Jump to content

Obvious reasons why I wouldn't have had a TOD marker, snowflake on descent, etc.?


Recommended Posts

Just finished my first complete flight - very satisfying! Not entirely without issue though. Had to restart with the escape-key-kills-engines-mid-flight bug (not specific to CRJ, something with MSFS). Then getting acclimated to the workload of getting the thing setup, aloft, managing speed, all that. So it's possible I rushed or missed some key step here.

 

I never saw a TOD marker in the flight plan, nor at any point did I get the snowflake and blue ball for descent profile. Just had to wing it. I know I've had it work successfully on a previous flight that I had to cancel out of, so I'm trying to think of what I might have missed.

 

Had the flight plan together, no discontinuities, that all worked fine. I am certain I had the cruising altitude correctly input as FL320 in the FMS, and it showed a 3 degree path angle. I was in NAV mode guided by FMS the whole time. Any thoughts of some critical piece that may not have been done that's a prereq for getting the profile to work?

 

 

Link to comment
Share on other sites

I had exactly the same experience today.  Previous 5/6 flights have been absolutely fine - today, flying MYNN to KPBI, no TOD...  I don't think I did anything differently so cannot think what it could be.  Was unable to find anything in the manuals either.

Link to comment
Share on other sites

I'm also experiencing this.

All worked well in the tutorial flight but when using a custom route I get no TOD, no blue ball/ snowflake during the descent either. I've checked the altitude is entered correctly in VNAV and a destination runway is selected but it doesn't seem to correct the issue.

Is there an option that needs selecting in the EFB or maybe i'm missing something in the MCDU.

Link to comment
Share on other sites

Likewise, unless I'm missing something I'm fairly certain I've got the cruise alt and destination runway set. But, I'll walk through my typical process.

 

First, POS INIT entering my origin airport, and copy that lat/long down to current location. Moving to flight plan I enter the origin airport, destination airport, alternate airport, and originating runway. I'll enter en-route waypoints, then go to the departure / arrivals page and select my destination approach (e.g. ILS36R), the STAR, and transition. Execute that, go to LEGS page and clean up any discontinuities, execute that. Then in VNAV I'll set my cruise altitude to be whatever it is for the flight plan.

 

So as far as I can tell I've entered the necessary information. I will add that I intentionally avoid entering a SID as I know there's a bug with waypoints coming in out of order. Not sure if that's relevant.

 

But no TOD appears nor any profile information on descent. In TheDude's tutorial it shows how having the wrong cruise altitude winds up resulting in an inaccurate TOD point. But in my case, there's just no TOD point nor descent profile whatsoever.

Link to comment
Share on other sites

2 hours ago, jerseytom said:

I will add that I intentionally avoid entering a SID as I know there's a bug with waypoints coming in out of order. Not sure if that's relevant.

I think it is. I didn't have the snowflake either when I had no SID. I didn't have one because the airport doesn't have any.

Link to comment
Share on other sites

7 hours ago, Thx1137 said:

I think it is. I didn't have the snowflake either when I had no SID. I didn't have one because the airport doesn't have any.

I think you might be onto something. The route I was flying didn't include a SID either as the departure airport doesn't have any.

Is a SID required to get the TOD marker and descent profile to show?

I'll do a test flight later and see if adding a SID fixies this.

Link to comment
Share on other sites

Did you have any altitude constraints at one of the waypoints? Those will come with a SID, but you can also enter one manually, e.g. 3000ft at final fix before runway. 

Link to comment
Share on other sites

39 minutes ago, TheFly77 said:

Did you have any altitude constraints at one of the waypoints? Those will come with a SID, but you can also enter one manually, e.g. 3000ft at final fix before runway. 

 

I can say that I have had altitude constraints in my flight plan, as part of the STAR, but again I've been avoiding SIDs. And with the speed and altitude constraints on the STAR there was no TOD or descent profile.

Link to comment
Share on other sites

There needs to be an altitude constraints on the descent. You do not need to enter a SID. Just enter an altitude constraint on one of the waypoints on the descent (if I'm correct from the top of my head, enter altitude and then select button on right side of the relevant waypoint in the legs page)

Link to comment
Share on other sites

Right. I'm saying - I already had a variety of altitude constraints on the descent, as automatically brought in by the STAR and ILS approach. But even with that, no TOD nor descent profile.

Link to comment
Share on other sites

2 minutes ago, jerseytom said:

Right. I'm saying - I already had a variety of altitude constraints on the descent, as automatically brought in by the STAR and ILS approach. But even with that, no TOD nor descent profile.

Same here. The STAR already had predefined altitude contraints when entered into the CDU. No TOD or descent profile was vissible on the MFD nor did it give me a top of descent in the MFD VNAV setting.

Link to comment
Share on other sites

I did. Cruise alt was set in the CDU under Perf init as per standard. Also double checked in the Vnav pages and it was set.

 

I just did the following flight and the TOD appeared KMCO/36R MCOY2 MLB ANNEY4.MLB KMIA/30

 

Note it has both a SID and STAR. My previous route had no SID available at the departure airport and didn not show a TOD.

Link to comment
Share on other sites

1 minute ago, jerseytom said:

@Traikus What would be interesting would be if you re-did that flight but just didn't select the SID. Like KMCO/36R DCT MLB ANNEY4.MLB KMIA/30

Thats my next trip this evening. I'm thinking its the lack of a SID.

Link to comment
Share on other sites

Quick update as I've just flown the same flight as above but omitied the SID KMCO/36R MLB ANNEY4.MLB KMIA/30

Even with no SID i had the TOD marker and all expected descent profile info, so I'm at a loss as to what i'm doing wrong.

It seems to be certain routes that fail to generate a TOD and can not find a cause. I'll try a few other short flights and see what happens but I have a feeling it could be linked to transition altitude. If the flight is lower than the trans alt the TOD doesn't seem to appear.

Link to comment
Share on other sites

11 minutes ago, Traikus said:

Quick update as I've just flown the same flight as above but omitied the SID KMCO/36R MLB ANNEY4.MLB KMIA/30

Even with no SID i had the TOD marker and all expected descent profile info, so I'm at a loss as to what i'm doing wrong.

It seems to be certain routes that fail to generate a TOD and can not find a cause. I'll try a few other short flights and see what happens but I have a feeling it could be linked to transition altitude. If the flight is lower than the trans alt the TOD doesn't seem to appear.

 

The next time you notice that there's no TOD point go to one of your downstream waypoints and put in an altitude constraint manually. See if that changes things. 

 

Sometimes what we think are altitude constraints aren't actually constraints. They're just altitudes the FMS thinks we should be at at that waypoint. In the real airplane the FMS uses slightly different text sizes to show us whether it's an actual constraint or not but that doesn't seem to be modelled in the Aerosoft CRJ.

 

Anyway give the manual constraint a shot and see what happens. 

Link to comment
Share on other sites

5 hours ago, Chaxterium said:

Sometimes what we think are altitude constraints aren't actually constraints.

A "constraint" would be an Above and/or Below constraint wouldn't it? It is something "you have to do".

Just having an altitude in the legs page I think is advisory. Sure a 737 or something would follow it but it isn't actually a "constraint" in my mind. That doesn't mean I'm right though.

Link to comment
Share on other sites

39 minutes ago, Thx1137 said:

A "constraint" would be an Above and/or Below constraint wouldn't it? It is something "you have to do".

Just having an altitude in the legs page I think is advisory. Sure a 737 or something would follow it but it isn't actually a "constraint" in my mind. That doesn't mean I'm right though.

Just entering an altitude (with no A or B is indeed a constraint. In this case it means you have to cross the waypoint at exactly that altitude - no lower, and no higher.

 

One important thing to insure you get a TOD is to be sure there are no open discontinuities anywhere on your LEGS page.

Link to comment
Share on other sites

I think I've found it, following @Chaxterium's suggestion. Still don't understand what's going on exactly or if this is expected behavior.

 

The route, for those following along at home: KSAV/10 DCT JROSS DCT FLLGG STOCR3 KCLT/36R, cruising at FL250. Short flight, like ~40 minutes in the air.

 

If we pull up the STOCR3 approach plate, when heading towards 36R there is a constraint at GATEE: 210 kts, 6000 feet. I can confirm, as shown below, that this automatically came in when I picked the STOCR3 approach. This was also after I set FL250 as my cruise altitude in VNAV, and from the down arrows there on the legs page it seems to know that all of this is descent phase. I can also confirm (not extensively shown below) that I cleaned up the discontinuities getting into the STAR, and from the STAR into the ILS approach. So all good there.

 

Please login to display this image.

 

So I get up, fly, get into cruise, get into what it seems to think is the descent phase... but no blue ball nor snowflake, no TOD marker, none of that. So I say whatever, I can get the rate I need to get down from the VNAV DESC INFO page and start doing that.

 

Please login to display this image.

 

Just for grins though, I go to my legs page and I just type over the constraint at GATEE. It already says 210/6000, I type in 210/6000, enter it, and execute.

 

Ta-da! Snowflake etc. show up and I have my profile (not shown, was too excited to take a screenshot). Followed it the rest of the way down.

 

So the question is - is this expected functionality? It seems hard to imagine it is. When I typed over the 210/6000 there was no font size change or anything that I could see. Literally just writing over it and executing, and I got my descent profile. 

Link to comment
Share on other sites

1 hour ago, JRBarrett said:

Just entering an altitude (with no A or B is indeed a constraint. In this case it means you have to cross the waypoint at exactly that altitude - no lower, and no higher.

Thanks, though I thought those had bars on top and below the altitude. Maybe I'm thinking of charts as opposed to FMS?

Link to comment
Share on other sites

36 minutes ago, Thx1137 said:

Thanks, though I thought those had bars on top and below the altitude. Maybe I'm thinking of charts as opposed to FMS?

Yes, on charts, a hard altitude constraint will be a single number with a bar above and below. 

Link to comment
Share on other sites

7 hours ago, jerseytom said:

type over the constraint

 

Interesting observation! Almost like it's causing the VNAV path calculation to 'refresh' and as a result you see TOD... Will try this next time I fly and encounter this for sure.

Link to comment
Share on other sites

So can we say this is a bug then? Chart I referenced earlier shows a hard speed and altitude constraint. It appears to come in that way to the FMS when picking the STAR. But it seems to only be recognized as such when you type over it, even with the exact same information.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Privacy Policy & Terms of Use