Wierd LNAV behaviour?

[777 340]

Ok this may sound odd, but this is like the 4th time its happened, LNAV is fine until it reaches a  waypoint, suddenly, it veers off course, and altitude decreases, however A/P is engaged.I then disconnect the A/P to correct the issue then with manual controls, the aircraft rolls forward and is uncontrollable,as if I was slewing, when i'm not. Then all kinds of warning ring as the aircraft smashes into the virtual ground doing barrel rolls forward all the way down..  Any Ideas????.

I am using ASN, and planning the route using Simbreif. But like all problems this has only suddenly happened, most recently today, just before TOD after a 3 hour flight. There were thunderstorms in the area, but on the other 3 occasions it was during climb and no adverse weather conditions.

[scandinavian13 5,192]

Any Ideas????.

 

Hardware trim axis?

[777 340]

Hardware trim axis?

 

 That could be the control issues, but why does the LNAV veer off course? I use A joystick with buttons assigned to elevator trim.

[scandinavian13 5,192]

That could be the control issues, but why does the LNAV veer off course? I use A joystick with buttons assigned to elevator trim.

Disregard.

 

Do you have an ASUS motherboard?

[777 340]

Disregard.

 

Do you have an ASUS motherboard?

 

 Nope Intel DX58SO.

[scandinavian13 5,192]

Nope Intel DX58SO.

Hmm...sounds like a BIOS clock issue.

[777 340]

Hmm...sounds like a BIOS clock issue.

Seriously ??? I mean have an OC...but like I said never happened before....Making my VA flights.....non flyable..

[scandinavian13 5,192]

Seriously ??? I mean have an OC...but like I said never happened before....Making my VA flights.....non flyable..

Depending on the stability of the OC, it could be the issue. Our software is dependent on the HPET. If that starts getting a little out of sorts, you'll see weird stuff in any program. It's just a lot more visual on our stuff since we're using a higher precision clock.

[777 340]

Depending on the stability of the OC, it could be the issue. Our software is dependent on the HPET. If that starts getting a little out of sorts, you'll see weird stuff in any program. It's just a lot more visual on our stuff since we're using a higher precision clock.

Very interesting, will mess around and try disabling the HPET. See how it goes.

[scandinavian13 5,192]

Very interesting, will mess around and try disabling the HPET. See how it goes.

Disabling the HPET isn't going to help you. Our code depends on that. I'd knock the OC out to test it out first.

[777 340]

Disabling the HPET isn't going to help you. Our code depends on that. I'd knock the OC out to test it out first.

Ok will try lower the OC, having said that, I have been running FSX on the same OC for years,with the 777,also P3d, for a good few months and all was well .I don't believe is a hardware problem. Thanks for the help though.

[downscc 1,327]

 

 

I have been running FSX on the same OC for years,with the 777,also P3d, for a good few months and all was well

 

Check for dust in your filters? I'm always finding dog and cat hair in the most unlikely places.

[scandinavian13 5,192]

 

 

I don't believe is a hardware problem.

 

Just a word of advice:

If you're asking people for help, it's best to try what they say and avoid questioning it, at least outwardly...particularly when product support is that person's job. It's kinda rude.

[PMDG777 231]

 

 

I don't believe is a hardware problem. Thanks for the help though.

 

If you ever run into issues with software, your best first bet is to always return to stock clocks on CPU, GPU & RAM before continuing. Something like an unstable OC isn't going to be fixed by software. Just because it was stable x long ago, doesn't mean it will remain to be stable.

[777 340]

Just a word of advice:

If you're asking people for help, it's best to try what they say and avoid questioning it, at least outwardly...particularly when product support is that person's job. It's kinda rude.

 

 I do understand, I have worked in a customer support environment for some years. I'm not being rude, just questioning the advice given. As a paying customer, I also believe i'm entitled to my opinion, be it right or wrong. Once again,  as I said , thanks for the help and assistance from all. Lowering the OC seems the only way to proceed.