Just curious how airlines can figure a schedule for a particular flight as the aloft winds change sometimes drastically. In my flight planning I usually go to a specific airline and use their schedule and this helps a lot, but how do they do it?I use FSNavigator and when flying westbound, I just add an extra 30 min or hour depending on the distance flown and just load extra fuel. Is there a more exact science?

The timetables for long haul flights build in a wind factor dependant on the season and the direction of flight.From London to LA for example they may assume an average head wind of say 40 knots in summer and 80 knots in winter.What happens in reality of course rarely accords with this.I did this sector last January and we landed in LA exactly one hour earlier than timetabled.I happened to be with the Captain when going through immigration and I mentioned this to him. He replied that there had been no headwind at any time during the flight and the 2 jet streams we crossed were both at right angles to the track!On the day itself the flight crew would have known pretty well exactly what was going to happen and planned accordingly.

Hi,Another option is to use FSBuild, which will import our weather data and then you will get a more accurate fuel plan.Thanks,Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/FSEconomy Member:http://www.fseconomy.com/

>Just curious how airlines can figure a schedule for a>particular flight as the aloft winds change sometimes>drastically. In my flight planning I usually go to a specific>airline and use their schedule and this helps a lot, but how>do they do it?They have *very* good upper air wind forecasts, and most of the time they are pretty close.For us, we can get it close too, but maybe the present FSX upper air wind bug will bite us. At any rate in the northern hemisphere I always assume a westbound ground speed of say 420 knots in my A321, and that works well. Eastbound I assume 470 knots or so. But i modify this based on the wind reports.I don't just 'add 30 mins of fuel and time', I 'add xxx fuel and time based on my predicted ground speed'.RhettAMD 3700+ (@2530 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2 GB Corsair XMS 3-3-3-8, WD 250 gig 7200 rpm SATA2, CoolerMaster Praetorian