GPS is completely modifying flight plan since SU4 release

[MSFS 2024] Questions & Community Discussions Aircraft
1

So prior to SU4 being released, we were able to load in custom flight plans that included waypoints based on LAT and LON that displayed correctly in the game’s EFB and would also load to avionics and sync with the GPS unit.

After SU4 came out, the waypoints are being completely changed and make absolutely no sense.
It’s adding legs and changing the flight path. Is there a way I can format my flight plans in such a way as to NOT have the GPS mess with it (this flight plan is set to VFR type, also tried IFR)

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Update: After having discovered the causes, here’s the breakdown of what’s happening.
When you load a flight plan into the EFB, it will show correctly in the EFB if properly formatted

Sending that flight plan to ATC and avionics will modify that flight plan and mess up all waypoints in the following scenarios:

  • If you have no 2024 nav instruments installed
  • If you have older 2020 instruments installed like the GTN750

the messed up flight plan will show in those instruments (the EFB will show it correctly)

However, if you have newer 2024 instruments loaded in via the panel or attachments (like the GNS 430 or 530), the flight plans will load in exactly as they’ve been created, ICAO waypoints will still get renamed but will retain their correct LAT and LON positions and none will be removed or added.

So the underlying problem is the dependency on needing to have updated nav instruments installed in order for the send to ATC feature to work without messing up the original flight plan.
Whatever fix those instruments are employing needs to be done inside the EFB tablet!!

2

Do you have an example PLN file that is causing this issue?

Thanks,
Matt

3

If you take the following xml code and save it out in an PLN file, you’ll get the flight plan shown above in the photos. I tried to upload the PLN directly but it wasn’t an allowed format. Apologies for the lack of indentation, the preformatted text for some reason removes it.

<?xml version="1.0" encoding="UTF-8"?> <SimBase.Document> <FlightPlan.FlightPlan> <DepartureID>KBAB</DepartureID> <DestinationID>PAEI</DestinationID> <Title>KBAB - PAEI</Title> <Descr>Flight from KBAB to PAEI created by Little Navmap 3.0.17</Descr> <FPType>VFR</FPType> <CruisingAlt>70000.000</CruisingAlt> <AppVersion> <AppVersionMajor>12</AppVersionMajor> <AppVersionMinor>1</AppVersionMinor> <AppVersionBuild>282174</AppVersionBuild> </AppVersion> <ATCWaypoint id="D00001"> <ATCWaypointType>User</ATCWaypointType> <WorldPosition>N39° 8' 49.58",W122° 44' 34.21",+052333.29</WorldPosition> <ICAO> <ICAOIdent>D00001</ICAOIdent> </ICAO> </ATCWaypoint> <ATCWaypoint id="D00002"> <ATCWaypointType>User</ATCWaypointType> <WorldPosition>N43° 17' 21.13",W125° 26' 18.82",+070000.00</WorldPosition> <ICAO> <ICAOIdent>D00002</ICAOIdent> </ICAO> </ATCWaypoint> <ATCWaypoint id="D00003"> <ATCWaypointType>User</ATCWaypointType> <WorldPosition>N56° 35' 33.96",W140° 28' 31.56",+070000.00</WorldPosition> <ICAO> <ICAOIdent>D00003</ICAOIdent> </ICAO> </ATCWaypoint> <ATCWaypoint id="D00004"> <ATCWaypointType>User</ATCWaypointType> <WorldPosition>N60° 5' 24.66",W142° 54' 57.71",+070000.00</WorldPosition> <ICAO> <ICAOIdent>D00004</ICAOIdent> </ICAO> </ATCWaypoint> </FlightPlan.FlightPlan> </SimBase.Document>

4

Here’s a photo of the xml I attempted to share above so that you can see what it looks like when it’s passed into the EFB tablet. We also compared it to the one the EFB tablet saves and there’s no changes.

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5

those icao ident numbers may be corrupt or bogus at the very least ?
afaik most of those are only 2-5 characters, no idea if thats why its kicking it but …

here is a similar route i exported just now

<?xml version="1.0" encoding="UTF-8"?>
<SimBase.Document Type="AceXML" version="1,0">
    <Descr>AceXML Document</Descr>
    <FlightPlan.FlightPlan>
        <Title>KBAB to PAEI</Title>
        <FPType>VFR</FPType>
        <RouteType>Direct</RouteType>
        <CruisingAlt>5500</CruisingAlt>
        <DepartureID>KBAB</DepartureID>
        <DepartureLLA>N39° 8' 9.96",W121° 26' 11.70",+000106.02</DepartureLLA>
        <DestinationID>PAEI</DestinationID>
        <DestinationLLA>N64° 39' 56.31",W147° 6' 5.19",+000547.01</DestinationLLA>
        <Descr>KBAB, PAEI created by Little Navmap 3.0.18</Descr>
        <DepartureName>Beale Afb</DepartureName>
        <DestinationName>Eielson Afb</DestinationName>
        <AppVersion>
            <AppVersionMajor>11</AppVersionMajor>
            <AppVersionBuild>282174</AppVersionBuild>
        </AppVersion>
        <ATCWaypoint id="KBAB">
            <ATCWaypointType>Airport</ATCWaypointType>
            <WorldPosition>N39° 8' 9.96",W121° 26' 11.70",+000106.02</WorldPosition>
            <ICAO>
                <ICAOIdent>KBAB</ICAOIdent>
            </ICAO>
        </ATCWaypoint>
        <ATCWaypoint id="YDC">
            <ATCWaypointType>VOR</ATCWaypointType>
            <WorldPosition>N49° 22' 53.59",W120° 22' 25.39",+005500.00</WorldPosition>
            <ICAO>
                <ICAORegion>CY</ICAORegion>
                <ICAOIdent>YDC</ICAOIdent>
            </ICAO>
        </ATCWaypoint>
        <ATCWaypoint id="YXY">
            <ATCWaypointType>VOR</ATCWaypointType>
            <WorldPosition>N60° 37' 8.00",W135° 8' 19.99",+005500.00</WorldPosition>
            <ICAO>
                <ICAORegion>CY</ICAORegion>
                <ICAOIdent>YXY</ICAOIdent>
            </ICAO>
        </ATCWaypoint>
        <ATCWaypoint id="PAEI">
            <ATCWaypointType>Airport</ATCWaypointType>
            <WorldPosition>N64° 39' 56.31",W147° 6' 5.19",+000547.01</WorldPosition>
            <ICAO>
                <ICAOIdent>PAEI</ICAOIdent>
            </ICAO>
        </ATCWaypoint>
    </FlightPlan.FlightPlan>
</SimBase.Document>

let me try a custom wp, maybe thats how they show

they show like this (so still short enough?)

        <ATCWaypoint id="WP1">
            <ATCWaypointType>User</ATCWaypointType>
            <WorldPosition>N55° 40' 50.46",W128° 22' 14.73",+005500.00</WorldPosition>
            <ICAO>
                <ICAOIdent>WP1</ICAOIdent>
            </ICAO>
        </ATCWaypoint>
6

I tried with the ICAO numbers removed as I thought maybe they were the culprits but it made no difference. I do agree though they add number to the flight plan.

7

i think your missing my point (to be sure im not certain this is the issue though)
from my example they may ‘need’ an icao number but that is an organization where

" International Standards and Recommended Practices are developed "

its likely they are limited to less than the 6 digits your using - or the tablet could be

tested with a custom WP1 icao and it loads in game

8

This plan loads successfully into the EFB:

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I don’t know how the GTN works, but if it is using the legacy 2020 GET_FLIGHTPLAN calls from JS, then it could be running into the issue reported here: MSFS2024 GET_FLIGHTPLAN waypoints ident / lat / long

That issue can cause waypoints to be dropped and/or corrupted from the legacy APIs and is still under investigation, I believe.

Thanks,
Matt

9

Yup, the EFB always loads and shows the correct flight plan in without issue. But if you use the “SEND to ATC and Avionics feature”, you’ll notice that GPS units show a completely different “modified” route.

We’ve tested this on the GTN750 as well as other GPS units.
It’s the “send to ATC” that appears to change it.

the problem with this is that we rely on GPS for navigation and auto pilot so having it change our flight plan is a huge problem.

10

I understand. This is the issue that I linked, so the best thing to do is to follow the issue or add your own repro of the issue at that link, since that is where the feedback is tracked.

Thanks,
Matt

11

Ah ok I see what you mean! thanks

12

Just a quick update, I discovered a workaround this morning that I wanted to share in case anyone else encounters this.
If you bring in the GNS430 or 530 units (either through use of a panel entry or attachment of the instrument) it will fix this SEND to ATC mess up on your waypoints.
It will still rename the waypoints regardless of what you have in but it will correctly position them on the map as opposed to assigning random ones and or removing them.

13

The WT GNS430W and GNS530W (the V2 units, not the V1 units, which are from MSFS 2020) use the new MSFS 2024 API for flight plan sync to and from the EFB, so are not subject to the issue with waypoint corruption of the flight plan caused when using the legacy GET_FLIGHTPLAN API along with Send To ATC, which 2020 GPS units will use.

The 2020 GPS units have no knowledge of the EFB (as it did not exist in 2020), so they get their plan from the legacy player flight plan (which is also the ATC flight plan in this case) once when the flight starts. They will not synchronize at any other time (or, at least, the WT units won’t; it’s possible other developers poll the ATC/legacy player flight plan more often).

Thanks,
Matt

14

We managed to find the cause, we were using the send to ATC feature in the new EFB tablet but using older nav instruments to display the flight plan (GTN750).
Unfortunately this older GTN unit was modifying he flight plan and destroying all the waypoints.

Simply including an GNS430 in the aircraft resolved the issue in that the flight plan now shows correctly in both the 430 and the 750.

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15

A slight detour, but some Airbus planes will not transfer an EFB flight plan into the avionics, i.e. the MCDU.

They appear to have been developed with a Simbrief interface, before the EFB became available.

My instinct is that more development of and around the EFB is required.

1 Like