Archived

This topic is now archived and is closed to further replies.

G-YMML1

Winds Format in FMC. FS2004

Recommended Posts

Hi,I ran into problem entering speeds into FMC. I have extensively used FSB and ASV6.5 for years and never had problems with Boeing's FMC where average wind is entered as XXX/XX. MD11 is different story - its FMC asks for either HWind or Twind. Neither FSB nor ASV6.5 provides such format, so I would appreciate your help on converting XXX/XX into head/tail wind numbers. Perhaps there is some sort of mathemactical approach for that. Thank you for your help

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Simple trig. Compare your average track with the average wind direction, I just estimate the headwind/tailwind vector.For example, KSFO-KJFK track is about 080 and if winds are 320/100 then that means they are blowing from 320, which means they are blowing towards 140. Comparing 080 and 140 there is a 60 deg difference. Now imagin a right triangle where the hypotenuse (long side) is 100 and the two angles are 60 and 30 degrees, just estimate the base of the triangle which is the tailwind, or if a calculator is handy solve for 100cos(60) = 86.6Keep it simple, winds vary from forecast, the track is never a straight (rhumb) line and plus or minus 20% won't matter if you use an adequate contingency in the fuel calculation.If you want to get closer, then use AV6 to get winds for each leg and enter those into the MCDU.

Share this post


Link to post
Share on other sites