Fsbuild-2 Flight Planner

Hi,

I think there is a problem with the way pseudo-waypoints are being given in the navigraph data. I don't quite know how I can explain but I will use the OSTOS 3A approach to runway 30 in Oulu, Finalnd, as an example. To do this approach, I should fly to waypoint OSTOS and then continue inbound towards VOR OUK on radial 173 until D14.0. Then I make a DME arc clockwise until I cross radial 279 where I turn to follow radial 289 inbound until D8.0 which is the IAF (MARUG). Here is the chart: https://ais.fi/ais/eaip/aipcharts/efou/ ... 12_STA.pdf

The problem is with the initial part from OSTOS onto the DME ARC. In the navigraph data, the initial waypoint for OSTO3A tries to have the initial waypoint (OSTOS) and the turning point onto the ARC at D14.0 in the same line - see bold line below. The result is that when the approach is selected, the FMS 'thinks' that OSTOS is now at 64.931553 25.359283, which is actually the coordinates of the OUK VOR station rather than the real position which is nearly 30 miles to the south of the field. The transition information, to turn onto the ARC at D14.0 is not shown in any way and the next waypoint shown is D190L (which shows correctly) -> If left to fly in LNAV mode, the aircraft would fly all the way to OUK, then turn back out to get onto the D12 ARC. Also, if I was to just try to fly direct onto the STAR, ie just select it in the FMS, I would not have the waypoint OSTOS added, only the first (broken) transition point comes up. This problem not only messes up the approach, but it also means that any descent calculations are wrong as well since the distances are not right any more!

OSTO3A OSTOS /T353/UD14.0 1700 12 64.931553 25.359283
OSTO3A D190L --- 12 64.734550 25.277905 FO
OSTO3A D207L --- 12 64.753182 25.146380 FO
OSTO3A D224L --- 12 64.787313 25.033104 FO
OSTO3A D241L --- 12 64.834013 24.947889 FO
OSTO3A D258L --- 12 64.889254 24.898245 FO
OSTO3A D279L --- 12 64.992289 24.910831 FO
OSTO3A MARUG 1700 12 64.993889 25.082222

I modified it a bit to try and separate the two things, and this version below actually works, I have added the real coordinates of OSTOS for the first waypoint, then the transition is given the coordinates of OUK VOR, from which it should be 14 miles on radial 173... I guess the /T353/UD14.0 means course 353 until dist 14.0 from the given coordinates, in which case it would explain why it works...

OSTO3A OSTOS 1700 12 64.435000 25.315000
OSTO3A /T353/UD14.0 --- 12 64.931667 25.359167
OSTO3A D190L --- 12 64.734550 25.277905 FO
OSTO3A D207L --- 12 64.753182 25.146380 FO
OSTO3A D224L --- 12 64.787313 25.033104 FO
OSTO3A D241L --- 12 64.834013 24.947889 FO
OSTO3A D258L --- 12 64.889254 24.898245 FO
OSTO3A D279L --- 12 64.992289 24.910831 FO
OSTO3A MARUG 1700 12 64.993889 25.082222

I don't know if it is a problem in the ISG1 coding or the format being provided from Navigraph, but unfortunately it looks like this problem is present in a large number of DME ARC approaches (certainly all the Finnish ones that I have looked at), so I hope you can fix this either with them or in an upcoming patch... (it would be a pain in the *** to have to do them manually for each AIRAC cycle!)

Cheers,
Geoff

Good stuff. Thanks, as ever, for the support!

Geoff

This has been addressed by Navigraph in rev 3.

Regards.
Ernie.

Great! I am really enjoying this feature of the 1.7 update, there are a lot of DME ARC approaches at Finnish regional airports where I fly many of my FS flights...

Geoff