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aceridgey

Still Trim issues with Sp1b

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Hi guys,

 

For those who were getting the trim only activating when the joystick was dead centre, what are the results with sp1b?

 

I am still getting exactly the same issue.

 

 

Situation: I put on the trim ref speed bug

 

Fly constant speed and Altitude (Autothrottle on holding 240 for example).

 

 

Trim all the way down to say 180, (expecting a nose up attitude) and the aircraft pitches up.. As soon as I apply any elevator, the effect dissappears.

 

Same going up and down

 

 

Alex

 

==

 

Edit, I am feeling like the trim hasn't been modified at all, am I on the correct version here?

 

2ah8ns1.jpg


p.s I did not get any promt running the Operations centre (to back up liveries or anything)

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Alex, I forgot to refresh my browser and installed SP1 but not B. Did the file you downloaded have the number 6036 or 6061. If it says 6036, you installed the SP1, but not B

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Alex, I forgot to refresh my browser and installed SP1 but not B. Did the file you downloaded have the number 6036 or 6061. If it says 6036, you installed the SP1, but not B

 

I downloaded it just an hour ago, so I can confirm that it is the correct version, 6061 and the exe is titled sp1b

 

Alex

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I just retarted the PC and ran the EXE two more times.

 

Only on the second attempt, did the warning come up that I am wanting to install a previous version.

 

Then in the ops centre I got the notification and then FSX wanted me to confirm some new gauges.

 

Hopefully this will fix, trying now. 


Here is the 'correct' version showing..

 

30k3jb4.jpg

 

 

Trim issues still present.

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With trim ref that far below actual airspeed you should be needing to keep almost full forward deflection on the joystick to maintain level flight. I just tested this the other day with the version that went out yesterday and it worked as expected.

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I myself are finding the trim issues much improved. Like shown on many youtube video's you should use small inputs , wait for change then adjust. It's not a fighter jet :)

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With trim ref that far below actual airspeed you should be needing to keep almost full forward deflection on the joystick to maintain level flight. I just tested this the other day with the version that went out yesterday and it worked as expected.

 

Not working for me, I can just touch the joystick forward a little and it flies like an 'in trim state'

 

Alex

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Here too, Alex, are your controls set through FSUIPC and all control mappings deleted in FSX?

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I am just running through FSX.

 

It's when I completely neutralize the yoke, the aircraft will suddenly (delay of about 1 second) bubble up or down if the trim reference speed is forced out.

 

Alex

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Ok, I have nothing mapped through FSX, cleaned out all of it. Could never get rid of spikes and other troubles with FSX mappings, and the throttle problems when TO/GA was only solved when I followed a guide here, a long time ago.

 

I can't tell you that it will better your issues but at least I have never had the problems you mention. Could it be an idea to map only the elevator through FSUIPC and make a quick test?

 

Cheers,

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Not working for me, I can just touch the joystick forward a little and it flies like an 'in trim state'

 

Same thing i just experienced, the FBW trim ref speed was around 180kts while the actual airspeed was 240 and the plane felt in trim, its only when i just barely touched the joystick back slightly to dead center that the plane started to pitch up. Are you using a HOTAS warthog by any chance?

 

 

EDIT: Just set a small null zone in FSX advanced control axis for the elevator, it appears to have made it a little better, currently in climb now, will have to wait until my next flight later today after takeoff to see if this worked.

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Ok, I have nothing mapped through FSX, cleaned out all of it. Could never get rid of spikes and other troubles with FSX mappings, and the throttle problems when TO/GA was only solved when I followed a guide here, a long time ago.

 

I can't tell you that it will better your issues but at least I have never had the problems you mention. Could it be an idea to map only the elevator through FSUIPC and make a quick test?

 

Cheers,

 

 

Hi mate, thanks for your reply,

It's got nothing to do with if it's FSX or FSUIPC handling controls, I am pretty sure, as the flight controls (movement of yoke etc.) mirrors my input on the hardware.

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I see that, but how can our two systems react so differently? The only thing that seems different is how the controls signals are input to FSX?

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I see that, but how can our two systems react so differently? The only thing that seems different is how the controls signals are input to FSX?

 

Would be interesting to see others comment on it,

 

Alex

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Interesting comment regarding null zone above though, could it be that simple?

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I definitely had the trim issue prior to SP1b and I can report that it is much better with the latest update. Prior to the patch, I was all over the place, particularly in turns. Although I do have to apply yoke back pressure in turns, otherwise, trimming seems to work much better. I have my main flight controls (rudder, elevator, aileron) mapped in FSX. The only flight controls I have mapped in FSUIPC are the trim switch, throttle, and reversers. I have a 10% "null zone" set in the PMDG menu.

 

Regarding the back pressure in turns...I thought the 777 FBW was supposed to apply the elevator correction automatically in turns. I didn't think pilot elevator input was required in turns to maintain level flight. Am I incorrect?? Because if the FBW is supposed to handle the elevators in turns, that piece definitely isn't working.

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Trim is very good indeed for me now. Approach and landing was far superior as well.
 


Regarding the back pressure in turns...I thought the 777 FBW was supposed to apply the elevator correction automatically in turns. I didn't think pilot elevator input was required in turns to maintain level flight. Am I incorrect?? Because if the FBW is supposed to handle the elevators in turns, that piece definitely isn't working.

 



No that's not correct. The FBW only alleviates "some" of the back pressure required. The T7 still drops it's nose in turns to a degree.

 

You still have to apply a little back pressure in turns in the T7.

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Regarding the back pressure in turns...I thought the 777 FBW was supposed to apply the elevator correction automatically in turns. I didn't think pilot elevator input was required in turns to maintain level flight. Am I incorrect?? Because if the FBW is supposed to handle the elevators in turns, that piece definitely isn't working.

 

Incorrect.  The pilot must add back pressure.  This isn't an Airbus...

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The PFC’s compensate for turns up to 30 degrees of bank. There should be no need to apply extra yoke back pressure until the bank is greater than that.

Brian

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Interesting comment regarding null zone above though, could it be that simple?

It worked for me, it handles lovely now, and now I'm really seeing how the fbw is meant to behave.

 

My hotas warthog has a very tiny spike issue where it fluctuate rapidly between 200 and 280 parameter in the pitch axis forward of center, and it disappears when the stick is dead center and reads 0. Setting the null zone in fsx solves it for me.

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The PFC’s compensate for turns up to 30 degrees of bank. There should be no need to apply extra yoke back pressure until the bank is greater than that.

Brian

Correct. But in the real aircraft as well.....you have to kind of guide it along at first. So you turn.......make sure the nose stays where you want it and if not then you help it a little....and then once established in the turn you can pretty much let go.

Only tiny little adjustments are required every now and then to correct for the fact that changing winds etc are still trying to throw you of your path and since this is not an airbus, it will not correct for that.

 

The PMDG mimmicks this quite nicely with SP1b.

 

But....there are two buts.

1) it seems to take a little time for the PMDG777 to get back into its flight path stabilizing mode after an attitude change.

I do not know if my observation is correct but I find that when I make an attitude change that I kind of have to hold it there for a second before slowly letting go of the yoke.

If I let go of the yoke too fast then the nose seems to go back in the direction of its previous state. And because of that it sometimes needs a little more persuasion than I am used to.

I think that path stabiliing mode should kick in a bit quicker.

I assume that is what the FMC nullzone is for ? (I have it at 1%)....but please correct me if I am wrong.

 

2) Not having to hold the nose during a turn only works when you are perfectly in TRIM.

Even if there is only 5kt difference between the FBW trim ref speed and your actual speed the nose will go up or down. (As it should).

And here comes the thing.....even with AT on....one is often flying a few knots fater or slower than where the target speed bug is. This is normal too as the AT is not perfect. So when you turn while the AT is doing a not perfect job (lets say you are at 255kt but you have trimmed for 250kt and your speed bug is also at 250kt) then it will look like STAB turn compensation does not work. But it does....you are just out of trim and need to use the blib trim feature or wait untill the AT has corrected for the speed difference.

 

 

All in all I am getting much better results trimming by feel now.

I had big problems with varying over- and undersensitivity when out of trim. That seems to be gone now.

I would say 90% of the time I can do without feeling the need for displaying the FBW trim ref speed :-)

So definately quite good.

 

But I do also think that sometimes the trim inputs are not actually passed on to the flight model (or STAB) untill you let go of the yoke (neutral).

Again, I do not know if the cause for this is my yoke....the time delay it takes for the PMDG to go back to path stabilizing mode....or incorrect FMC nullzone settings (I have both at 1% now......but still experimenting).

For example, during a descending turn yesterday I thought I was in trim before I entered the turn (FBW trim speed not displayed). But in the turn I just could not keep the nose where I wanted it.....So I trimmed as I felt I had to.....but never got it stabilized. When I then displayed the FBW trim ref speed I saw I was still 15kt out of trim.

I would like to stress that this was not the case for all turns and maneuvers I tried!

Most of the times I trimmed by feel, and then checked where the FBW trim ref speed was, it was spot on :-)

 

I do not know why I could not get the trim right in that turn......but to not have to endlessly fight like that with pitch, I now just keep the FBW trim speed displayed......and with that, things work really well.

:-)

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For those who test, fly, but do not read the manuals:

 

Reference FCOM, page 9.20.10  from Dec 13, 2010

 

Normal Mode Pitch Control

The PFCs also provide compensation for flap and speedbrake configuration
changes, and turns up to 30° of bank. The PFCs automatically control pitch to
maintain a relatively constant flight path. This eliminates the need for the pilot to
make control column inputs to compensate for these factors. For turns up to 30°
of bank, the pilot does not need to add additional column back pressure to
maintain altitude
. For turns of more than 30° of bank, the pilot does need to add
column back pressure.

 

Apparently, not even the Betas are aware of this.

 

However, in straight and level flight, the SP1b is far better then the "triple U" previous version ( untrimmable, unflyiable, unreliable ) .

 

I am waiting the SP1c version already.

 

Vpira

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