In both 2020 & 2024, FSL A321 & PMDG 738, I get a snake between GM437 & GM439.

Does anyone else have this?

https://mega.nz/file/M2t3mS4J#qAWLc3rVuC_ULVaj-84JKjSbt9tYKedS-xjJtoIgcYo

 

Edited July 21, 2025Jul 21 by flyingscampi
Should have mentioned I use the Jo Erlend Sund ENGM

GM437 is mandatory fly over fix.

GM439 is fly-by, but has a QDM of 280 degrees.

Thus, the airplane will have to overshoot the turn from 437, in order to intercept the intended track of 280 degrees to GM439.

Check the procedural paths on the legs-page, verify against the charts (which depicts this snake-shape to an extent) .The actual route depiction might seem odd, but I'd worry less about that esthetic feature if the prior checks have been done 

 

Edited July 21, 2025Jul 21 by SAS443

As @SAS443 explains, this is working as intended.

Just to add an additional point: Consider that at this point, you may already be cleaned up and doing 250 knots IAS, which will result in a pretty large turn radius. At 250 knots TAS (a conservative estimate -- your actual TAS will be slightly higher) and a bank angle of 25 degrees, you have a turn radius of pretty close to 2 nautical miles. Eyeballing from the range rings, the turn radius in the screenshot you provided looks pretty close to 2 miles, i.e. the diameter of the turn (which is easier to eyeball) looks close to 4 miles. So it looks like the FMS is doing a pretty good job of predicting what your actual flight path will look like, given how the SID is to be flown.

1 hour ago, SAS443 said:

intended track of 280 degrees to GM439

Obvious now you mention it!

I guess I could set a manual speed of 220 until GM439.

Yeah, or whatever green dot is. That would tighten up the turn a bit, but it probably won't make a huge difference.

@SAS443 What would you do here IRL? 

2 hours ago, flyingscampi said:

I guess I could set a manual speed of 220 until GM439.

Excellent explanations. 

Something worth mentioning about the speeds, SIDS and STARS are designed to keep the airplane within the protected airspace up to 10K at 250 KTS, with the exception where we have assigned speed limits. Those speed limits are published on charts or are part of the database. There could be a problem with separation when an aircraft is capable of flying at 250 KTS and someone keeps it at 220 KTS without advising ATC of the intentions. 

ATC, during their training, are taught about aircraft capabilities and normal operations, and they plan sequencing according to that or just assign hard speed restrictions. For example, in this case, an Airbus has no issue accelerating to 250 KTS (if there is no speed restriction on the SID), and ATC will expect just that. If you decide to fly at a lower speed without coordination, and another trailing aircraft flies at 250 KTS, spacing can be compromised. 

9 hours ago, martinboehme said:

What would you do here IRL?

Probably be in seat 14A since I am not a commercial pilot. 😁

1 minute ago, SAS443 said:

Probably be in seat 14A since I am not a commercial pilot. 😁

🤣

Somehow had gotten it into my mind that you were...

7 hours ago, LRBS said:

 

Something worth mentioning about the speeds, SIDS and STARS are designed to keep the airplane within the protected airspace up to 10K at 250 KTS

SID STAR are designed to help ATC traffic flow transitioning to enroute to terminal area or vise versa. Not sure why SID STAR should be within 10K? Here is example of one LAX arrival. Check altitude restrictions some of them way above 10K

https://aeronav.faa.gov/d-tpp/2507/00237BASET.PDF

5 hours ago, sd_flyer said:

SID STAR are designed to help ATC traffic flow transitioning to enroute to terminal area or vise versa. Not sure why SID STAR should be within 10K? Here is example of one LAX arrival. Check altitude restrictions some of them way above 10K

https://aeronav.faa.gov/d-tpp/2507/00237BASET.PDF

All I see is that a speed restriction is in effect at LADDY 280 @ FL190, and below 10,000 feet, it's 250. My statement was about the speed of 250 (or whatever is posted) below 10K during SID X STAR. I wasn't referring to altitude crossing restrictions above 10,000 feet. Also, I believe you're aware that 250 KTS below 10K can actually be exceeded in certain conditions, except for the case I mentioned.

19 minutes ago, LRBS said:

All I see is that a speed restriction is in effect at LADDY 280 @ FL190, and below 10,000 feet, it's 250. My statement was about the speed of 250 (or whatever is posted) below 10K during SID X STAR. I wasn't referring to altitude crossing restrictions above 10,000 feet. Also, I believe you're aware that 250 KTS below 10K can actually be exceeded in certain conditions, except for the case I mentioned.

You wrote: "SID/STAR designed to keep the airplane within protected airspace  up to 10k". SID STAR doesn't have to be in "protected" airspace up to 10K as you can see from example above.  Also by "protected airspace" do you mean clear of obstacles?  

1 hour ago, sd_flyer said:

You wrote: "SID/STAR designed to keep the airplane within protected airspace  up to 10k". SID STAR doesn't have to be in "protected" airspace up to 10K as you can see from example above.  Also by "protected airspace" do you mean clear of obstacles?  

I believe the issue here is that you think a SID or STAR is designed solely to "help ATC traffic flow transitioning to enroute to terminal area or vice versa," but that's just one of its purposes. It seems like you enjoy debating about "within protected airspace." Do you truly understand how they are constructed- including their speed requirements during turns to keep you on a desired track, and turn radius to stay within a "protected airspace," not just clear of obstacles? As a CFI, you should know this. Do you realize that besides altitude restrictions, a SID or STAR also has speed restrictions up to 10K feet and above? This constant arguing is getting tiresome. 

 

9 hours ago, LRBS said:

I believe the issue here is that you think a SID or STAR is designed solely to "help ATC traffic flow transitioning to enroute to terminal area or vice versa," but that's just one of its purposes. It seems like you enjoy debating about "within protected airspace." Do you truly understand how they are constructed- including their speed requirements during turns to keep you on a desired track, and turn radius to stay within a "protected airspace," not just clear of obstacles? As a CFI, you should know this. Do you realize that besides altitude restrictions, a SID or STAR also has speed restrictions up to 10K feet and above? This constant arguing is getting tiresome. 

 

The issue is SID STAR is not bound by 10k feet as you stated. Please do define "protected airspace"! Protected from what and protected how? Also as  captain of 747 can you always adhere to 250 kts below 10k?

51 minutes ago, sd_flyer said:

The issue is SID STAR is not bound by 10k feet as you stated. Please do define "protected airspace"! Protected from what and protected how? Also as  captain of 747 can you always adhere to 250 kts below 10k?

I see that your urge to argue and find something is quite strong.

The excess of 250 KTS below 10,000 feet has nothing to do with being a captain on a 747. 

Educating yourself with the FARs, ATC procedures, AIM, and AIP will greatly enhance your understanding of the entire system versus these cheap shots. 

Unfortunately, again, another example of your condensanding behaviour. Very disappointing to see this.

13 minutes ago, LRBS said:

I see that your urge to argue and find something is quite strong.

The excess of 250 KTS below 10,000 feet has nothing to do with being a captain on a 747. 

Educating yourself with the FARs, ATC procedures, AIM, and AIP will greatly enhance your understanding of the entire system versus these cheap shots. 

Unfortunately, again, another example of your condensanding behaviour. Very disappointing to see this.

Cheap shots? You stated incorrect information and can’t even explains it .Spin it anyway you want but all your responses nothing but a distraction. You want me to educated myself ? That is a great response for someone so well informed ! lol Please do educate me ! 

So again SID/STAR doesn’t have to be within 10k as you previously stated.