A320 FMGS beta 26

[jeehell]

One idea: check the weight used by the model. I noticed that the default weight is MTOW or even over MTOW. I do use myself this plane with ZFW of around 50tons max. And rarely with more than 70% of fuel.

Regards,
JL

[AirFan]

Hey Fritz,

Thanks for the try... but as JL mentioned it wont have any effect. Thanks anyways.

Cheers,
Rob

[AirFan]

JL,

I am even below that usually... For the last trails I've done the following:
I kept the PAX and cargo as it is and only kept 100% on the left/right main tank. Center and outer tanks are empty. So I think it's not fuel related. The AC was pretty light.

Rob

[flapsdown]

Hello JL,
just downloaded your software which i was able to admire at a friend's homecockpit. Really a great job so far!
My first question in this forum: As I have noticed there is no way to add "arrival transitions to final approach" in a flight plan although they exist in the corresponding ICAO.appr.txt files. Is there a way to enter them which I don't know or is it just impossible? And if impossible: Do you intend to develop MCDU further so that we will be able to enter/use transitions?
Thanks!
rw

[jeehell]

Hello,

Thanks for your kind comments. Concerning APPR transitions, they should be available in the MCDU, they are called APPR VIA (LSK2 I think in STAR selection page).

Regards,
JL

[jeehell]

Hello Rob,

I get back to you on your issues. Do you have any other troubles with AP or is it just at thrust reduction?

JL

[AirFan]

Good Evening JL,

Based on my trails I would say that the frequent stalls after thrust reduction is one of the main issues. In Cruise and descent I didnt notice any bugs wrt the AP, except the vertical profile you mentioned before (including the correct marks for TOD, decel..etc. )
Writing this just gave me the clue that this decreasing speed and the high climbrates after thrust red. could be related with a faulty vertical profile since it only happens in managed mode but not if I select the climbrate manually?? What would happen if the first waypoint after takeoff is so high that the AC can't achieve it?? Same question for any decent, if the waypoint would be too low?? I can do some more checks.

The second issue I would mention is the ILS glide slope tracking which still has very sinusodial character. After initial interception of the GS the A/C often crosses the GS several times before it stabilizes with a constant sinkrate. I am not a pro in controller-stuff but maybe some tuning of the controller could improve the the GS tracking behaviour and to reduce the overshoots. If you need more details I could do some test at constant speed. Let me know what you need to know.

BTW: the strange altiudes given for each waypoint were not related with the "." or ";" setting in windows. I already used the "." setting and sometimes the MCDU still gives me some really strange values for the altiude and the speeds.

Cheers,
Rob

ahhh... I got one more If you shift the AC position in slew-mode TOGA-Thrust kicks in every time you leave the slewmode returning to the actual sim. I guess thats not on purpose.

Many Thanks, JL!

[jeehell]

Hello Rob,

The vertical profile has no effect on the climb rate at take-off. The SRS mode only tries to maintain the IAS target using pitch. Problem is, if it keeps the standard g force limits of the A320, the current flight models accellerates way over the IAS target just after lift-off. So it pitches up a LOT, and then at THR RED, it takes time to pitch down from the 20° nose up while N1 reduces to CLB setting, thus the speed fall... I will try to cheat a bit by allowing bigger G load deviation so it can correct sooner the lift off speed...

For the ILS, do you mean it really overshoots a lot or when GS is captured, it oscillates a tiny bit around the center(meaning no reversion to GS*)?

And concerning the slew mode, the problem is FS sends the speed even in slew mode, so if you move really fast (which usually happens in slew mode...) you go over the VMO/MMO, and if you stop moving the A/C then you go below Vstall, hence the AFLOOR and TOGA...I will try to detect the slew mode condition and block the speed input.

Regards,
JL

[flapsdown]

bonsoir jh,
merci beaucoup pour ton indication. Ca fonctionne parfaitement. Bêtement je n'ai que superficiellement lu le manuel!
Encore une fois: tout mon respect et mes félicitations pour ton projet!
Salutations, René

[jeehell]

No problem René, however try to keep it in English on this forum
There is a French building forum called aircockpit if you wish, I have a thread there as well.

Regards,
JL