Sign in to follow this  
asjsouzajr

Strange behavior with Holding Pattern

Recommended Posts

It's very weird what happens with the T7 (200, 300 or Freight) as the Screenshots shows sometimes I get a circle and sometimes I get the normal path, although I do the same procedure.

Does anyone already had something like this ? or at least has an idea of what's going on ?

 

for example during the same flight, same waypoint:

 

fea27049-41fd-4cdf-9a8b-b65aec8ce012_zps

 

3S_working_zpsq5yihhms.jpg

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

even with the same inbound course, sometimes (actually most part of time) I get this situation 

Share this post


Link to post
Share on other sites

 

 


Does anyone already had something like this ?

 

Yes! I've had this happening and I really didn't know why!

 

I think I "solved" it by deleting the hold and creating it again.

Share this post


Link to post
Share on other sites

I also think it is related to the angle of the inbound course to the hold fix. On the first screenshot hold is at DEMAB with no intercept angle while the 2nd shows you have a 10deg inbound angle to SOLVU.

 

Maybe the reason???

Share this post


Link to post
Share on other sites

I'm not really sure if, even if you get an ugly circular pattern as a "preview" on the ND, the plane will actually fly a usual holding pattern.

 

Could you confirm the plane does not fly in circles?


 

 


Maybe the reason???

 

Maybe, but I'd be amazed if that was the actual real aircraft feature. If that was the case, I would consider it then a correct representation of a real aircraft's bug. Something like the "incorrectly regarded as goofs" section at IMDB :D

Share this post


Link to post
Share on other sites

I tested just to see what would happens and the acft just follows the circle (quite ridiculous kkkk).

 

Yes! I've had this happening and I really didn't know why!

 

I think I "solved" it by deleting the hold and creating it again.

 

I'll give a try and report back.

Share this post


Link to post
Share on other sites

u


I think I "solved" it by deleting the hold and creating it again.

 

unfortunately didn't work 

Share this post


Link to post
Share on other sites

Happened yesterday. Saw the circle depicted on the ND about 50 miles prior. Don't recall if it changed shape, in part because I Armed and exited the HOLD without completing a full circuit.

Share this post


Link to post
Share on other sites
unfortunately, nothing I've tried works ...

I think I'll have to live with this problem, because even uninstall and reinstall I've tried

Share this post


Link to post
Share on other sites

 

unfortunately, nothing I've tried works ...
I think I'll have to live with this problem, because even uninstall and reinstall I've tried

 

 

 

Why don't you raise a Support ticket at PMDG and have them investigate?

 

Absolutely! Submit a ticket and have them look into it please!

Share this post


Link to post
Share on other sites

Yesterday I was recording my flight tutorial, and fate had it that the circular holding pattern appeared again on the ND. I let the plane fly into it to see what he did, the circle just got bigger and bigger and LNAV flew straight away. When I couldn't hold it any longer I reverted to HDG SEL and directed the plane into the correct holding pattern (this is good airmanship by the way, instead of trying to figure out what the hell LNAV is doing, I revert to a lower automation mode and regain control of the aircraft's navigation)

 

I think the problem arose when I put a 5 nm LEG into the HOLD page instead of the default 1 min time.

 

I'll describe the sequence of events:

 

1.- First I created the holding pattern at the IAF LOPNA before descent. You can see it in my video here (it's in Spanish, but not really necessary to understand what I say) from 18:18 to 19:37. The shape of the holding pattern looks fine.

Qd9wmm8.jpg

 

2.- Descent starts. The holding pattern looks fine all the way to the waypoint that's immediately BEFORE the holding waypoint, which is DGO.

42mQToj.jpg

 

3.- Exactly when the waypoint hold becomes active after passing DGO, the hold on the ND turns into a circle. You can see how that happens here at exactly 22:23

biMQu0d.jpg

 

4.- Once I reach the hold waypoint and "enter the hold", the circle becomes bigger and bigger until it's huge. See the video at exactly 25:00 once the aircraft reaches LOPNA.

wM7MqaG.jpg

 

 

5.- Finally at 25:42 I have to revert to TRK SEL, the circle becomes smaller again.

cOph02w.jpg

 

6.- Once established on the outbound leg of the hold, I exit the hold and delete it in the FMC. Then I create it again, this time leaving the default 1 min leg. Now it looks fine.

uI77yJA.jpg

 

 

7.- Finally the aircraft flies the hold just fine. Just not with the 5nm leg that I wanted but with the 1min default leg.

F78YOxp.jpg

 

 


I did submit a ticket. Let's see what the support team has to say :)

Share this post


Link to post
Share on other sites

How interesting. Glad you were able to reproduce it. 


 


Keep us posted and what PMDG says about this.


Share this post


Link to post
Share on other sites

I've always believed this to be correct behavior, the path prediction routine has not created a solution for the holding pattern. To support this theory, I point to how the magenta line will shift entering a enroute pattern as wind adjustments, speed, etc., are resolved. Often the patter gets larger or smaller as iterations to the prediction converge.

 

Too much fascination with the magenta line. I think it's pretty cool that the FMS actually does holding patterns.

Share this post


Link to post
Share on other sites

I've always believed this to be correct behavior, the path prediction routine has not created a solution for the holding pattern. To support this theory, I point to how the magenta line will shift entering a enroute pattern as wind adjustments, speed, etc., are resolved. Often the patter gets larger or smaller as iterations to the prediction converge.

 

Too much fascination with the magenta line. I think it's pretty cool that the FMS actually does holding patterns.

 

High Dan. I also think it's pretty cool that the FMC does the patterns. It's a highly non-trivial maneuver. Just the fact that the aircraft has to choose between 3 different types of entries and then perform the entry correctly amazes me.

 

I don't agree with the "too much fascination with the magenta line" bit. This has nothing to do with the classic "Children of the Magenta" discussion, it has nothing to do with being able to fly the aircraft. It's just a bug reporting thread. If the aircraft does not perform as expected, it's good to report it so that PMDG correct.

 

Maybe the OP and me are wrong, but I want to believe that the real aircraft won't generate a "circular" holding pattern which gets infinitely big when the aircraft enters it. I did not wait long enough to see what happened, maybe LNAV did eventually fly the pattern correctly, I just couldn't stand it and reverted to HDG/TRK SEL in a display of "little fascination with the magenta line".

 

Regards! :)

 

How interesting. Glad you were able to reproduce it. 

 

Keep us posted and what PMDG says about this.

 

 

Thanks Mark! I will!

Share this post


Link to post
Share on other sites

No, the real airplane will not do that.

 

Or at least, it should not and I have never seen it.

But that does not mean it cant happen or will never ever happen.

Many things can be coded wrong and these bugs will then be corrected in the next database update.

 

We have had all sorts of bugs in the past......like the aircraft turning in the wrong direction (left instead of right) immediatetely after take off as the SID required a 180 degrees turn to a waypoint behind us.

 

The only thing you can do is revert to HDG mode, and trun/fly as required.

Then, usually when you put the active waypoint on top again, all problems are magically solved.

Share this post


Link to post
Share on other sites

Thanks for your confirmation Rob! As I thought, this must be a bug and can't be something of the real plane.

 

 

 


The only thing you can do is revert to HDG mode, and trun/fly as required.
Then, usually when you put the active waypoint on top again, all problems are magically solved.

 

Which is exactly what I did :)

Share this post


Link to post
Share on other sites

Thanks for your confirmation Rob! As I thought, this must be a bug and can't be something of the real plane.

 

 

 

 

Which is exactly what I did :)

I tried this and it didn't matter what I chose for leg time or distance I got the large magenta circle. However the aircraft did fly the hold as  programmed, only the drawn route was wrong. I suspect the hold racetrack shown earlier is a generic representation. The circle that's drawn when the hold is the next waypoint is an attempt to predict the actual path, but it only shows a circle, not the straight legs that make it a racetrack pattern. The circle was the correct radius for the speed and bank angle in my case.

 

I'm sure this holding pattern path drawing used to work properly before so it may be a bug introduced in the last update. It will be interesting to hear what PMDG say in reply to your ticket.

Share this post


Link to post
Share on other sites

 

 


However the aircraft did fly the hold as  programmed, only the drawn route was wrong.

 

I guess I wasn't patient enough! I was recording my tutorial and didn't want to experiment. On another occasion I might have waited to see what she did.

 

 

 


It will be interesting to hear what PMDG say in reply to your ticket.

 

I will keep you informed! :)

 

Regards,

Share this post


Link to post
Share on other sites

Maybe this happens because the holding entry logic switches from "direct entry with flying the first 180° turn" to "direct entry with bypassing the first 180° turn" (direct turn into outbound leg). Probably the relatively high speed of 250 kts IAS instead of 230 kts IAS (entry speed) while descending further 1000ft inbound the holding fix contributes to this conflicting behaviour...

Share this post


Link to post
Share on other sites

Okay guys,

 

So I got a very polite reply from a member of the team, thanking me for my input and letting me now it will be looked after and fixed for a future update.

Share this post


Link to post
Share on other sites

 

I've always believed this to be correct behavior, the path prediction routine has not created a solution for the holding pattern. To support this theory, I point to how the magenta line will shift entering a enroute pattern as wind adjustments, speed, etc., are resolved. Often the patter gets larger or smaller as iterations to the prediction converge.

 

Too much fascination with the magenta line. I think it's pretty cool that the FMS actually does holding patterns.

 

 

Hi Dan, I appreciate your a beta tester, but I don't think this comment was very helpful. James had spotted a bug, wasn't sure and asked if this was correct behaviour, and your answer seems to imply that he should be grateful that it even does a holding pattern. PMDG pride themselves on their accuracy and attention to detail and I think LNAV and holding patterns are pretty important functions which should work correctly. I'm glad that they will look into fixing it, as if you fly online on Vatsim it helps if your A/C can track a hold.

 

Cheers

 

Neil Waren

  • Upvote 1

Share this post


Link to post
Share on other sites

 

 

 

 

 

 

Hi Dan, I appreciate your a beta tester, but I don't think this comment was very helpful. James had spotted a bug, wasn't sure and asked if this was correct behaviour, and your answer seems to imply that he should be grateful that it even does a holding pattern. PMDG pride themselves on their accuracy and attention to detail and I think LNAV and holding patterns are pretty important functions which should work correctly. I'm glad that they will look into fixing it, as if you fly online on Vatsim it helps if your A/C can track a hold.

 

Cheers

 

Neil Waren

Neil,

 

The sim tracks the hold well enough. It's just the magenta line that is wrong. More or less as Dan said.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this