See VSI (Vertical Speed
Verb: "to vent" is the action of opening
the vent to cool the air in the envelope. Noun: an
envelope opening that will automatically close.
The line that activates the cooling
VFR (Visual Flight Rules)
governing aircraft flight when the pilot has visual
reference to the ground at all times.
VHF (Very High Frequency)
range used for air/ground voice and navigational
Precipitation that falls from a cloud and
evaporates before reaching the ground.
The total amount of air or gas
(expressed in cubic feet) contained in a balloon
VSI (Vertical Speed Indicator)
that continuously records the rate at which an
aircraft climbs or descends. Usually measured in
FPM. A required instrument in a balloon.