[SOLVED] FMS - waypoints misaligned

[Stefan]

when i do the following:

begin at LOWK RWY10L

enter flightplan from LOWK to LOWG

departure GRZ1K

arrival ABIRI, RWY ILS35.C, transition GRZ

hold at GRZ

i have an altitude limit at (KFT) which is 11nm from LOWK of 8000A

a few miles after crossing KFT, the virtual (KFT) 8000A suddenly moves away to about 49nm from the current location (??)

when i continue flying this 55deg-track, after crossing GRZ, the missaligned (KFT) disappears,

no sequencing of waypoints is done, no HOLD is executed, GRZ remains magenta, LEGS-display seems to be freezed (no distance-update from GRZ).

when i take FMC out of this "hibernate"-state with DIRECT GRZ + EXEC, it continues flight on the current track and GRZ flickers between 1nm and 49nm every second.

problem is absolutely reproduceable in my environment, screenshots are available.

something seems to go wrong with the FMC here - any ideas?

XPLANE is 10.04 b3

Edited April 4, 2012 by Japo32

[Japo32]

did you select the SID from the airport (GRZ1K) with transition? I suppose you hit the EXEC when entered the flight plan... and also you put the FMC as source for the flight plan.

Philipp still is having issues with his internet connection in germany. Hope he can fix them soon and answer all your problems.

Thanks.

[Stefan]

thank you for the immediate reply! - yes, i entered the arrival with the transition GRZ. i have the screenshots if they can help, but they are about 5MBs

[Japo32]

no.. I mean Departure SID with transition. Now you have to choose the transitions of SIDs also. And if it doesn't have SIDs then choose the runway you are going to use for departuring to show the follow map in the MFD.

When you are flying if you loose a waypoint and still a passed one is in magenta.. try to remove those from the flight plan and make active the next one you are supposed to reach.

[Stefan]

LOWK has no transitions. i cananot imagine, what difference it makes, whether there is a transition or not?

the major problem is the restriction-waypoint, which jumps away unexpectedly - it behaves someway like a computed bottom of descend-point,

which changes position with speed and descend-rate. btw. removing this point generates new unexpected effects.

i did fly this route many times with vas- and wilco-fmc - never had any problems.

maybe the crj-fmc needs a different handling-procedure, but i could not find it.

could you make a short try pls, whith my simple flightplan (crz-alt is 9000ft), i've listed above? - the

problem should be reproduceable.

i had a similar problem at the TSL3A + transition TSL depature in LGTS with the (600) alt-condition-wpt.

fmc never initiates the leftturn at the D2xx-wpt, but chases behind a moving (600)-point.

btw: is there a detailed manual for the crj200-fmc available? (is it a rockwell-collins type?)

[Japo32]

There is a manual in internet. Looking at google the collins manual you will find it in pdf (I cannot post it here because don't know about legal stuff).

Well.. this is the first time I hear something about TOD points or whatever. It seems that is something wrong maybe with the navdata...

But you mention that you have vascore.. vas fmc installed? Could you please remove that plugin if you have to try it? This with the vascore or vas fmc can make unexpected results. Please try it without it.

[Stefan]

i used vas- and wilco-fmc with msfs - but i will doublecheck if there is any vas- related plugin in my xplane setup.

[Japo32]

Microsoft flight simulator has not to be anything with x-plane for sure.. and even vas was there... the convertion here in x-plane are different.

Please also try other routes to see if they are correct.

Did you try the tutorial? was fine? if not.. please try it.

[Stefan]

thx for the documentation-"link"! - exactly what i looked for.

i'll try the tutorial-flight next weekend.

Edited February 23, 2012 by stefanpi

[Stefan]

now i tried the tutorial - it worked very well, except an CDT, when i played around with HOLD after the missed-approach-procedure.

i also did some investigations for my problems mentioned above.

the 2 Waypoints, that cause the problems are

the (KFT) dme-intercept point at the GRZ1K-depature from LOWK

<Sid_Waypoint ID="2">

<Name>KFT</Name>

<Type>DmeIntc</Type>

<Latitude>46.597583</Latitude>

<Longitude>14.562320</Longitude>

<Speed>0</Speed>

<Altitude>8000</Altitude>

<AltitudeCons>0</AltitudeCons>

<AltitudeRestriction>above</AltitudeRestriction>

<Hdg_Crs>0</Hdg_Crs>

<Hdg_Crs_value>056</Hdg_Crs_value>

<Flytype>Fly-by</Flytype>

<BankLimit>25</BankLimit>

<DMEtoIntercept>11.0</DMEtoIntercept>

<Sp_Turn>Auto</Sp_Turn>

</Sid_Waypoint>

and the (600) ConstHdgtoAlt waypoint at the TSL3A-departure from LGTS

<Sid_Waypoint ID="1">

<Name>(600)</Name>

<Type>ConstHdgtoAlt</Type>

<Latitude>0.000000</Latitude>

<Longitude>0.000000</Longitude>

<Speed>0</Speed>

<Altitude>600</Altitude>

<AltitudeCons>0</AltitudeCons>

<AltitudeRestriction>above</AltitudeRestriction>

<Hdg_Crs>0</Hdg_Crs>

<Hdg_Crs_value>344</Hdg_Crs_value>

<Flytype>Fly-by</Flytype>

<BankLimit>25</BankLimit>

<Sp_Turn>Auto</Sp_Turn>

</Sid_Waypoint>

it seems, these types of waypoints are not sequenced correctly by the FMS. when crossing the (KFT)-point, it is not sequenced (becomes from-point, grz would become to-point), but moved 49nm away (??). when continuing the route (with or without deleting the misplaced (KFT)) fms gives an unpredictable couse, drops the hold at GRZ and finally generates a scrambled flightplan.

i did not test and document all the combinations of effects here.

in the tutorial flight id did not find waypoints of these two types causing the problems.

I have added two screenshots, showng the (KFT) on the runway and the moved point after crossing it.

[philipp]

Hi Stefan,

I think I know what the problem is - it is in the interplay of DME intercept waypoints and the turn anticipation. When there is a big turn after the virtual waypoint, everything works fine. If there is a shallow turn (or no turn at all) after the virtual waypoint the turn anticipation becomes narrower than the error margin with which the virtual waypoint is calculated. I will not go into the numerical details here, but it is an error I can and will fix soon.

Philipp

[Stefan]

Hi Philipp,

thank you for your analysis of the problem - seems to be more complex than i thought.

is there a similar problem with the ConstHdgtoAlt-points and will your solution solve my problem at the LGTS-departure to?

Stefan

[Stefan]

Hi Philipp,

i have tested the route LOWK-LOWG with the 1.4.4 -> still the same problem!

after passing (KFT) it jumps away 49 miles and keeps this distance all the time, moving away from the current plane-position.

the problem at LGTS/TLS3A-departure has changed a little bit. the (600)-point now works correctly, but FMS overflys the @D329N without any reaction - i would at least expect sequencing of this waypoint, when overflying manually - the left-turn may be difficult to fly by the AP. i also failed to reintercept the fms-course after turning left manually. In the FMA the FMS becomes the active lateral nav-source, but does strange things, starting with a circle around @D329N. and then holding a 294-degree-course, which is the wrong direction...

Edited March 19, 2012 by Stefan

[philipp]

Talking about two different things here:

1) DME-Intc waypoint in GRZ1K SID: This error still exists in the windows version, reason see here

2) regular waypoint with overfly restriction in TLS3A SID: the @-sign before the waypoint denotes a fly-over restriction on the waypoint (waypoints without @ are fly-by waypoints). That means you have to fly EXACTLY over it, not just pass it. This might be tricky in manual flight. Because I just tried TLS3A fully on autopilot and it overflew D329N and sequenced to the next waypoint without problem. I guess it is rather tricky to trigger the fly-over sequencing when trying to chase the waypoint manually, the margin is REALLY small. If you miss it, simply DIR-INTC to the next waypoint.

Philipp

[Stefan]

Thank you, Philipp, for the information!

I am looking forward to the fixed windows version.

EDIT: I succeeded now with TSL3A following your advice. But fms itself was unable to overfly the @D329N with wind of 30 knots from 10:00, so i continued the route with dir intc TSL.

What is the range for hitting an overfly-waypoint?

Stefan

Edited March 20, 2012 by Stefan

[Stefan]

Resolved in 1.4.5!

thanks, Philipp!