I tried several attempts to cross Atlantic in both CJ4 and FBW 320 mods. Both times 3/4 way through airlanes deviated  (autopilot) from planned course (aka magena line) for more than 40 miles and 20 degrees. I tried to manually correct it and then re-engage lateral navigation but both airplanes just was straying further from course. Both routes were generated by default MSFS planner at high altitude . I see correlation between both mods and perhaps MSFS internal navigation/planning. Could anyone confirm and find way around this problem?

Edited December 6, 20205 yr by sd_flyer

My sim would never run that long without a crash to desktop. I was lucky to get an hour flight today. 

The longest flight I've done us about 5 hours east across the Aleutian Islands.  I haven't seen an issue with the AP while doing this.

I did see one post on the official MSFS Forum saying that the aircraft might follow a 'great circle' course as expected but that that Garmin draws a straight line, resulting in an apparent cross track error on very long flight plan legs where the difference between the great circle and the straight line would be large.

LittleNavMap might be a good way to check this and if it's true, a ZenDesk report might be warranted.  

Also if it's a 'great circle' vs 'straight line' error, based on the geometry in play there I would expect the error to reach a maximum around the center of the leg and then start to decrease on the other side, such that you are back on track at the destination waypoint.  

Edited December 6, 20205 yr by marsman2020

2 hours ago, sd_flyer said:

I tried several attempts to cross Atlantic in both CJ4 and FBW 320 mods. Both times 3/4 way through airlanes deviated  (autopilot) from planned course (aka magena line) for more than 40 miles and 20 degrees. I tried to manually correct it and then re-engage lateral navigation but both airplanes just was straying further from course. Both routes were generated by default MSFS planner at high altitude . I see correlation between both mods and perhaps MSFS internal navigation/planning. Could anyone confirm and find way around this problem?

which airport pairs and were you in normal speed or running the sim faster?

I managed a 6 hour flight in modded A320 ok but it was on a South to North route up Africa. In real time, not sped up. That was prior to the current update though. AP tracked flight plan correctly to each waypoint.

AP flying a direct line and not a great circle could be a possible issue (bug) if waypoints are very interspersed. But if it is outright missing waypoints, that is a broken AP either way.

Edited December 6, 20205 yr by RaptyrOne

I'd be interested to try this (likely with a sim rate speed-up) but I have no experience with any of the jets and their more-complex FMC systems vs the Garmin based units.

Could try the Longitude with the G5000 with unlimited fuel turned on....

Edited December 6, 20205 yr by marsman2020

After crossing the Atlantic Ocean, the first thing Charles Lindbergh said after landing in Paris: "My FPS was terrible. My autopilot didn't work properly. And my controls were too sensitive."

  

40 minutes ago, David Mills said:

After crossing the Atlantic Ocean, the first thing Charles Lindbergh said after landing in Paris: "My FPS was terrible. My autopilot didn't work properly. And my controls were too sensitive."

 

A 1920s prop can cross the Atlantic but 100 years later a virtual aircraft in a sim can't without crashing. Progress :) 

9 hours ago, Flyfaster_MTN002 said:

which airport pairs and were you in normal speed or running the sim faster?

I was trying New York to Dublin and no I didn't use acceleration. Everything was in real time

I flew the 182 across with stops in Goose Bay, 2 in Greenland, Iceland and Faroe Islands, over a 3 day period in real WX conditions a month or so back. Lots of icing made me turn back twice. But I made it all the way to Sweden.

Currently just arrived in Queenstown in NZ, I set off from the UK early Sept via Iceland, Greenland, all the way down the east coast of USA to the carrabean into the northern part of South America then all the way up the west coast up to Alaska then across the Alcuciun Islands heading west to Japan, Hong Kong then down to Oz and across to NZ, all done in real time, with real weather which works by the way and no ctd, the simulator is awesome, I have had no problems whatsoever and I have no complaints either,  I love it, been simming for over 20 years, never ever seen anything like this on a desktop simulator, it beats them all BIGTIME,  the scenery what I have seen is breath taking at times, sunrises, sunsets....quite an experience! Heading back to the west coast of the USA now over the Pacific via all the little islands to Hawaii then onto mainland USA, prob touching down in one of the main cities, and its all being flown in the TBM 930.....love it!!!

Regards

Paul EGCC

No problems here with the Longitude (set to unlimited fuel) and the 'IFR High' plan generated by the in-sim flight planner.  The deviation at the end is due to the arrival STAR not being exported into the PLN/picked up by LittleNavMap.

I remember having a similar problem above the Bering sea coming from Alaska, at some point the nav suggested to turn around and go the other way around the globe to Japan, no thanks, changed to manual heading till it fixed itself after a hundred miles or so.

16 minutes ago, EmaRacing said:

I remember having a similar problem above the Bering sea coming from Alaska, at some point the nav suggested to turn around and go the other way around the globe to Japan, no thanks, changed to manual heading till it fixed itself after a hundred miles or so.

There is a glitch in the Pacific where the line drawn on the GPS doubles back at the 180 degree longitude line, but if you leave the AP on the aircraft follows the correct path.  It's just a visual error in the line drawn on the Garmin.

So here is mine another attempt as we speak. I will let it fly and see what happens