Whereas in the navdata (e.g. X-Plane Custom Data native format) the airway exists:
from LAGEN to TUTIV
from BARPI to LAGEN
BARPI → DAXNU → TUTIV only exists in one direction
so TUTIV is not actually a start fix for M859
So there’s a small error, but also, the information provided by charts doesn’t indicate direction at all, so we cannot know which segments can be flown in which direction (the former inaccuracy is probably simply a result of Charts attempting to fit the information into a single entry per airway).
I suppose you could have one entry per airway, but in the resulting information panel, under “Fixes”, listing for each segment:
in which direction(s) in can be flown
the associated altitude boundaries for each direction
(which aren’t necessarily the same in both)
the odd/even rule for the segment of that particular airway
(IIRC that’s also part of the info available in the navdata)
I imagine it might be easier, or at least quicker, to implement two entries per airway, one for each direction, when available.
Currently it only shows the pair of fixes, but does not indicate whether it can be flown one way (RESMI → COHPA), the other way (COHPA → RESMI), or both.
Also, while I don’t have a specific example in mind, IIRC, sometimes the altitude limits can be different depending on which way you’re going (A → B vs. B → A).
BTW I just used UM729 as an example here, as that airway is actually unidirectional, from UNKIR to RESMI, and cannot be flown from RESMI to UNKIR at all…
Currently, Navigraph Charts does not offer any directionality information at all regarding airways and seemingly selects the start and end fixes randomly, resulting in the issues discussed:
indicating UM729 as from RESMI to UNKIR
when it’s actually only available from UNKIR to RESMI
indicating M859 as from TUTIV to LAGEN
when it’s actually available
from LAGEN to TUTIV in one direction
from BARPI to LAGEN in the opposite direction
(i.e. bidirectional between BARPI ↔ LAGEN
but unidirectional from BARPI → TUTIV)
Due to the lack of direction info, there are probably dozens if not hundreds of small issues in the way Charts currently presents airways.
The vertical limits on a per-direction basis and the even/odd rule information being only “bonus” info which would be good to have in an update that fixes the lack of direction information currently available in the app.
On this screen, “Fixes” should say “Segments”. We should also include some sort of visualization to make the directionality constraints clearer. Maybe we can use arrows here too! We’ll investigate.
Regarding “vertical limits on a per-direction basis” and the odd/even information, this is information that the Charts app currently does not have access to. We have a long list of wished-for features, and this is definitely not high up on that list, but I have noted it internally, regardless! It seems like we have discussed it before and want to do it at some point.
Regarding the title of this topic: The directionality is shown in the map. We shall make an effort to make this clearer in the menu as well! I’ll save a reference to this topic along with the internal report and will let you know when we fix this.
and seemingly selects the start and end fixes randomly, resulting in the issues discussed:
