Jump to content

Archived

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

Hanse

PFPX and ASN - Differences

Recommended Posts

Hi,

I am using PFPX with ASN and believe that my seetings are OK. After preparing the flight in PFPX I export the flight plan to ASN (FSX format). Then I load the flight plan into ASN and compare those ASN data on this flight plan with the weather data PFPX states on my OFP.  And there are differences. Comparing the data on the flight I found out that the ASN data are correct e. g. they do not meet my OFP data. On a long haul transatlantic flight from EGLL (London Heathrow) to CYQX (Gander/Canada) those discrepancies resulted in a much higher fuel burn of app. 1.500 kg e. g. my EFOB was much higher than actual.

 

Please find some examples below /(whereas the PFPX values are allways lower than the ASN values):

WPT      PFPX                     ASN

ASNIP   177/049               170/059              

DOGAL 197/021               181/034

5420N   263/013               212/021

5330N   327/060               323/063

5240N   286/058               303/096

5050N   260/088               262/081

 

Is there a way to avoid such discrepancies or does anybody know what do to?

Regards,

 

Share this post


Link to post

Using a PFPX server subscription for weather provides an upper wind forecast over time ( you can see this with the map function ) something flightsim weather engines do not have to do, they only need inject weather as of now.

 

It is my understanding, and of course I may be corrected, that PFPX plans with the forecasted winds.

 

On Oceanic flights I have found the ASN figures to be fairly close at the time of waypoint crossing, of course allowing for fluidity of weather :)

Share this post


Link to post
1 hour ago, Hanse said:

Is there a way to avoid such discrepancies or does anybody know what do to?

 

Looking at the "descrepancies" between the PFPX forecast and winds injected by ASN that you show in your table, I would consider the wind direction/speed at the waypoints to be close. I don't think there is anything to do. You need to remember that forecasts are what they are - forecasts and not something Moses brought down from the mountain in stone. I think both PFPX and ASN do a remarkable job for what they cost.

 

You could spend millions of dollars on software and a computer to run that software but you are probably not going to get the forecast and the actual to agree anymore than they do right now.

Share this post


Link to post

Thanks for the input but my question was: Why the ASN weather during the flight is exactly like predicted in its flight plan whereas PFPX predicts in its OFP something different even that the same weather engine / file is used? Maybe PFPX "interpretes" the data in the ASN  "current_wx_snapshot" file in a different way than ASN? Is there a way that PFPX uses the same "interpretation" than ASN?

 

Regards,

   

Share this post


Link to post
6 hours ago, Hanse said:

Thanks for the input but my question was: Why the ASN weather during the flight is exactly like predicted in its flight plan

 

I believe the ASN weather that you see in the flight plan generated by ASN is not a forecast. It is a snapshot of the weather at the time the flight plan is generated.

Share this post


Link to post

×
×
  • Create New...