lazerin Posted January 22, 2009 Posted January 22, 2009 I'm getting conflicting information about what a standard windsock will indicate in terms of wind strength. I've heard that the standard modern aerodrome primary white windsock, aka "Wind Direction Indicator" (according to CASA), is horizontal at wind strengths greater than 30 knots. However, I've also heard 15 knots is the correct number. Can anyone shed some light?
Mikey_A Posted January 24, 2009 Posted January 24, 2009 G'day mate, I was taught 30kts when at full strength, and that was the scale I used when I estimated 25kts last Monday at Aldinga and the instructor didn't disagree. Michael.
lazerin Posted January 24, 2009 Author Posted January 24, 2009 Thanks Mikey, 30 knots seems like the right number. Any idea what the other positions would indicate? Is it a linear sort of scale? e.g. if the sock is at 45 degrees it'll be 12knots?
Guest brentc Posted January 24, 2009 Posted January 24, 2009 It's a little more complicated, as in theory White socks were a lighter strength and yellow socks were higher rated if I have that the right way around. Probem is that not all wind sock manufacturers stuck to the standard. I was of the belief that white was 20 knots and yellow 30 when blowing horizontal.
lazerin Posted January 24, 2009 Author Posted January 24, 2009 Hey Brent, my understanding was that the white windsock is supposed to be the "primary" windsock at an aerodrome with the yellow ones I guess being "secondary"....whatever that means.
hihosland Posted January 24, 2009 Posted January 24, 2009 WINDSOCK: The windsock not only gives a good indication of the direction but can also give a fair idea of the wind speed. Use the Primary windsock - that's the white one. The old style canvas windsocks that were used in the past were just horizontal at 30 knots. A Primary Wind Indicator in 15+ knots of wind The modern lightweight windsock is horizontal with a windspeed of 15 knots or more. 5° below the horizontal would indicate 10 knots and 30° below the horizontal would indicate 6 knots. A windspeed of 3 knots or more will cause the windsock to rotate about its shaft and indicate the wind direction. Source: Transport Canada Civil Aviation AGA - 5.0 Markers, Markings, Signs and Indicators and FAA Advisory Circular 150/5345-27D - FAA Specification for Wind Cone Assemblies. above copied from the Schoefields newsletter
lazerin Posted January 24, 2009 Author Posted January 24, 2009 Uh oh...controversy. Would those standards apply to CASA and Australia?
Ultralights Posted January 24, 2009 Posted January 24, 2009 YSBK has a even mix of White and Yellow socks, a good example today, wind was reported on the ATIS at 25-30kts, the white socks were almost horizontal, and the yellow, about 15 deg from horizontal
Mikey_A Posted January 24, 2009 Posted January 24, 2009 The BAK is handy! I quote "The windsock is a vital indicator to the pilot of wind strength and direction. Your instructor will show you how to read the windsock" end quote!
facthunter Posted January 24, 2009 Posted January 24, 2009 Windsock info. The signal thing is that CASA regard it as a "wind direction indicator." , and no more. There is probably NO standard out there for wind strength. When you fly over the aerodrome you cannot discern the angle that the sock presents to the horizontal anyhow. The only time that you can get an idea of the wind strength is by the crab angle you need on final to maintain the centreline, If The wind has a significant crosswind component. Nev..
Student Pilot Posted January 24, 2009 Posted January 24, 2009 The only time that you can get an idea of the wind strength is by the crab angle you need on final to maintain the centreline, If The wind has a significant crosswind component. Nev.. Or listen to the AWIS
hihosland Posted January 24, 2009 Posted January 24, 2009 From website of windsock manufacturer =================== 8 & 12 Foot Windsocks. Wind Socks of 8 & 12 Foot. These are available in white, or yellow, and are also available in a choice of standard weight or heavy duty versions. the heavy duty version being for places of extreme wind, cyclone prone, or tropical areas. The 8 & 12 foot windsocks are calibrated for Aviation use, fitted with an internal hoop and four large attach eyelets, and is supplied with heavy duty cable ties to attach to a 2ft diameter frame for the 8ft windsock, or a 3ft frame for the 12ft version. The heavy duty windsock will outlast the standard weight by an estimated 50% under the same give conditions. The standard weight windsock is slightly more 'active' in very light wind conditon. 12ft windsocks are the 'standard' for use at licenced and council airstrips and airports. It is quite possible that there are several 'primary' windsocks at an airport, (one for each runway, and often one near the end of each runway. Colour choice of windsocks for non commercial use is simply a matter of what stands out the best against the background colour as seen from the air. Yellow is easier to see against a background of sky, or as seen from the ground. Both colours illuminate well with the 12 volt lighting option, as the materials used have good fibre optic qualities.
turboplanner Posted January 24, 2009 Posted January 24, 2009 Ah, Hihosland, my flying in crosswinds is better than I thought!
bruce01 Posted January 25, 2009 Posted January 25, 2009 Hihosland, I am in the market for a windsock myself, what website is that info from? Cheers, Bruce
hihosland Posted January 25, 2009 Posted January 25, 2009 Weathervanes, Rain Guages, Wind Socks, Windmills, and more at Glenview Products http://www.glenviewproducts.com.au/catalog/civilaviation.php cheers Davidh
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