777 Elevator Question

[paulyg123 135]

I am trying to see if I have a yoke problem or it is just the way the 777 works.

 

When I am getting low on an approach and very slow (I know bad pilot Pauly), if I pull back the yoke to climb, the elevators go only a fraction past neutral (per the flight control display).  It is not until I gain speed will it give me full motion.  Similarly, sometimes I go into a steep climb and I am jamming the yoke forward to level off, but I don't get any input past neutral for 10-15 seconds (thus I am 3 - 5000 feet above what I want -It was similar of the recent A320 accident where the pilot suddenly climbed at 60000 ft/min then stalled).  This only happens when I get sloppy.  Normally the yoke input allow for full range of elevator motion.  Does the 777 restrict the output to keep it inside the safe flying parameters?  or does my yoke need to be replace?  or do I need more training?

 

 

[kevinh 409]

This is to do with FBW trim speed and the way PMDG have reduced elevator authority to enhance out of trim control feel. The only way to avoid running out of elevator control is to ensure you are always in trim for the speed you are flying at.

[wde12 19]

Paul, you're not alone. I've had this same issue a few times and thought it was my hardware and/or another limitation of geeking out at a computer versus the real thing. I then noticed the FBW trim indicator was way off, just like Kevin above mentioned.

[paulyg123 135]

OK, thanks,I noticed tis happens when I am the dangerous yellow zone on the speed tape, it also happens if I am doing a quick flight and never set up the V#'s on the FMC.

[77west 139]

 

 

OK, thanks,I noticed tis happens when I am the dangerous yellow zone on the speed tape, it also happens if I am doing a quick flight and never set up the V#'s on the FMC.

Try turning on the Cyan FBW trim ref bug.

[paulyg123 135]

I am re-visiting this question, because I just added a new yoke and I still occasionally have this problem.  Now I know it is not a yoke issue, but a FBW issue.  I guess the key is to control your speeds and climb rate and don't expect a quick correction. 

 

So how do you turn on the CYAN FBW trim ref bug? What does this mean?

[scandinavian13 5,192]

 

 

Now I know it is not a yoke issue, but a FBW issue.

 

Issue, or lack of understanding...?

 

 

 

So how do you turn on the CYAN FBW trim ref bug?

 

The same spot you turn on all of the realism options in our aircraft:

MENU Key > PMDG SETUP > SIMULATION

 

 

 

What does this mean?

 

It places a bug on your speed tape, just like a Vspeed bug, so that you can see how the FBW has the aircraft trimmed.

 

Long story short? Trim as you should and you won't have a problem.

[777simmer 117]

kevin and Kyle said it.

 

You need to be in trim or else the reduced elevator autority effect makes it allmost impossible to fly.

 

Especially if you are far out of trim (more than 20kt) the problem becomes really noticable. Your yoke feels the same as allways (no force feed back) so your natural tendency is to push/pull slightly on the yoke to correct your attitude. But due to the reduced authority, nothing happens. In the mean time your attitude stays the same and your out of trim problem grows bigger. The yoke still does not feel heavier (no force feed back) so you still naturally react as allways and try to correct with just a little more yoke deflection.....but nothing happens. Untill you give more than 3/4 forward/backward yoke deflection......only then will your attitude finally correct. (thats on my yoke!)

 

I allmost allways fly with the FBW trim speed indicated and recommend everybody to have it displayed.

 

If you do not have FBW trim speed displayed you have to realy realy realy stay on top of what your attitude does and when you accelerate/decelerate be ready to trim at the slightest unintentional pitch change. Dont get distracted by anything or you will be more than 20kts out of trim in no time (cause you dont feel this).

 

Thats not easy when you are flying IFR (VFR with the bigger horizon is do-able)

We have no force feed back on our yokes, so by the time we notice we are out of trim, we are so far out of trim that you are all over the sky thinking what is wring with my flying?!

 

Or at least, that is how it is with my Saitek Cessna Yoke.

Maybe other yokes handle this reduced elevator authority effect better.

[paulyg123 135]

OK, I got it now.  Gee I never knew that one before.  I guess you aim to keep the BLUE FBW tick by your speed and just trip accordingly.

 

Now is this a realistic 777 function found on the 777?  (or a PMDG thingy)  I never noticed it during my 5 hours in the a full motion 777 sim.

[777simmer 117]

Yes....allways keep FBW trim ref indicator at ACTUAL flown speed.

(Actual speed is not to be confused with the magenta speed bug. Ofcourse the speedbug is your or the ATs target, but when the speed bug is set for one speed and you are a few knots of target, just hit that blip trim function real quick so you are trimmed for actual speed).

 

No, the reduced elevator control authority behaviour is not realistic.

As you have noticed in the real 777 sim it is actually a realy realy easy airplane to fly, trim and control. What makes all the difference ofcourse is Force Feedback (that and a few more dollars).

The lack of Force Feedback had PMDG look for other ways to five us an idea that you are out of trim.....they opted for reduced elevator (yoke) authority when out of trim.

[paulyg123 135]

Rob:

 

Thanks for your repies.  You helped me learn a lot here and  I really appreciate it.