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Jeezy776

Flight Simulator X - PMDG and tailwind

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Hi I just have a quick question wether or not tailwind and headwind is simulated in fsx? I'm flying the NGX737 and occasionally I get really strong tailwinds or a really strong headwind but it doesn't seem to affect my plane at all. The same with speed really. 

 

So if I'm doing a flight that is say 2 hours long and I get like 50+ tailwind it would still take at least 2hrs if not more.

 

And for the speed
Like when the FMC estimates to arrive at the destination at a certain time and if I increase the cost index and fly at a higher speed it doesn't change at all, still predicts the same.

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It absolutely is simulated.  A couple key things to remember though.  First is differentiating between TAS and GS.  Your PFD displays true airspeed (TAS).  This is the speed of the aircraft relative to the air it is flying through.  This will not change with head or tail winds.  Ground speed (GS) will change (+ for tailwind, - for headwind) and is displayed on the ND depending on your settings. 

 

Regarding your ETA, you have to think about the magnitude of the effect.  If you GS in 0 wind is about 470ish kts, a 20 kt tailwind will shorten your 2 hour trip by only about 5 minutes.  The effects can be huge when you get a 120 kt tailwind across the Atlantic, but are often much smaller.  Cost Index (CI) is an even smaller effect, often changing by only a few kts.  The biggest effect CI changes can have is by changing your climb/descent profiles so that you descend at say 280 kts instead of 250 kts. 

 

Also understand your ETA's on the FMC doesn't have circuit time built in for a vectored approach.  So unless you're on an RNAV approach transitioning off a STAR to FAF all entered perfectly in the FMC, there's usually 5-10 minutes of vectored flying for your circuit that the FMC isn't counting.  So you're ETA of 2:00, should really be 2:07 or so...so when you land in 2:02 you actually are ahead of schedule even though the FMC said 2 hours.  There are a few ways of making the FMC a bit more accurate regarding ETA and vectored approaches, but for the moment I'll leave things here.

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Okay thank you very much for clearing that up. I have another question in that regard however. Because when I plan a flight with PFPX you get the flightplan with all kinds of information. Now what I'm wondering about are the times that PFPX estimates you'll be on each waypoint taking in consideration you CI and load and everything. I always tend to get super delayed even when I have strong tailwind!

 

I start the clock upon takeoff and compare the estimated times on the flight plan to the actual times and sometimes I'm as much as 30 minutes late

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Okay thank you very much for clearing that up. I have another question in that regard however. Because when I plan a flight with PFPX you get the flightplan with all kinds of information. Now what I'm wondering about are the times that PFPX estimates you'll be on each waypoint taking in consideration you CI and load and everything. I always tend to get super delayed even when I have strong tailwind!

 

I start the clock upon takeoff and compare the estimated times on the flight plan to the actual times and sometimes I'm as much as 30 minutes late

 

I don't have or know anything about PFPX, but maybe it could be that the aircraft specifications are not correctly set up within PFPX? That is, maybe PFPX is calculating those ETs for an aircraft that cruises at .85 while you're doing .78 or something like that.

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I don't have or know anything about PFPX, but maybe it could be that the aircraft specifications are not correctly set up within PFPX? That is, maybe PFPX is calculating those ETs for an aircraft that cruises at .85 while you're doing .78 or something like that.

 

Well basically how it works is you choose the CI you want to be cruising with when you're generating a plan (which in my VA is 100) and all I have to do then is set the CI to the same in the FMC

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