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View Full Version : Question on SID Contraints on Alt (not a bug report JH :P)



EdwardInBeijing
04-11-2017, 12:50 AM
Hi all,

How do I get the Aircraft to climb according to the constraints on the SID? Although I have all modes on dot, it ignores climb constraints and goes straight to the set transition altitude. I've tried setting the first sid height and then engaging the auto-alt dot mode but that doesn't seem to stop it on the next step up and continues to TA.

Pretty sure I'm missing something, just no idea what. Any help appriciated.

spiliot
04-11-2017, 08:03 PM
Just to make sure there is no confusion please use the airbus terms (selected/managed). Auto-alt-dot is not a mode :)

If you don't know what these two terms mean, then I kindly suggest you do some airbus specific reading, watch some videos on youtube etc, or else you'll be missing a lot on how to fly the bird properly. The user guide pdf in the installation folder of JH can help greatly.

Long story short though, if you have set the proper constraints, an altitude higher than the constraint and a managed climb mode, the PFD FMA indications will be green CLB/magenta ALT and the target altitude in the top of the altitude strip will be the constraint altitude in magenta. If you have a selected mode instead, the indication will be open climb - OP CLB in green and the altitude will be cyan so the aircraft won't stop on the constraint. I also assume AP is enabled.

EdwardInBeijing
04-14-2017, 12:43 AM
Just to make sure there is no confusion please use the airbus terms (selected/managed). Auto-alt-dot is not a mode


If you don't know what these two terms mean, then I kindly suggest you do some airbus specific reading, watch some videos on youtube etc, or else you'll be missing a lot on how to fly the bird properly. The user guide pdf in the installation folder of JH can help greatly.


Long story short though, if you have set the proper constraints, an altitude higher than the constraint and a managed climb mode, the PFD FMA indications will be green CLB/magenta ALT and the target altitude in the top of the altitude strip will be the constraint altitude in magenta. If you have a selected mode instead, the indication will be open climb - OP CLB in green and the altitude will be cyan so the aircraft won't stop on the constraint. I also assume AP is enabled.


Indeed, or even more in short, RTFM. :) My excuse is I've spent so much time playing with the actual sim that flying has been a low priority. Now I've finally got everything working(ish) I can start to concentrate on the details. For what I've been doing up to now none of these things has been an issue but now I'm starting to get down to the nitty-gritty.


So, Yes, I meant in managed mode and AP on 100ft above. (Don't know what I was thinking there). The alt is set to the constraint at the top of the SID usually 6000ft (in my world first cleared alt). At Thrust Reduction altitude engage CL, works fine (usually although I have a problem with sometimes it not seeing that and have to flick AT of/on to get recognised but that's in another thread)










So FCOM Normal Procedures says
Check Vertical Mode CLB if NAV engaged check


Monitoring the AP/FD modes and FMA
Case 1: The FCU selected Altitude is set above the next altitude constraint


This is true in my case as I've set for the top of the SID, but it gives no other indication unlike for


Case 2: The FCU selected altitude is set at the next altitude constraint (and then helpfully) The aircraft will automatically levels [sic] off at this altitude.


To resume climb automatically when waypoint AAA is reached apply the following.... (fair enough, but sometimes a bit awkward for changes of 1000ft on turns in short distances)


So my case is case 1, but it doesn't actually tell me anything useful, like 'It will ignore the constraints and go straight to FCU selected altitude'. The constraints show magenta on the PFD.


So my question is - is this assumption about case 1 correct? I'm guessing not, and that it should try to manage to hit each constraint like it does on the way on down. But it doesn't even try to hit constraints, it just goes straight to the FCU altitude.


Cheers




PS. I remember where I got the Alt Dot from, that's what it's called in Skalarki IO Profiler, which I've spent the last three days trying to configure for the latest version -.-

spiliot
04-14-2017, 01:25 PM
Monitoring the AP/FD modes and FMA

You don't seem to confirm the modes in your write-up.

Could you post a few screenshots/photos of the PFD/ND and MCDU flightplan showing the constraints, at any point after setting THR CLB and before reaching the first constraint?