744 HELP

[Guest navid]

Hello guys sorry if it has been discussed beforeOPT ALT Fl344MAX ALT FL368im flying Fl340, 744 is on Lnav and Vnav, i have 3 hours to T/D and suddenly Vnav changes to FL CH and descends a couple of thousands of feets or even more and climbs slowly back up again for no obvious reason, ALSO, 744 leaves the course and turns right.Please help as i cant do Long Hauls anymore.Thanks

[Guest Boaz]

Are you using Activesky or similar external weather program?Have you noticed any winds or pressure changes?How is your FSUIPC setup, given you have a paid for edition...MAX ALT FL680 is NO GO... I have never seen it!!What is your setup of the aircraft? Loads and fuel? Have you set fuel using FS9s fuel editor or the Queen's own?Boaz...

[Guest navid]

Hello therethanks for quick respondeI am Using active sky, at that moment i had about 40kts tailwind ans there were no change when that happend, not that i noticed, I have the paid edition of FSUIPC, all the settings are the default setting i presume, MAX ALT FL368, my apologiesFuel i started with 220,000 LBS and load was FULL pax, but less than half cargo, (overal less than ZFW), and used PMDG feul,Hope that helps

[Guest Boaz]

I am not sure I am sorry.Have you tried to apply the universal patch again... Simply reinstalling it?Also you might need to backup your files for the queen, and deinstall and reinstall if this doesn't get better.I am blank as if, especially if the airplane enter FL CH, that is really weird.Best of luck...Boaz...

[Guest navid]

I already haveI have reinstalled the whole FS, and emailed PMDG to get a new URL and a fresh install, tried it within the 3 days untill the URL expires, and had the same problem, so within 3 days, i reinstalled again , no hope:-( so in total, 1 FS reinstallation and 2 744s Reinstallation.thanks anyway man

[Guest Boaz]

That sure sounds strange!It can't be some strange joystick or keyboard setting or driver?I grasping for thing air here I know...I think much of the PMDG crew is working to get the 744F readyBoaz...

[Guest navid]

If it was the Joystick 1st it would happen to all A/Cs which it doesnt2nd if it was the joystick, i would fill it as soon as i T/O, or it would happen as soon as i engage Vnav.Thanks once again man

[Guest Ray51]

I had the same problem. For me it was a rudder hardover. Start ASG, go to options and unselect "keep ASG running on auto-submit" This will fix the problem, at least it did for me.Ray

[Guest navid]

>Start ASG, go to options and unselect "keep ASG runningDid you by anychance mean Active Sky by ASG?sorry aboout that man, just dont know what ASG is.Thanks for your reply by the wayRegards

[Guest D17S]

Do a search on the topic "temp sensitivity" in the forum here. What's your airspeed and thrust level when all this is happening? Slow and maxed out, I am guessing. Generally in cruise, a reversion to the pitch mode FLCH means the airplane has slowed down too much and is in the process of saving itself from a stall. In this application, it's an "emergency" mode. You have slowed down too much. I haven't heard of it happening at the OPT altitude, but at a "MAX" alt it seems a common occurance. Also, do you have your AT engaged?As a quick fix, set your EICAS thrust limit to Climb or CON. Cruise power will maintain airspeed at up to MAX altitude in real life, but this is not real life, quite. CLB or CON will give the AT more power to work with (if it needs it). If the "temp sensitivity" pans out (or some version of it), it's likely not a problem with the PMDG model. It may be that the model is just too accurately modeled for its somewhat unreal MSFS enviroment. A shift to FLCH SPD pitch mode in cruise is telling kind of story.

[Guest navid]

You are totally right when the AC has slowed down too much and is going to stall FL CH enables itself, in my case i was cruizing at M0.852 when this happend, engines were on CON mode, as i always leave it on CON, for any unexpected changes in weather, if it is what u say that the model is too accuarate, why i am the only or one on the only persons who had his problem?thanks very much man

[Guest Boaz]

you never leave engine igniters to CON, that is for turb or heavy percip conditions only.Also if you loose speed because of a large increase in tail wind, then go to your THRUST LIM page in your FMC, then select CLB or GA... When the aircraft has begun gaining speed you can revert to CRZ...Also use your FSUIPC to set wind changes of 1 knot/degree per 10+ secs also set baro changes to at least 30 secs a change.This is more realistic and much smoother!Boaz...

[Guest D17S]

Remember that the EICAS thrust limits are only that . . . thrust limits. This is not a thrust setting. It just allows the AT to go to a higher thrust level, but only if it needs it. A cruise thrust requirement at altitude will ALWAYS be a bit less than the EICAS Cruise thrust limit. Look closely. Notice that thrust is just a tad below the EICAS thrust limit horizontal bar on the N1/EPR thrust tape during normal cruise. If thrust is right up against the EICAS thrust limit, you are right on the edge of a 'slow down' crisis. It won't be long now. You should NEVER be right up against any thrust limit in level cruise. You'll notice in these 'over the shoulder' videos that float around that RW pilots generally have CLB set as a thrust limit in cruise. This is why. They want to give the ATs a little more 'room to move', just in case. In the sim, this normally happens at the FMC's calculated 'MAX' altitude. As before, your first indication that something is going wrong is that thrust will be right up against a thrust limit. The AT then 'maxes 'em out' to the current EICAS thrust limit in a vain attempt to maintain speed. This ultimately fails. The airplane still slows down because the max, 'cruise limit thrust' is not enough thrust to maintain speed. "Why" is the $24 question? I expect it is the interface between the model and the atmospheric environment that MSFS is providing. After all, this is a computer game. You sound interested, so let's look into it. First, what's your OAT (outside air temp). Is this SAT, TAT or maybe RAT. What are these and which one would you use to analyze engine performance vs actual results. What's a standard temp at your FL? Should there be a relationship here? Why would . . . how could this matter? Just as a starting point: With just cruise power, maintaining the FMC's calculated mach at the FMC's calculated MAX altitude is achievable in the real world in a real airplane. That's not wrong. It's something else. Maybe it's PMDG's programming of the FMC: or maybe too real a model vs to unreal an environment? We don

[crvm 0]

Easy, simply turn off alll weather and try it that way. If no longer an issue then it's not the plane..................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

[Guest navid]

Thanks to all againD17S, i thought the same, PMDG too real while unreal environment, but if that's the case, why nobody else have this problem? me and a frind of mine are on a RTW trip at the moment (Final Leg) we both used same settings and AS6, i had this problem he didn't. PLUS this happens now in everyflight, ive been using this AC for more than 8 months now i belive, why this problem occured only 2 months ago???The reason i leave my Thrust LIM on CON , is that i have seen everytime Acive sky weather changes, i see the speed reduces, and as i cannot monitor this for evry second in a 12 hrs flight, i leave it on CON, for any dramatic changes in Wind conditions, end of the day it is a Computer Program, so I can not totaly trust it, i know it is not realastic and i have seen Over Shoulder videos, that they leave it on CLB or CRZ, but thats RW and totaly diffrent than AS or MSFS.Thanks very much