View Full Version : surface wind
van der vart
14th Oct 2003, 01:03
when an aircraft lined up on the runway, what instrument tells the pilot of the surface wind?
inbalance
14th Oct 2003, 01:11
The Radio will tell you
RadarContact
14th Oct 2003, 02:23
This one will: :)
http://www.eapnews.ch/bilder/divers1/windsock_b737_081002.jpg
andyb79
14th Oct 2003, 03:08
ah the wonders of modern technology
Naaah, don't listen to them Van, technology will get you into trouble, just look at the cows, they always stand with their backs to the wind.
av8boy
15th Oct 2003, 11:35
That's not the cow's back really...
Dave
van der vart
16th Oct 2003, 01:41
okay
wind sock helps when on the ground, but what about if a controller ask for spot wind when aircraft is on base leg?
any instruments?
Jerricho
16th Oct 2003, 02:41
Lick you finger and stick it out the window??
(Sorry....... :ouch: )
fatboy slim
16th Oct 2003, 16:23
Ignore the contollers Van!!
The modern Flight Mngt Computers on board calculate the wind very accurately, by working out actual groundspeed and track and comparing it to indicated speed and heading. The GPS inputs allow all of these to be calculated v accurately and updated many times a second. I had to do this with maps, plotters and rulers and one calculation took about five minutes. But I am a bit slow.
Mark 1
16th Oct 2003, 20:05
Seriously though...
The controllers have a wind display, usually based on readings from about 3 different anemometers on 10m high poles.
This allows for individual variation due to buildings and local effects etc.
They also have a measure of recent peak gusts and mean wind strengths.
If you hear a controller pass a surface wind reading, it will be based on that control-tower reading of the anemometers.
av8boy
16th Oct 2003, 23:06
We have a very similar system in the US, except our poles are around 32 feet 10 inches tall. :O
Dave
b777pilot
20th Oct 2003, 21:28
i remem somebody telling this story about a field in the south pacific where the local boys used to throw coconuts into the windsock and got some flight into trouble.
but i watch everything, windsock, smoke, trees blowing, whatever's avail to get her to fly. the INS and the FMCs' are not very helplful when at a standstill, at least not the ones i know of. 80 kts before they come to work?