PMDG 777 pitches sharply up or down while handflying.

[Delta Captain 0]

I just recently got the PMDG 777 after about a year with the NGX and was immediately impressed save for one thing. I like to handfly my approaches and departures and I immediately noticed that the aircraft would without warning pitch sharply up or down. I never had this problem with the ngx or any other airplane. I thought it might be connected to trim but I disproved that after some experimenting. Is this part of the fbw (I can't imagine it would be) or is it something wrong with my setup? Thanks for your speedy reply!

[Budbud 227]

Hi,

 

First, read the topic below and add your full name accordingly if you want to have a speedy reply, don't want your post to be delete and get a warning.

 

http://forum.avsim.net/topic/458101-signing-posts-in-this-forum-an-overview-for-enforcement/

 

How are your axis configured in fsx? Through the default axis configuration or through fsuipc? What device do you use? Have you configured the pitch trim through buttons up and down (as advised) or through a pitch trim axis (not advised)?

[777simmer 117]

We have had many threads about the fbw system already....maybe the info you need (how to fly the PMDG777, how to calibrate your hardware, etc) is in there already.

 

SP1c has been a big improvement so make sure you have that installed (just open up the operation center, it will tell you if updates are available).

 

When out of trim you do get pitch moments that cause the airplane to accelerate or decelerate back to the trim reference speed (you should display it (CDU option) when you are learning to fly the PMDG777 as it will show you why your airplane is pitching up/down).

Do not mistake the MCP target speed (magenta) for the trim reference speed (blue if option to display is enabled). The airplane will pitch up/down to achieve the trim ref speed.....not the MCP target speed!

 

Large pitch deviations due to being out of trim should only occur when way out of trim (like 20kt or more) and if you let go of the yoke long enough.

 

If you mean by "sharp" that you get sudden pitch changes of instant +/-5 degrees or more then something is wrong and I would start to doubt the calibration of your yoke hardware.

[kaspern83 77]

ive had issues as well, if you are using an asus motherboard there is some kind of real time clock issue which made my  plane do cartwheels mid air. Apparently the pmdg 777 uses the RTC for systems.. I did an bios update seems to have fixed the issue for me for the time being. Not sure if the problem is related.