Fsbuild-2 Flight Planner

Hello,

my current setup includes FSX, ActiveSky 2012 (AS2012), and FSBuild 2.4.024 b274.

"Technically", they all play together nicely, this is not the traditional "pointing to correct folder" question...
While FSB builds a plan it duly reports "Retr AS6 winds...etc" (I am assuming the "AS6" is just a "historical" left-over, and OK even when using AS2012?).

It also seems that the winds aloft from AS2012 are in principle included in the FSB plans indeed: the values as seen in the FSB navlog are "roughly" correct.

However, what bothers me is that there are still quite noticeable discrepancies between the wind speeds of AS2012 and those shown in FSB.

To check this more precisely, I created a route in FSB (EDDL-GCTS), exported it (*.pln format), then imported it in AS2012, and compared, waypoint for waypoint, the wind values in the FSB navlog with those shown in AS2012. I used FL340 as cruise altitude because this altitude is directly visible in AS2012, no interpolation needed; and I included only those waypoints at cruise level. (Discrepancies for the climb and descent phase are to be expected, as FSB and AS2012 may use different performance and climb/descent rate values for interpolation).

The outcome is that the numbers agree "roughly", as said, but the remaining discrepancies are too big to be overlooked, certainly not just rounding errors or such.
E.g. at 11 waypoints (out of 30 waypoints compared), the wind direction in FSB differed by more than 10° from that in AS2012; and for 8 waypoints, the wind speed difference was greater than 10 kn, which to me seems not negligible. See the graphics below for details; they show the differences (FSBvalue - AS2012value).

So, why is FSB not actually using (or showing in the navlog) the precise same values (give or take) as in AS2012?
Or is this an expectation based on wrong assumptions?

Moreover, is there any other way than described above to find out which weather (wind) values FSB is actually using?

BTW, earlier I have made similar comparisons frequently for FS2004/AS6.5/FSB, and in that setup always found only minor discrepancies between AS and FSB, easily explained by rounding errors and such.

Note that I am well aware these are all wind predictions anyway, which may or may not be correct (as in Real Life!).
I am not complaining about lack of precision. My goal is rather to make sure that I am using the FSB/AS2012 combo correctly and most efficiently.

Thanks for any comments or tips!

Cheers,
Martin

PS. As an afterthought: Could the issue be that waypoints are not necessarily also actual weather stations?
And both FSB and AS2012 have to interpolate from the latter, and do this in different ways?




FSBvsAS2012_dir.jpg [ 25.83 KiB | Viewed 9557 times ]


FSBvsAS2012_speed.jpg [ 29.12 KiB | Viewed 9557 times ]

The first thing to try is to create your flight plan in FSB with AS running. Take that plan and load it into AS and then run a 'Build' in FSB - that should give you the closest match you are going to get. Remember that wind directions are reported as 'True' in AS; it isn't clear whether wind directions in FSB are shown as true or magnetic. Every wind not associated with an airport in either application is an interpolated approximation. No wind in FSX will actually match exactly with the wind shown in AS (I was one of the AS beta testers and I guarantee that is true) - at a minimum you must convert the FSX data to true or the AS data to magnetic for your location, and even then FSX is not good at replicating input winds. The wind in FSX will change as data updates - it is possible that it will change a lot and bear no resemblance to your planned winds. If you search the forum you can find more material on winds...

DJ

Its probably better to compare what is actually in the 'current_wx_snapshot.txt' file with what is in Fsbuild, rather than comparing Fsbuild to AS2012.

From this end all the matters is if that file is being read correctly.

Select the 'Replace ETA Column with WxSta in Navlog option in the 'Build Options' menu.

This will let you see exactly what Wx station data is being read for each waypoint, then you can compare with Fsbuild is displaying with what is in the actual snapshot file.

If there still is a discrepancy, then post the snapshot file , then I can check it out.

Regards.
Ernie.

Thanks for the comments and suggestions!

I have now repeated the comparison, but this time, as suggested,
¤ using the data not for the route waypoints but for the respective wx stations (airports) as given in the FSB navlog; and
¤ taking the AS2012 data not from the AS GUI but directly from the active current_wx_snapshot.txt file.

However, there are still discrepancies; on the whole they are somewhat smaller than in the comparisons above, but still noticeable. I have also recorded the magvar values for the wx stations; but they are all between 2° and 4° only, thus not sufficient alone to explain the differences.

If you think all this is worth following up (I'm not quite sure myself ), and want to have more details: I have prepared (but not yet appended here * ) a ZIP file which includes the current_wx_snapshot.txt file I used as well as the FSB navlog, and all the comparison data both as OpenOffice/LibreOffice spreadsheet (*.ods) and as a CSV file (for import to e.g. Excel).

Cheers,
Martin

* The file size is 581 kB, and I'm not sure if it can/should be appended directly here to the forum post, or if I should make it available via some other route.