Bugs when editing VNAV constraints
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Hiya! I'm an avid user of the BAe for MSFS2020. I've encountered a small number of bugs with the UNS-1. I hope this is the right place to report them.
For reference, I almost always fly two legs in one session, and, on a modern profile STAR I will generally edit the vertical constraints to create a more consistent descent path than what the UNS-1 defaults to, which is the lowest allowable altitude at each point. As a simple example -- if AAAAA is at 17,000, BBBBB is 20 miles later at or above 12,000, and CCCCC is 20 miles later at 10,000, the UNS-1 will act as though the desired path is 17,000 --> 12,000 --> 10,000. In reality a more consistent descent would put you at 13,500 at BBBBB, leaving you with 17,000 --> 13,500 --> 10,000. Before starting a descent via a STAR I will look at all of the points along it and make adjustments in this manner. It's a fun mental challenge and a great way to make the somewhat primitive UNS-1 fly these modern profile descents quite beautifully.
I appreciate that I may be the only one in the world doing this, LOL. In any event, I'm sure that this feature was not thorughly tested, so, no shade is intended with the below reports.
Three bugs I've encountered with this process as as follows:
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When starting the second flight, I will use the MENU option to "Delete Flightplan" and start entry anew, and this works fine. However, I almost always have to manually set the "current to point" to the second in the list, as it seems to retain the last known "current to point" from the first flight. This should be re-initialized along with everything else in the box when "Delete Flightplan" is activated.
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When editing vertical constraints on the second page of the VNAV screen, I select the point name that I want to edit, but then when the white box indicates I am now entering the new altitude nothing appears. I can still click each number and hit "ENTER" and it appears, but, while typing it does not show any acknowledgment of each new digit entered. Took me a couple tries to realize it was still registering what I typed but failing to display it.
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Often when editing a VNAV contraint, the one after or before it will simply disappear, and I have to re-insert it. This then cascades into me having to manually re-enter the ENTIRE set of VNAV constraints on a STAR, when I really only wanted to edit one or two (as described above). This most often happens on a second flight within the same session, but, as of last night has now happened to me on the first flight in a session as well.
Anyway, these minor annoyances don't detract from an AMAZING fun plane to fly, particularly now that I'm starting to become "1" with the UNS. Awesome work. Thanks so much!
-Rob AKA SlantAlphaAdventures
twitch.tv/slantalphaadventures -
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SlantAlphaAdventures
“ a fun mental challenge and a great way to make the somewhat primitive UNS-1 fly these modern profile descents quite beautifully.”
They are called ‘constraints’ for a reason; editing them can cause a cascade of other entries.
If you want a mental challenge and wish to fly the ‘big picture’, try doing what airlines pilots do, and use mental arithmetic… Your approach to a solution is all a bit “generation magenta-line”, sorry. I assume you will know to what I am referring?
btw, have you set / there set a ROD in the UNS? If so, that may well throw your pre-pre altitude/levels to pot.
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@Paul-Cairns said in Bugs when editing VNAV constraints:
SlantAlphaAdventures
“ a fun mental challenge and a great way to make the somewhat primitive UNS-1 fly these modern profile descents quite beautifully.”
They are called ‘constraints’ for a reason; editing them can cause a cascade of other entries.
If you want a mental challenge and wish to fly the ‘big picture’, try doing what airlines pilots do, and use mental arithmetic… Your approach to a solution is all a bit “generation magenta-line”, sorry. I assume you will know to what I am referring?
btw, have you set / there set a ROD in the UNS? If so, that may well throw your pre-pre altitude/levels to pot.
There is nothing "wrong" or against intentions about editing constraints to input a specific level which fulfils the above/below criteria the constraint sets (and it should certainly not cause a cascade of other entries). Could be due to fx ATC assigning a specific level to you, wanting a specific level for CDO, anticipating a shortcut on arrival, etc.
And unless the real UNS-1 has a known quirk/bug where it can't handle editing without it then basically deleting constraint levels for following waypoints, it is good that Rob reports it. I have had some similar issues with it as well, but haven't flown 2020 much lately, so don't have specifics to report.And sure, both real and sim pilots are able to the do the basic descend arithmetic - but every good pilot also uses whatever tools he has available to improve situational awareness for monitoring and planning purposes.
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What is wrong with setting the required ROD/descent angle within the UNS menu and allowing the TOD (for the constraint) to be calculated by the UNS?
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@Paul-Cairns becuase the UNS-1 defaults to calculating the rate to reach the LOWEST ALLOWABLE altitude at EVERY point. That is not the ideal economical descent profile. The ideal economical descent profile is usually the one which keeps you highest for longest, but probably more important is that it avoids periods of leveling off and then descending again.
If you have a descent where you have to be at or above 17,000 at point A, and then at or above 10,000 at point B, but then EXACTLY at 10,000 at point C, the UNS-1 will guide you to 10,000 by point B and you'll stay at 10,000 until point C. If you figure out an altitude you'd rather be at when crossing point B, you could override the vertical constraint there and the UNS-1 can provide that nice smooth descent guidance all the way down. Now, in this example, it's simple enough just to DELETE the constraint at point B altogether. But it's a simple example. Modern profile descents often have upwards of 8, 10 constraints along the way. If I sketch out what I think is an ideal profile to meet them, I can then follow the guidance from the box.
You're correct that I can also do it mentally. I could do (and HAVE done) that for the entire flight, start to finish. But then why have the VNAV at all? For that matter -- why use the UNS-1 at all, at least in areas where there are still conventional routes, when I could just navigate them using VOR radials? The point of the technology is to make your life easier by reducing workload, isn't it?
Even in a modern FMC -- which does this "descent smoothing" for you -- the crew can manually override the vertical constraint at any point for whatever operational reason they see fit, and the FMC will recalculate the descent path based on the new entry. Are you suggesting this is bad somehow? The crew should just revert to mental math if they want or need to do that?
The point is (thank you Avionic) that when making the change, the box isn't behaving as it should. Whether anyone feels I should or should not use the feature, the feature doesn't work properly. Ipso facto.
Thanks,
-R. AKA SlantAlpha -
No need to get bend out shape SlantAlpha, and no need to tell me how FMS (or FMC)/descent profile/and operating aircraft works - been there and I’ve got the tee-shirt, thanks.
Unfortunately, in the real world, pilots have to put up with all that stepped climbing and descending, and inconveniences such as speed control. But I see you just want to try something different in the sim. OK.
If you want to fly the most economical descent profile, why have you not done the most obvious with the UNS 1? Delete ALL the constrains except the one at the FAF, and select the ROD/descent angle from within the menu pages. Sorted;simples.
BTW - I’ve seen the aircraft UNS 1 lose all constrains due to a FFF.
“ the crew can manually override the vertical constraint at any point for whatever operational reason they see fit” LOL… Only if you like tea and biscuits and doing paperwork.
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I'm not talking about overriding it with a value outside of those defined on the chart. I'm talking about overriding a RANGE with a SINGLE -- COMPLIANT -- value, to create a more economical but STILL COMPLIANT profile. Surely you understand that if the range is "at or above 10,000" and I write in "at 13,000" there's no paperwork involved.
And your other thoughts, such as "just delete ALL the constaints," have been duly filed in the appropriate container. Thanks again for your helpful suggestions.
If anyone from JustFlight has some thoughts about whether editing VNAV values in the FMS works as it should, I welcome those.
Sincerely,
-R./SlantAlpha. -
This post is deleted!
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@SlantAlphaAdventures said in Bugs when editing VNAV constraints:
If anyone from JustFlight has some thoughts about whether editing VNAV values in the FMS works as it should, I welcome those.
Your best bet when trying to resolve any issues or ask specific questions is always to contact Just Flight support directly:
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@Derek Thanks. I looked at that page first (https://www.justflight.com/support) but the tone of it seemed like it was more for issues relating to the ordering, download, and installation process. I'll submit these reports there too. Much appreciated.
