How do you calculate wind speed??

[744pilot 0]

Hi,I was wondering how you calculate the wind speed?Look at my pic. and you see all those arrows, how do you calculate the wind speed for a specific arrow??? Then wat is my wind speed for my assigned arrow?Thanks,http://forums.avsim.net/user_files/82817.jpg

[Mats_J 2]

Ramon,I think the triangles are 50 knot marks, the long lines are 10 knots and the short ones are 5 knot representations.This would mean that your 'arrow' reads 75 knots and is roughly headed W to WSW.Hope it helps,

[744pilot 0]

You think???? Well thanks anyway, I had the same thoughts but didn't know for sure.

[Mats_J 2]

Explanation here"Remember search is your friend"Now I know!!I think you're welcome ;-)

[744pilot 0]

Yes, thank you very match.

[Guest venquessa]

Course devation for wind is calculated "something" like this.You trip distance D is in NM as normal.Take you course C in degrees.Take you wind speed WS, gusts as WG and its heading as WH.What you need to do is this, assume you are traveling in a block of air, but... it is moving too. You are moving relative to it and it is moving relative to the ground.Simplify the wind speed with the formula.Effective WS = WS + 1/2 * (WG-WS).EG:EWS = 20 + 1/2 * ( 35 - 20 )EWS = 27.5Then... take the heading of the wind and your course heading, say...C = 270, WH = 330and subtract them as so.WH - C = 330 - 270 = 60.Next calculate the cross wind component usig the Sine of the angle you calculated above, times the effective wind speed eg:Xwnd = Sin(60) * EWS.Xwnd = Sin(60) * 27.5Xwnd = 23.8 knots.Then the tail / head wind component as the 1-sine of the angle times the wind speed. eg:HTWnd = 1- sin(60) * EWSHTWnd = 1- sin(60) * 27.5HTWnd = 3.7 knotsWhy Sine? Well, sin(90) = 1, so a 90 degree on wind will be ALL XWnd. sin(0) = 0, so a wind at 000 will be 0 Xwnd and all head or tail.As the wind angle is lower than 90 and lower than 270 its a head wind.This tell us that the "block of air" is moving at 3.7 knots towards us, relative to our course and 23.8 knots left of our course.If we fly heading 270 for 1 hour, we will be approximately 3.7 nms shy of our destination and 23.8 miles off course to the left.So, add 3.7nm to your course line and rotate it until it ends about 23 miles (in this case North) of the destination.You also need to realise, as the manual discusses that if the HTWnd was 75 knots (head wind) and your flight time on the course was 6 hours, you would have to take more fuel as you will be flying an extra 6 * 75 knots = 450 nm. Or 450 nm less fuel if it's a tail wind.Fly that heading should bring you very close to target. of course repeating the above calulation iteratively until you margin of error is within normal limits, usually about 5nm either side on airways would make it more accurate. That is what the FMC does but it can do all the calculations in milli seconds and keep doing them constantly, always adjusting heading and fuel forecasts.I know some pilots and mathematians might have words about they way I calculated the above, and they might have a mathmatical way to calculate the course deviation, but it works fairly well as I have put it above. Though I have never tried it, I just use dead reconing when I need to fly a HDG and maintain track in a wind.

[Guest flyinggriffin]

You can pick up a cheap E-6B online or in a pilots shop and save yourself the headache of all those formulas. Since most of us have palm pilots or its ilk there are also programs free out there that will give you winds and leg times.

[744pilot 0]

Thank you very match people,Thats exactly wat I'm lookin for.

[Guest venquessa]

Some of the threads on here worry me. Some of the things I have seen on Nat. Geographic worry me. Some of the things I read in FAA and CAA reports about incidents worry me.Will I ever fly again?I idolised pilots as amazing highly trained, like they would be able to calculate a wind deviation on course in their heads in seconds. Yet the more I research flying practices the more this seems unlikely.A flight out of south america where the static ports were sealed with tape ended up in the drink. The pilots made the following mistakes....The IAS and AlT were iradic and unreliable. So they asked ATC for info.... Leaving their transponder in ALT-TA mode. Doh! ATC was reading back their "wrong" altitude received from their transponder.OK, you might be able to forgive that. However, when the "Too Low, Terrain! Too Low Pull UP" sounds, they don't know it's trggered from a downward looking radar alt and it IS CORRECT. They ignore it.Finally. The whole way through watching this I asked one question. "Why not look out the window?" OK, it's night time and there are clouds.... but at 15,000ft you will still be able to get a very rough idea of your ALT from looking out the window. Turn the cockpit lights out, what for your night vision, can you see the clouds below? Are you in the clouds? What height is the cloud deck? Can you see the stars? Can you see the glint on the ocean? Can you not see the presure ALT on the cabin guage? Is it increasing or decreasing? What do you ears tell you?Nope. They flew into the sea, all souls lost.I am led to believe that airline pilots are no better than trained apes. You lose you FMC and all souls on board have a limited chance of survival.Nuclear air burst of "eBomb" (electomagnetic discharge) and everthing with a transistor in it dies, instantly. Could you still fly? Would you still be trained to know how to fly? From what I hear, see and read the answer is no! Start praying and appologising to God now, you are about to meet him.Yours, Alarmed.

[marcom 139]

Hi Paul,well, I agree, pilots aren't gods. But they definetely aren't "trained apes" either (or that ape must be a real genius!) :-)Pilots are humans and therefore make mistakes. Nothing will ever change that fact. BUT that's the reason why there are two pilots on every airliner and that's why they have a very standardized training. I can't think of any single pilot error that could cause a catastrophe (if the other pilot is in the loop and its only a single error). I've seen pilots do mistakes - with passengers in the rear or in the sim doing their checks. The outcome? I'm still alive and they also still have their licenses. The most important thing is to admit you've done an error and accept criticism!!Unfortunately, there have been situations where pilots unfamiliar with their aircraft made errors and CRM (crew ressource management) failed completely. The outcome, well, you mentioned it aswell.But there have also been many situations (and you dob't hear about them!) where crews did a very good job and saved the day.Remember the DC-10 in Sioux City (it wasn't only the captain that did the job, but the F/O and the deadheading checker aswell!)Then the A320 F/O who noticed a crosscontrol situation at low altitude and saved the day by taking control after the cpt (who was pilot flying) announced the aircraft wasn't responding to his sidestick.The crew of a B767 that landed after suffering from a triple IRS failure in mountaneous region (Kathmandu).There have been many more incidents! So, are these pilots geniuses or gifted / talented aviators? No, they are highly trained airline pilots doing their job. At least in my opinion.I hope this post can change your strong opinion on airline pilots. From what I read in your post, you must be terrified of boarding an aircraft?Regards,Mark

[Guest Zapper]

Talk about a wind up! This is not the forum for this sort of crap but I have GOT to say something in reply! :-madMate, do you think those guys wanted to die? Pull your bloody head in until you have some experience outside of your lounge room, cable TV and MSFS desktop time.When you really know what it is like to have the fear of God in you because you think you and all your passengers are going to die and there is nothing you can do about it then come back and maybe you will get a hearing.I am a 25 yr professional Airline Pilot and have flown in some of the most dangerous places in the world. My professional colleagues and I do not live in a world of childish and ignorant fantasy. We live in a world where any slip can mean death and suffering for a lot of people and we carry that responsibility well.While armchair wankers like you and the media flog the hell out of us using some dramtised and reconstructed TV show for their own profit regardless of the torment of the victims and their families WE are still taking off in fog, snow and storms that would close major highways, flying these guided missiles full of people at close to the speed of sound so high in the atmosphere that to go outside would be instant death because of cold and lack of air and you would be ripped apart by the wind or landing hundreds of tons of aeroplane on tiny runways at speeds faster than race cars.My professional colleagues and I have all buried what was left of more mates than you could guess. Real World Aviation is not the soft safe experience that wankers like you think.. there again nor is crossing the road or driving a car! Tens of thousands of peopel die horribly on the roads every year but becuse the media ignores it for political reasons people like you don't even think about it.So you go spend some money and get in a real aeroplane with a real pilot, climb to 5000' and get him to spin it.. then ask him to do nothing for the first 3000' and then as the world spins crazily around you and the earth rushes up at you in the windscreen you have a good hard think about what will happen if someone with a shedload of skill and experience doesn't recover it. Have another good look at the ground rushing up at you and then think about your family.Man this ####### me off!

[Qavion 19]

"ATC was reading back their "wrong" altitude received from their transponder."I think you under-estimate the complexity of an airplane my friend. There may have been separate outputs from the Air Data Computers to the instruments and to the active ATC Transponder. Unless you had a wiring schematic in your pocket, how would you know? Wouldn't it be best to try it and see? As I recall, the pilots were hoping someone on the ground could determine their height independently, but the ground station didn't have the ability to do that. Whose fault is that?"What height is the cloud deck?"Probably a few thousand feet below the mountains they didn't crash into."Can you see the stars?"Not if they are in clouds."Can you see the glint on the ocean?"Not if it is a moonless sky."Can you not see the pressure ALT on the cabin guage?"ROFL.... Where do you think the cabin pressurisation system gets its data from? (Yep, the same place as the pilots' instruments).Why are you putting all the blame on the pilots. What about the idiots on the ground who left the covers on the pitot/static sensors.Everyone is a genius in hindsight.Cheers.Ian.P.S. If you were driving in your car on a dark and lonely, unsignposted road being followed by a police car with a radar detector and your instruments and lights suddenly failed and the sound proofing of your car prevented you from hearing wind noise and engine rpms. How long would it be before the police pulled you over for exceeding the speed limit or before you crashed into something? Consider a 3rd dimension... There was a cliff by the side of the road. Add a brake failure (pilots can't put on the brakes and pull over by the side of the road). What miraculous driving skills would save you?

[crvm 0]

You know after a good solid year at flying this 737 NG sim, it never prepares one for the real thing or just riding along, sure I know what to push and where it's located but sitting in the rear of a 800 the other day taking off really amazed and scared the crap out of me at the same time. Like I said, I know how it works pretty well BUT I am THANKFULL people like Brad Marsh are behind the controls and not some armchair nillie dillie like myself. Any APE can push - pull - program but it takes a special person to be in control of a mega-ton flying machine with hundreds of people sipping their drinks and watching a good movie! Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

[SierraDelta 1,355]

Brad,Thanks for setting Mr. Campbell straight on this one, 20 years of simming can prepare noone for the kind of situation that those guys experienced.Seriously,S

[Guest hlm65]

You are right:triangles= 50 ktsbig lines= 10 ktssmall lines= 5 kts.