No. 35. Wind Cone Wind Sock
Estimating the Wind SpeedWindcone are made to orient against the wind when the wind speed reaches three knots (3.5 mph). At that wind speed, only the first segment of the windsock will extend. If the windsock extends to the northeast, the wind comes from the southwest or southwest.
The second segment of the sock extends when the wind speed has reached six knots; the third segment, nine knots; and the fourth segment, 12 knots. At a wind speed of 15 knots (17 mph) or more, the windsock will fully extend and point away from the direction from which the wind originates. |
Other SpecificationsThe FAA recommends either a length of eight feet and a throat diameter of 18 inches or a length of 12 feet and a throat diameter of three feet. The fabric must be water-repellant and colorfast.
The framework the windsock is attached to must be able to hold the throat of the fabric windsock fully open when there is no wind. And it must enable the windsock to pivot like a wind vane. The framework may include lighting for the windsock, or the windsock may be illuminated from within.
The windsock assembly must be able to operate correctly in a temperature range from -67 degrees Fahrenheit (-55 degrees Celsius) to 131 degrees Fahrenheit (55 degrees Celsius) and at a wind speed up to 75 knots (86 miles per hour).
Source: https://aviationrenewables.com/how-to-read-a-wind-cone-windsock/
The framework the windsock is attached to must be able to hold the throat of the fabric windsock fully open when there is no wind. And it must enable the windsock to pivot like a wind vane. The framework may include lighting for the windsock, or the windsock may be illuminated from within.
The windsock assembly must be able to operate correctly in a temperature range from -67 degrees Fahrenheit (-55 degrees Celsius) to 131 degrees Fahrenheit (55 degrees Celsius) and at a wind speed up to 75 knots (86 miles per hour).
Source: https://aviationrenewables.com/how-to-read-a-wind-cone-windsock/