Still Trim issues with Sp1b

[martin-w 3,234]

The way your carrying on you'll get the thread locked instead of allowing continued mature discussion.

 

Conversely, the way we respond to Bruce's comments might get the thread locked too.

 

If we refrain from overreacting, all will be well. :smile:

[pete_auau 1,152]

Now I'd realize that there is still something very wrong with the trim system but I'd like to kind of sweep it under the rug and pretend that it works perfectly, despite customers repeatedly telling me it wasn't fixed, because I'd rather just ignore it for now and maybe eventually fix it in a SP1C patch down the road. Perfection is consuming!!!

Have you submitted a support  ticket  in yet

[scandinavian13 5,192]

 

 

I'm a rube, Kyle, that's for darn sure, and you are right in calling me out.     The fact is that if I had tried to to program something like a 777 FBW system for FSX myself, I probably would have accidentally released a C* control law system like the Airbus that autotrims instead of the 777 C*U that requires conventional manual trimming.     I mean, we can just assume I'd do something stupid like that with my inexperience, right?    
 
And then, with my fledgling programming skills and superficial knowledge of aerodynamics and physics, it would have probably taken me another entire year to get it 'right'.     Then of course I wouldn't get it right, and I'd probably do something stupid like accidentally reverse the trim reference speed function and have to release a SP1B patch since I really couldn't be bothered with testing the original fix that took me a year to get right in the first place.     I'm a busy person!    Please don't judge me!
 
Now I'd realize that there is still something very wrong with the trim system but I'd like to kind of sweep it under the rug and pretend that it works perfectly, despite customers repeatedly telling me it wasn't fixed, because I'd rather just ignore it for now and maybe eventually fix it in a SP1C patch down the road.     Perfection is consuming!!!    I need to work at a relaxed pace with plenty of vacation time and  without troublesome customers breathing down my neck all the time, whining about it not working right.     
 
Thanks for setting me straight.     I've never fully embraced what PMDG is up against in this merciless business of FSX add-ons, and I will fully admit that I could not handle it personally.     My hat is off to them and I see the whole situation in another light now.  

 

Your assertions of their errors masked by using references to yourself are thinly veiled, amateurish, and really just petty, honestly.

 

If you believe you can do it better, submit a resume and how you can help them.  Otherwise, I'd stop mouthing off.  If you have an issue and haven't submitted a ticket yet, I would also stop mouthing off.

 

That's just me, though.  You're welcome to continue.  I'm appreciating the entertainment...

Have you submitted a support  ticket  in yet

 

Doubtful...might as well just complain about it here endlessly, and assert that they're being dubious.

 

If he submitted a ticket and PMDG responded, it would erode his stance that they're evil, money mongers.

[martin-w 3,234]

I guess my suggestion that we don't overreact to his posts fell on deaf ears.

 

Arnold Bruce's posts by themselves won't get this thread locked, but the way some of us choose to respond to them will.

 

It happens all the time here. I know it's tempting to admonish, as if the poster was a naughty child, but it serves only one purpose, to destroy the thread.

 

Another forum member overreacted first, followed by Kyle, Bruce responded, as you'd expect, Kyle escalates it further and now it all goes tits up.

 

PMDG are perfectly capable of defending themselves. They don't need us to admonish those we perceive to be wrongdoers.

[scandinavian13 5,192]

 

 

PMDG are perfectly capable of defending themselves. They don't need us to admonish those we perceive to be wrongdoers.

 

I approach it from a more humanistic level.  I wouldn't go into any developer's forum and start accusing them of wrongdoing unless I could prove it as fact.  Further, I wouldn't say a word about an issue until I've raised it to them first (not sure if he has or not - just a point to be made).

 

Ready for new code, as you see fit, though... 

[aceridgey 330]

It my be misunderstanding but this is what I have gauged from  flying along with a real pilot.

 

If one pushes the aircraft out of trim using the  trim reference speed and let goes of the column, the boeing 777 will apply elevator accordingly to achieve the trim reference speed set (this is all in manual flight mode with autothrottle engaged).  But if the pilot inputs their own control the system is canceled out and it will only engage again when the control yoke is in the neutral position.

 

Is the above 100% correct?

 

 

Alex

[scandinavian13 5,192]

 

 

Is the above 100% correct?

 

No.  Think of it like a Cessna.  If you're out of trim, you're out of trim.  This is related to speed - nothing else (excepting the Boeing additions for gear/flap conditions).

 

If you push the plane out of trim, you're going to get a heaviness in the controls (in the opposite direction of the trimming).  If you let go, the plane will climb/descend to achieve the trim reference speed.  A Cessna would do this, too.  If you try to input your own control forces, you are doing so at the resistance of the current trim ref speed versus the actual speed.  If you are still grossly off of the ref speed, you will meet resistance on the yoke.  If you're close to the trim ref speed, you will be met with nearly neutral forces.

 

The plane isn't going to vanquish forces on the yoke just because you're touching it.  In fact, Boeing added forces back into the yoke to ensure pilots could feel it behaving just like the planes they started in.

 

As I've stated time and time again in these threads, people are really over-thinking this.

 

 

 

Trim is trim is trim - at least when it comes to conventional aircraft - of which the 777 is one.  Trimming in a Cessna/Piper/Diamond/Beech/etc is the same as trimming here.  The difference is that the 777 automatically adjusts for flap and gear changes, and a few other minor things (turn backpressure, etc).

[aceridgey 330]

No.  Think of it like a Cessna.  If you're out of trim, you're out of trim.  This is related to speed - nothing else (excepting the Boeing additions for gear/flap conditions).

 

If you push the plane out of trim, you're going to get a heaviness in the controls (in the opposite direction of the trimming).  If you let go, the plane will climb/descend to achieve the trim reference speed.  A Cessna would do this, too.  If you try to input your own control forces, you are doing so at the resistance of the current trim ref speed versus the actual speed.  If you are still grossly off of the ref speed, you will meet resistance on the yoke.  If you're close to the trim ref speed, you will be met with nearly neutral forces.

 

The plane isn't going to vanquish forces on the yoke just because you're touching it.  In fact, Boeing added forces back into the yoke to ensure pilots could feel it behaving just like the planes they started in.

 

As I've stated time and time again in these threads, people are really over-thinking this.

 

 

 

Trim is trim is trim - at least when it comes to conventional aircraft - of which the 777 is one.  Trimming in a Cessna/Piper/Diamond/Beech/etc is the same as trimming here.  The difference is that the 777 automatically adjusts for flap and gear changes, and a few other minor things (turn backpressure, etc).

 

The current version of the 777 does not behave like a cessna, it behaves like I described. 

[martin-w 3,234]

I approach it from a more humanistic level.  I wouldn't go into any developer's forum and start accusing them of wrongdoing unless I could prove it as fact.  Further, I wouldn't say a word about an issue until I've raised it to them first (not sure if he has or not - just a point to be made).

 

Ready for new code, as you see fit, though... 

Neither would I, but that's not the point, what you would do is irrelevant.

 

What is relevant is that if we are always a milimicron away from admonishing forum members then forum Armageddon is assured.

 

Tolerance on the other hand and refraining from being so quick to chastise is great news for the forum.

 

As for "new code" that won't be happening. I have already moved on to my latest creation, namely Kylie 1.00. Yes, a girl droid, somehow that excites me more.

 

I will save your groinal socket in case I need a spare for my Dyson.

[scandinavian13 5,192]

The current version of the 777 does not behave like a cessna, it behaves like I described. 

 

I'm confused.  You said that was information you had gleaned from a real pilot.  So which is it?

[777simmer 117]

But if the pilot inputs their own control the system is canceled out and it will only engage again when the control yoke is in the neutral position.

 

Ok I'll byte.....I really did not want to get involved into this endless trimming debate as I am having great fun with a now nicely flyable PMDG777 on a system that has never performed better!!

 

 

No real world 777 pilot, can tell you when "the system" (whatever you mean by that) of the real 777 is cancelled out, engages, disengages or who knows what else it does and simulates!

 

You would have to be a tech to know what "the system" does and when it does what.

 

You dont need to be a tech to fly the real 777 though.

 

All you need to know is that when you feel a force on the yoke......you have to trim it away.

That is pretty much all we are told and tought by Boeing (aside from thos augmentations for config changes etc).

For all practical purposes; Who cares how the system works behind the screen!

No need for thinking.....just do it.....no matter if you are pushing or pulling.....trim it away!

 

With something this simple why would one even think about whether or not the yoke is neutral....and whether or not "the system" has engaged or cancelled out something or whatever......you would not and no real world 777 pilot does.

 

 

Kyle is right.

And I have been saying this also from shortly after the PMDG777 came out and some guys were doubting the FBW system.........:

The real 777 feels like any other conventional aircraft...period!!

 

Cessna, B737, B777:

- in trim: the nose stays where you have pointed it too even without holding the controls (ofcourse the yoke is in neutral then)

That IS the whole purpose of trim to begin with......so you dont have to sit there for hours holding the nose where ever you need it (climb/cruise/descend.....same same....you dont want to have to hold it)

 

- not in trim: the nose does not stay where you have pointed it to (up/down/level....does not matter).

In this situation you have to push or pull to keep the nose in the required position. the more out of trim you are the more you have to push or pull and thus the heavier it gets (same for all conventional aircraft and the 777).

 

 

The reason the debate about 777 trimming came up and became such an issue is because PMDG had it wrong and took too long to realize it. In the meantime the debate had flamed beyond anything else here.

And because of that, now we cant stop discussing and doubting the system as it is today.

 

I have gotten a bit tired about the whole trim issue to be honest (I assume PMDG even more so) and I have accepted that trimming is as good as PMDG can get it.

I have mentioned somewhere in this thread that the PMDG777 trimming is now impressively close to the real thing.

Maybe that was a little exaggeration.....what I should have said is that it is much better than before and that IF....IF I have the FBW trim ref speed displayed THEN I can trim it perfectly and THEN the aircraft reacts like the real thing.

 

the real thing I can trim by feel....the PMDG I can trim perfectly...but only with the FBW trim ref speed displayed.

 

The reason for that is that there are still situations my trim inputs do not become active untill I have released my yoke.....and then the nose starts going somewhere (up/down) I did not intend it to go because it is now over trimmed in the other direction.

 

Now I am not a programmer and I am learning something new about FSX every day.

(I recently learned that my CDTs on exit were caused by my hardware......I had no idea this was even possible).

So I do not know whether or not my "trim by feel" problems are because by my hardware or another fault on my part (a setting somewhere).

I am willing to accept that idea though, because it seems others are not having any problems at all and CAN trim by feel under all conditions of flight.

 

Someone suggested the idea of introducing a dead band zone on the pitch axis. I have no dead band zone on my pitch axis right now (or one that is so small that I am not aware of it) as my yoke seems to perfectly return to neutral when I let go (spring loaded).

This is something I will have to try next week or so.

And I also have to experiment more with the FMC dead band setting......something that seems to have no effect at all here....or I am too blind to see it.

 

I also do not know if the yokes driver dead band and the FMC dead band have any effect on one another??

 

 

I really don't think there is anything more I can say about this trim issue.

[aceridgey 330]

Ok then do an experiment in the 777.

 

Fly  neutral and put the trim speeds up  (apply slight pressure in the oppposite direction ) and while watching the flight controls ECAS page, watch what it does when you release the column.

 

Report back

 

*I get a moderate deflection of the elevators *

[johndrago 4]

 

 

the real thing I can trim by feel....the PMDG I can trim perfectly...but only with the FBW trim ref speed displayed.

The reason for that is that there are still situations my trim inputs do not become active untill I have released my yoke.....and then the nose starts going somewhere (up/down) I did not intend it to go because it is now over trimmed in the other direction.

 

Hi Rob,

 

Based on what you've written, can you suggest the best way to utilize the trim ref speed display to keep the plane in trim without ending up with the over trimmed situation you mention that I seem to keep running into on climb.  I keep expecting the trim to work as smooth as the 737, however I understand this plane is different.  What I'm looking for is a quick tutorial on how to use the trim ref speed  to make it smooth. 

 

Thanks,

 

John

[777simmer 117]

Hi Rob,

 

Based on what you've written, can you suggest the best way to utilize the trim ref speed display to keep the plane in trim without ending up with the over trimmed situation you mention that I seem to keep running into on climb. I keep expecting the trim to work as smooth as the 737, however I understand this plane is different. What I'm looking for is a quick tutorial on how to use the trim ref speed to make it smooth.

 

Thanks,

 

John

No 737 and 777 are no different......PMDG737 and PMDG777 yes they behave different on my PC. But they should not.

 

Again it could be my hardware or whatever.

 

 

I suggest you display the trim Ref speed at all times.

 

I am asuming AT is engaged!

This is important because eventually the AT will try to get and keep you at this speed....so eventually you want the FBW trim ref speed right in the middle of that speed bug.

 

(handflying with manual throttle is different because it does not matter where your bug is.....you need to trim for what speed you are actually holding.

If you are a good pilot; actual speed=target speed bug......but since you are alone in there and busy, at times your actaul speed and the target will not be the same and you have to retrim so the FBW trim ref speed is/stays at your ACTUAL speed.....not the speed bug)

 

 

During acceleration from an in trim situation:

keep the FBW ref speed 10-15kt above the actualy speed as the aircraft accelerates.

This way you can pretty much not touch the yoke and fly (keep the pitch you desire) by just repeatedly touching the trim switches. Fly by trimming basically and only here and there help a a bit with they yoke if the nose wants to drop a little.

(Not keeping a continous yoke input helps those trim inputs actaully going to the FBW system as on MY system they dont go there if I holde the yoke)

Not more than 15kt above actual speed as that would cause too much of a nose down tendency.

Not less than 10 kt to prevent blib trim from your inputs going in an unwanted direction (to the actaul speed).

 

Don't sit there and count the knots though....just kinda use the force to estimate that roughly :-)

 

As the actual speed increases you have to keep nodding the trim switch to keep the FBW trim ref speed above the current speed.

When you reach the center of your magenta speed bug you stop trimming.

Since the AT will keep the speed....you are now in trim

 

During clean up after take of you do the same.

Keep the FBW trim ref speed 10-15kt above actual speed.

Again flying with trim basically.

This results in a shallow climb (at 280.000KG take of mass I get for example about +1500fpm this way and a nice acceleration).

 

During deceleration from an in trim situation:

Do the opposite.

Keep the FBW Trim ref speed about 10-15kt below you actual speed while you get slower.

Stop trimming when you reach the center of the speed bug and wait for the AT to catch up.

You are now in trim.

 

 

EDIT: oh....and once you are in trim.....do not touch them trim switches again untill you are again changing speed. So to change pitch to a climb or descend or level off......all you do is point the nose where you want it......steady it......and it will stay there without you having to touch the trim switches at all!!

[johndrago 4]

 

 

No 737 and 777 are no different......PMDG737 and PMDG777 yes they behave different on my PC. But they should not.

 

This is what I've been seeing as well.  They behave very different.

 

With that said, thanks for taking the time to give us a guide to follow.  This will help me a lot to gain control of the trim.

 

Thanks,

 

John