Going off course, LNAV and heading select.

[UKV2189 0]

Dear all,

 

I've been granted the unfortunate aspect of embarrassment at the hands of the 747-400. I was flying on LNAV when suddenly the aircraft started to turn off course to the left without any warning whatsoever, naturally I disengaged the autopilot almost immediately to turn back on course. I hand flew for another few minutes checking I had set everything up as should be done. After which, I turned back on the autopilot, it was ok for about 5/10 minutes, then it started turning off course again, hand flew for about a minute or so, turned back on the autopilot and then it was about 2/3 minutes before it started turning again, this got more frequent as the flight went on, I got half way through my Atlantic crossing and found myself flying the aircraft for the rest of the 12-hour trip. Not only was I embarrassed that the aircraft was turning off course but being told constantly to turn this heading, that heading, you are off course proceed direct MARGO. I really was having a bad flight. Just before writing this post I took the aircraft up again on a short leg in Japan, again I was faced with the same problem, luckily I was handed to UNICOM before the problems started again. It happens at no specific point in the flight. It's almost like the autopilot wants go into a left holding pattern. No holds we're programmed into the FMC, I checked.

 

I'm going to halt flying the 747 until this is fixed. I might dig out my 757, long time no fly.

 

I will appreciate any help I can get.

 

I don't like my 757 so the less time I spend flying it the better.

 

Kindest Regards,

Craig

[goldy861985 0]

Hi man u ve to perfectly align IRS otherwise its gonna do the same make sure go to overhead panel turn IRS to off then to NAV turn back to align after that when FMC ask u to put IRS location then turn the IRS to NAV on overhead panel after that u r done fly it let me know if its working fine

[UKV2189 0]

Hi man u ve to perfectly align IRS otherwise its gonna do the same make sure go to overhead panel turn IRS to off then to NAV turn back to align after that when FMC ask u to put IRS location then turn the IRS to NAV on overhead panel after that u r done fly it let me know if its working fine

Ah, ok. I turned them straight to NAV. I will just complete my current flight and then try this. Thanks bud.

[UKV2189 0]

The problem is still persistent, after trying a few times the solution above.

 

 

[sddjd 117]

I've been having the same problem for several weeks now.  Been flying the queen for years.  Suddenly several hours into long-haul flights the autopilot will spontaneously disengage and the aircraft will begin flying graceful left hand circuits until fuel is exhausted (or I intervene).  

 

This is extremely frustrating as it's usually several thousand miles into a journey.  No errors or warnings are present (aside form the autoflight disengage tone), but the bird will circle until fuel dry...  :blink:

[1290SASRider 26]

I've only had this happen once, on a ZSPD - PANC leg several hours into the flight when I was experimenting with adjusting the simulation rate.  I was trying the ½ normal rate when it happened.  I restarted the flight, didn't mess with the rate and it went fine; no "excursions."  But no answers unfortunately...

[scandinavian13 5,192]

Using weather add-ons?  If so, which ones, and if they have "modes," in what mode?

[scrunge49 3]

Hi Craig,

 

I had an issue just like this, it turned out to be my flight yoke ( its getting old) spiking through the USB port and knocking LNAV off. I found that for some reason the pmdg 777 was exceptionally sensitive to this ...

[Bill Alderson 24]

I'm having the same problem.  I just upgraded to the FSX version yesterday.  Been flying the FS2004 version for years (most recently last week) and no problems.

 

It seems that the aircraft is to the right of the lubber line on the FMC and the closer I come to a waypoint, the more it wants so veer to the left.  By the time I get to the waypoint, the whole thing seems to be skewed about 45 degrees to the left.  I have to go to the LEGS page direct the aircraft to fly directly to the next waypoint.  It straightens out but eventually does the whole thing all over again.

 

I calibrated my joystick and checked the spike boxes in FSUIPC but still no joy.  As for weather programs, I have Active Sky Next and  I have a registered version of FSUIPC.

 

I'm out of ideas.  :unknw:

[scandinavian13 5,192]

 

 

I calibrated my joystick and checked the spike boxes in FSUIPC but still no joy.  As for weather programs, I have Active Sky Next and  I have a registered version of FSUIPC.

 

Try the Flight1 Registry Repair tool.

[Bill Alderson 24]

Try the Flight1 Registry Repair tool.

 

WOW!  Thanks Kyle!  That did the trick!  I was skeptical but I'm a believer now!  :yahoo:

 

Thanks again.....

[scandinavian13 5,192]

 

 

WOW!  Thanks Kyle!  That did the trick!  I was skeptical but I'm a believer now! 

 

Yeah, I was the same way until I tried it.  It's amazing how simple the fix is, and crazy how something in the registry could cause so many issues.

[asticou 1]

Ok, where do I find the Flight 1 registry repair tool?

 

Regards,

Asticou

[pschlute 37]

Ok, where do I find the Flight 1 registry repair tool?

 

Regards,

Asticou

At the flight1 website library.

[asticou 1]

Thanks, that was the problem solver. Flying now and on course.

 

Asticou