Template:Short description Template:Distinguish Template:Infobox tool A windsock (also known as wind cone or wind sleeve) is a conical textile tube that resembles a giant sock. It can be used as a basic indicator of wind speed and direction, or as decoration. Windsocks are typically used at airports to show the direction and strength of the wind to pilots, and at chemical plants where there is risk of gaseous leakage. They are also sometimes located alongside highways at windy locations.
At many airports, windsocks are externally or internally lit at night.<ref name="FAA1">Template:Citation</ref> Wind direction is opposite the direction in which the windsock is pointing.Template:Efn Wind speed is indicated by the windsock's angle relative to the mounting poleTemplate:Px2Template:MdashTemplate:Hspin low winds it droops; in high winds, it flies horizontally.
DesignEdit
Alternating stripes of high-visibility orange and white were initially used to help estimate wind speed, with each stripe extended adding 3 knots (5.6Template:Nbspkm/h; 3.5Template:Nbspmph) to the estimated speed. Some circular frame mountings cause windsocks to be held open at one end and the first stripe extended, indicating a velocity of 3 knots even when stripes are not present. A fully extended windsock suggests a wind speed of Template:Convert or greater.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
StandardsEdit
Per FAA standards, a properly functioning windsock orients itself to a breeze of at least Template:Convert and fully extends in a wind of Template:Convert.<ref name="FAA1"/>
Per Transport Canada standards, a 15-knot wind fully extends the windsock; a Template:Convert wind raises it to 5° below the horizontal; and a Template:Convert wind raises it to 30° below the horizontal.<ref>Template:Citation</ref>
ICAO standards specify a truncated cone-shaped windsock at least Template:Convert long and Template:Convert in diameter at the large end. It should be readable from an altitude of Template:Convert and ideally be of a single colour. If it is necessary to use two colours, they should ideally be orange and white, arranged in five alternating bands, with the first and last darker in tone. In wind speeds of Template:Convert or more, they must indicate wind direction to within ±5°.<ref>Template:Citation</ref>
Edit
Wind tees and wind tetrahedrons are two other commonly used wind direction indicators in airports. Wind tees are shaped like an airplane so that they match with the heading of an aircraft ready to take off and land. Wind tetrahedrons always have their pointed ends pointing to the wind. Wind tees and tetrahedrons can swing freely and align themselves with the wind direction, but neither provides an indication of wind speed, unlike a windsock. Since a wind tee or tetrahedron can also be manually set to align with the runway in use, a pilot should also look at the wind sock for wind information, if one is available.<ref>Template:Cite PHAK Template:PD-notice</ref>
See alsoEdit
- Anemoscope – meteorological device for measuring wind direction
- Anemometer – meteorological device for measuring wind speed
- Draco (military standard) – military standard carried by the Roman cavalry
- Koinobori – Japanese decorative carp-shaped windsocks
- Traffic pattern indicator, which may include a windsock at its center
NotesEdit
ReferencesEdit
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