Pitch Trim runaway

[Bobben 0]

Hello!

Just wondering, is the pitch trim supposed to be operated in a special way on this aircraft?

For me it sometimes seems to live a life on it's own. With one click on the trimbutton on my saitek yoke, it often just moves "one click", as on most of my other aircrafts, but at other times, it just kind of "keeps going" and make a rather large adjustment. There is nothing in the manuals about this, but in the description of the aircraft at aerosoft, there is a (for me at last) little bit cryptic statement: "Realistic pitch trim simulation: You can actually trim the aircraft to fly the attitude you want, not the attitude FSX "thinks" you want...".

/Bjorn

[Bjorn Comhaire 27]

For me it sometimes seems to live a life on it's own. With one click on the trimbutton on my saitek yoke, it often just moves "one click", as on most of my other aircrafts, but at other times, it just kind of "keeps going" and make a rather large adjustment. There is nothing in the manuals about this, but in the description of the aircraft at aerosoft, there is a (for me at last) little bit cryptic statement: "Realistic pitch trim simulation: You can actually trim the aircraft to fly the attitude you want, not the attitude FSX "thinks" you want...".

Hi,

No the trim is not supposed to run away, in fact we have created a system to avoid large Trim changes! For this we use FSIUPC, so please make sure you have FSUIPC correctly installed, you need version 4.588 or higher. The current version is 4.60a.

Now what I think is going on is this: when you keep the mouse button pressed the mouse sends a number of "trip up" or "trim down" events to the simulation. The longer the button is pressed the faster the succession of these commands. FSX can't keep up with this and containues to send trim messages even though you don't press the button anymore. So this will probably happen if you keep the button pressed for a long time.

At this time you can do two things to avoid this:

- in FSX open the "Settings->Controls->Buttons/keys" and change the slider of the elevator trim up and down events to the middle position

- use shorter trim bursts when setting the trim, instead of keeping the button down for 5 seconds use 2seconds, release the button shortly and press 2 seconds again.

In SP2 this issue should be resolved as we have removed FSUIPC from the equation altogether.

Kind regards,

BjÖrn

[Bobben 0]

I have FSUIPC 4.60 (registered) installed, and i manage all my buttons, switches and axis control trough FSUIPC. All controls are disabled in FSX itself. I'm aware of the possible "lag" when holding the trim button down in repeating mode, but that is not the issue here. Even if a disable the "repeting mode" for that button(s) in FSUIPC, ie it only registers just "one click" per press , it still "runs away". No other of my aircrafts shows this behaviur.

/Bjorn

[Bjorn Comhaire 27]

I have FSUIPC 4.60 (registered) installed, and i manage all my buttons, switches and axis control trough FSUIPC. All controls are disabled in FSX itself. I'm aware of the possible "lag" when holding the trim button down in repeating mode, but that is not the issue here. Even if a disable the "repeting mode" for that button(s) in FSUIPC, ie it only registers just "one click" per press , it still "runs away". No other of my aircrafts shows this behaviur.

If you disabled trim altogether then what it most likely happening then is that I can't catch the trim event at all and thus my whole logic behind controlling the trim goes crazy as it is based on "normal" FSX behavior. Is it possible for you to have a separate FSUIPC setting that doesn't disable the FSX trim ?

Björn

[Bobben 0]

If you disabled trim altogether then what it most likely happening then is that I can't catch the trim event at all and thus my whole logic behind controlling the trim goes crazy as it is based on "normal" FSX behavior. Is it possible for you to have a separate FSUIPC setting that doesn't disable the FSX trim ?

Björn

I think you have missunderstood what i wrote. I have not disable trim all together at all, the trim event is still there for you to catch. The only difference is that i let FSUIPC manage all key and axis configuration, simply because it does a much better job doing that, then the built-in configurator in FSX itself. You can read all about it in your documentation of FSUIPC (placed in the fsx/modules folder). When i press my TrimUP and TrimDOWN buttons on my yoke, FSUIPC injects/sends the corresponing events: ELEV_TRIM_DN (65607) or ELEV_TRIM_UP (65615) in to FSX.

Could it be that your special trimfunction, with what ever calculations it makes, are somewhat slower to react/execute/finish to those messages, and therefore more easely get kind of "flooded"?

/Bjorn

[Bobben 0]

I have now tried setting the trim with the default (fsx) keys from the keyboard, num1 and num7, but the behaviur is the same. I tried with different intervalls between the keypresses, but even with quite long delays between each keypress, it acts the same. The behaviour seems almost random at times.

Its not a big issue, just a little annoying when you trying to do small adjustments on the approach. Perhaps it has something do to with FSUIPC, SP2 will tell.

/Bjorn

[Costas 0]

Hi,

I have the same problem as Bjorn. When I adjust the trim on ground or in flight, the trim wheel on the throttle block moves step by step with each klick on the 1 or 7 key. But then suddenly the trim wheel moves up from let us say 2 units to 2.9 units (or down) with the corresponding next click. The next clicks show normal behavior. And with further clicks it suddenly moves again.

Pushing the slider of the elevator trim in FSX to the middle position does not change anything.

I´m on Windows XP, FSX SP2, FSUIPC 4.60a

Martin

[Bjorn Comhaire 27]

Hi Martin,

The issue will be fixed in SP2, hope it doesn't cause to much problem during the flight.

Björn