747 400X loosing track

[Guest Mad40]

747 400X in FSXAt 1368nm in a flight from WIII to YSSY at FL360 under FMC control LNAV & VNAV Flight was going fine then all of a sudden aircraft started turning side to side at full bank angle heading off coursedisengagged auto pilot and reingaged it but only made it worse checked FMC and flight was still active and in usehave flown this route 2 times before with no problemswas online VatSim with FSInn all fuel and paylosd was done with PMDG programany ideasDarryl Ashlin

[jobepilot 7]

What weather setting/program do you have ??

[Tabs 2,790]

Yeah I'd look at the weather (wind and pressure mainly)... also why isn't your altimeter set to STD (should always be above transition altitude)? you've also got a fuel system misconfiguration warning on the EICAS too.

[Airbrakes 0]

Check the Legs page on the FMC to make sure you didn't miss a waypoint. If you didn't miss a waypoint, press 1L LSK to drag the next active waypoint and the corresponding waypoints to the scratchpad, then again press 1L LSK. Press 6R LSK to activate, then press the execute button. If issue persists, disengage the A/P and cycle the FDs off/on to clear the FMA. Then select VNAV, LNAV, and CMD. If the issue still exists, check the status synoptic page on the Lower EICAS for any off the wall control surface movements that could be related to joystick noise.If your issue is a incorrect or off the wall WX, then a quick reload of the weather should fix it.Although this may or may not help your issue,1) Set standard pressure on the altimeter by pressing on the center of the 'Baro' knob on the EFIS/MCP.2) Cut off hydraulic power to the landing gear by placing the lever to the off posn.3) Turn off the NAI/WAI. It's not needed when the SAT is -40c and colder as ice particles don't adhere to the aircraft.4) Turn off the fuel crossfeeds and the tanks 2 and 3 forward/aft override switches to clear the EICAS message.

[Guest Mad40]

What weather setting/program do you have ??

Thought i nipped that one in the but - was running FSInn /VatSim weather but it caused another problem of +34 deg C at FL350.so now i am trying REX (Real Enviroment Xtreme)seems funny that i flew from KLAX to YSSY yesterday off line in Single player no probs using REX real world weather.Darryl Ashlin

Check the Legs page on the FMC to make sure you didn't miss a waypoint. If you didn't miss a waypoint, press 1L LSK to drag the next active waypoint and the corresponding waypoints to the scratchpad, then again press 1L LSK. Press 6R LSK to activate, then press the execute button. If issue persists, disengage the A/P and cycle the FDs off/on to clear the FMA. Then select VNAV, LNAV, and CMD. If the issue still exists, check the status synoptic page on the Lower EICAS for any off the wall control surface movements that could be related to joystick noise.If your issue is a incorrect or off the wall WX, then a quick reload of the weather should fix it.Although this may or may not help your issue,1) Set standard pressure on the altimeter by pressing on the center of the 'Baro' knob on the EFIS/MCP.2) Cut off hydraulic power to the landing gear by placing the lever to the off posn.3) Turn off the NAI/WAI. It's not needed when the SAT is -40c and colder as ice particles don't adhere to the aircraft.4) Turn off the fuel crossfeeds and the tanks 2 and 3 forward/aft override switches to clear the EICAS message.

Thanks Will have a look at it and see what i can find

[jobepilot 7]

I had a big problem with Fsinn's weather and 35+c @ FL330, it was Fsinn, a known bug. But like you I now use, either Rex, ASA or ASX, Rex seems good. ASA has problems right now but they are working on them. Good luck

[Guest Mad40]

Reloaded flight KLAX to YSSY where I hade the problem only took about 10 minutes to come back funny enough right after Rex updated weather so I pressed 1L LSk and Pressed 1L LSK again then pressed EXC and Back on course and level flight.then around 10 mins later bang all silly again same steps 1L LSK, 1L LSK, EXC then no more problems all the way to YSSY 1783nmThanks THBatMan8 for all the other pointers I now see why to turn off the cross feedsThanks for the help slowly sorting it out. Darryl Ashlin