed.

'V_FTO’ means final take-off speed.
‘V_H’ means maximum speed in level flight with maximum continuous power.
’V_LE’ means maximum landing gear extended speed.

‘V_LO’ means maximum landing gear operating speed.
‘V_LOF’ means lift-off speed.
‘V_MC’ means minimum control speed with the critical engine inoperative.
'V_MCA' means the minimum control speed, take-off climb.
‘V_MCG’ means the minimum control speed, on or near ground.
‘V_MCL’ means the minimum control speed, approach and landing.
‘V_MO/M_MO’ means maximum operating limit speed.
‘V_MU’ means minimum unstick speed.
‘V_NE’ means never-exceed speed.
‘V_R’ means rotation speed.
‘V_RA’ means rough airspeed.

V_S’ means the stall speed or the minimum steady flight speed at which the aeroplane is controllable.
‘Vso’ means the stall speed or the minimum steady flight speed in the landing configuration.
‘Vs1’ means the stall speed or the minimum steady flight speed obtained in a specified configuration.
’Vs1g’ means the one-g stall speed at which the aeroplane can develop a lift force (normal to the flight
path) equal to its weight.
‘V_T’ means maximum aerotow speed (JAR-22 only).
‘V_T’ means threshold speed.
a ‘V_TMAX’ means maximum threshold speed.

‘V_TOSS’ means take-off safety speed for Category A rotorcraft.
‘V_W’ means maximum winch-launch speed (JAR-22 only).

'V_Y' means speed for best rate of climb.
'V₁ means take-off decision speed. The maximum speed in the take-off at which the pilot must take the first action (e.9. apply
brakes, reduce thrust, deploy speed brakes) to stop the aeroplane within the accelerate-stop
distance. V₁ also means the minimum speed in the take-off, following a failure of the critical engine at
V_EF, at which the pilot can continue the take-off and achieve the required height above the take-off
surface within the take-off distance.
'V₂' means take-off safety speed.
'V_2min means minimum take-off safety speed.
'V₃' means steady initial climb speed with all engines operating.

'V_A’ means design manoeuvring speed.

Volcanic ash advisory centre (VAAC). A meteorological centre designated by regional air navigation agreement to provide
advisory information to meteorological watch offices, area control centres, flight information centres, world area forecast
centres and international OPMET databanks regarding the lateral and vertical extent and forecast movement of volcanic
ash in the atmosphere following volcanic eruptions.

'Variable Pitch Propellers’ means a propeller, the pitch setting of which changes or can be changed,
when the propeller is rotating or stationary. This includes:-

a.) A propeller, the pitch setting of which is directly under the control of the flight crew (controllable
pitch propeller).

b) A propeller, the pitch setting of which is controlled by a governor or other automatic means
which may be either integral with the propeller or a separately mounted equipment and which
may or may not be controlled by the flight crew (constant speed propeller).

c) A propeller, the pitch setting of which may be controlled by a combination of the methods of a.
and b.

Visual Approach Slope Indicator, and TVASI (T-VASI)

'V_B’ means design speed for maximum gust intensity.

'V_C’ means design cruising speed.

'V_D/M_D’ means design diving speed.

VHF digital link (VDL). A constituent mobile subnetwork of the aeronautical telecommunication network (ATN), operating
in the aeronautical mobile VHF frequency band. In addition, the VDL may provide non-ATN functions such as, for
instance, digitized voice

V_DF/M_DF’ means demonstrated flight diving speed.

Vectoring. Provision of navigational guidance to aircraft in the form of specific headings, based on the use of an ATS
surveillance system.

‘V_EF' means the speed at which the critical engine is assumed to fail during take-off.

‘V_F' means design flap speed.

“visibility” for aeronautical purposes is the greater of:

a) the greatest distance at which a black object of suitable dimensions, situated near the
ground can be seen and recognised when observed against a bright background;

b) the greatest distance at which lights in the vicinity of 1000 candelas can be seen and
identified against an unlit background;

Note: The two distances above have different values in air of a given extinction coefficient
and the latter b) varies with the background illumination. The former a) is represented by
the meteorological optical range (MOR).

Visitor. Any person who disembarks and enters the territory of a Contracting State other than that in which that person
normally resides; remains there lawfully as prescribed by that Contracting State for legitimate non-immigrant purposes,
such as touring, recreation, sports, health, family reasons, religious pilgrimages, or business; and does not take up any
gainful occupation during his stay in the territory visited.

Visual approach procedure. A series of predetermined manoeuvres by visual reference, from the initial approach fix, or where
applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, if
a landing is not completed, a go-around procedure can be carried out.

VOLMET. Meteorological information for aircraft in flight.
Data link-VOLMET (D-VOLMET). Provision of current aerodrome routine meteorological reports (METAR) and
aerodrome special meteorological reports (SPECI), aerodrome forecasts (TAF), SIGMET, special air-reports not
covered by a SIGMET and, where available, AIRMET via data link.
VOLMET broadcast. Provision, as appropriate, of current METAR, SPECI, TAF and SIGMET by means of continuous
and repetitive voice broadcasts.

Volt (V). The unit of electric potential difference and electromotive force which is the difference of electric potential between
two points of a conductor carrying a constant current of 1 ampere, when the power dissipated between these points is
equal to 1 watt.

‘V_SR’ means reference stall speed.
‘V_SRO’ means reference stall speed in the landing configuration.
‘V_SRI’ means reference stall speed in a specific configuration.
‘V_SW’ means speed at which onset of natural or artificial stall warning occurs.