Realtrim Professional

[mryan75]

This is not specific to the Cherokee, although that is what I fly. This is for those of you who fly GA aircraft and find trimming an absolute pain, like I did. (And before my novel, if you've read that this doesn't work with A2A aircraft, it does work for my Cherokee)

Back in the FSX days there was a tiny little program, Realtrim. It was free. You set the pitch attitude (actually the airspeed) you wanted, pressed a button, released pressure on the yoke, released the button, and violard - the aircraft was in trim. To me it was one of the best addons in history. The original designer updated it for XP11, but he said the coding was too laborious for P3D.

If you fly GA aircraft in P3D, you know what a pain trimming is (unless you have the Saitek panel with trim I suppose, or the Cessna trim wheel). Otherwise it's an exercise in futility. I came up with what I thought was a pretty bright solution: since I don't use a controllable pitch prop, I don't need the blue lever on my Saitek throttle quadrant. So I set that as my trim. Which works okay, but it's still not ideal.

Just yesterday I was using the google machine and I checked again on Realtrim for P3D. I found Realtrim professional on one of the payware sites. I did some reading on various forums, and found that some people who had tried it with A2A aircraft in P3D said it didn't work. There's even a video on YouTube of an A2A Comanche going inverted using Realtrim Pro. But given its price, I decided to give it a try. It works slightly different than the original in that you click whichever button you set and release it, then release pressure on your yoke and the trim is then set, but essentially it's the same thing and is just as delightful. No fussing with the trim, no clicking the electric trim 800 times on an ILS approach, just click, set, and forget.

I know this was a huge issue for me, and I'm guessing for others, so I wanted to take the time and let everyone know. If trimming is a pain for you, get Realtrim Pro. And I have no association with it at all. It's just a wonderful product.

[KarelPatch]

Wow this looks awesome! I can’t believe how much this is going to change my life! Sim trimming is really impossible in most cases. Thank you so much for the tip

[AKar]

Not to take anything away if one finds such addons useful, but generally speaking if one finds trimming in the simulator overly difficult I find it probable that one is doing something wrong.

-Esa

[Oracle427]

I share Esa's sentiment. Again, not frowning upon the use the add on.

The process of trimming shouldn't be too difficult in the sim. All you need to do is use the yoke to hold the attitude and simultaneously trim while keeping the attitude fixed with the primary controls.

Eventually you will find the yoke has reached center of travel (no more force being applied), and you can let go. Same procedure as on the real world, though the physical movement of the yoke is not correct.

Don't focus on the control, focus on maintaining the attitude.

[Hook]

Same procedure as on the real world, though the physical movement of the yoke is not correct.

When trimming using this technique I never notice the movement of the yoke. I just adjust the trim until I'm not putting pressure on the yoke. While the yoke moves, it does have a centering spring and I go by the feel of this. I do not have a centering detent in my yoke.

A2A has discovered that there are yoke position flyers and yoke pressure flyers, and Accu-Feel has an adjustment for this as documented in the Accu-Feel forum and probably the manual. I wonder if the difference is that the position flyers have a centering detent.

Hook

[AKar]

Actually, what makes trimming difficult to me in some simulators/airplane addons is too fast trim behavior. In those, slightest thumb click of the trim switch is enough to cause fairly pronounced response in pitch behavior, making the trimming an effort of clicking and seeing if the response is good. I find A2A products to be better than many in this; the trim takes proper amount of time to 'run' and I can almost subconsciously relax the stick.

I suspect the hyper-responsive trim behavior in some sim products is 'calibrated' for ones who fly by having the pitch control neutral and clicking the trim to fly the nose. I actually think about patenting a new kind of joystick and accompanying yoke product. They have no pitch axis at all, only roll. There will be a microswitch that activates when the stick or yoke is pulled with enough pressure. This is to be mapped to the elevator up key binding, and to be used to lift the nose up when taking off or to flare for landing. Other than that, trim alone is to be used for pitch. Perfect for casual FSX/P3D flying!

-Esa

[Oracle427]

Same procedure as on the real world, though the physical movement of the yoke is not correct.

When trimming using this technique I never notice the movement of the yoke. I just adjust the trim until I'm not putting pressure on the yoke. While the yoke moves, it does have a centering spring and I go by the feel of this. I do not have a centering detent in my yoke.

A2A has discovered that there are yoke position flyers and yoke pressure flyers, and Accu-Feel has an adjustment for this as documented in the Accu-Feel forum and probably the manual. I wonder if the difference is that the position flyers have a centering detent.

Hook

That is because you are doing it correctly. You shouldn't be paying attention to where the yoke is and simply feel that you aren't applying pressure anymore.

[Hook]

Actually, what makes trimming difficult to me in some simulators/airplane addons is too fast trim behavior. In those, slightest thumb click of the trim switch is enough to cause fairly pronounced response in pitch behavior, making the trimming an effort of clicking and seeing if the response is good. I find A2A products to be better than many in this; the trim takes proper amount of time to 'run' and I can almost subconsciously relax the stick.

A2A works because they've properly calibrated the trim.

Almost every other aircraft I have has had a tweak to the aircraft.cfg file for the elevator and/or rudder trim. Look for these lines:

elevator_trim_effectiveness = 1.0
rudder_trim_effectiveness = 1.0

Change the 1.0 to something smaller. This example is from the Manfred Jahn C-47. Both were previously 1.0.

elevator_trim_effectiveness = 0.333
rudder_trim_effectiveness = 0.2

Be aware that this changes the trim control animation a bit and may limit the amount of trim you can set. But you can more easily set the trim and even fine tune it if you wish. I have my joystick buttons for trim set for fast repeat. Right now, the Cherokee is a little slow to trim for my tastes, but I ain't gonna change it.

Hook

[AKar]

To be honest, I would state that the trim system in FSX/P3D is inherently flawed in the first place, and provides no true distinction between trimmable tailplane and elevator trim tab. Aerodynamic results of trimming in FSX/P3D are closer approximation of a trimmable horizontal stabilizer than that of a trim tab we'd expect in most small airplanes. This results in hilarious behavior when pushed a bit outside the expectations. Examples include the ability to grossly exceed the pitch authority of what would be possible using full elevator simply by deflecting trim tabs, and possibility to counter the primary surface deflection by trim input. To some extent, some developers utilizing standard flight dynamics for this part have compensated for this, but it is like fitting a curve into a set of linear data points: it won't work except for some specific chosen circumstances out of numerous possibilities, and it may further distort the behavior elsewhere.

In what comes to trim speed specifically, I personally like the "slow" trimming in A2A airplanes. It provides me a smooth release of control forces. In airplanes with direct mechanical means of trim control alone, such as Cherokee, "calibrating" it is somewhat arbitrary. In others that utilize electrical trim control, matching the trim speed to that would make sense to me. What may be surprising is how long it actually takes to drive an electric trim from end to end in real airplane.

-Esa

[KarelPatch]

I share Esa's sentiment. Again, not frowning upon the use the add on.

The process of trimming shouldn't be too difficult in the sim. All you need to do is use the yoke to hold the attitude and simultaneously trim while keeping the attitude fixed with the primary controls.

Eventually you will find the yoke has reached center of travel (no more force being applied), and you can let go. Same procedure as on the real world, though the physical movement of the yoke is not correct.

Don't focus on the control, focus on maintaining the attitude.

I totally understand this principle and that’s what I try to do each time. But I find that the lack of feedback makes it very difficult to me. Maybe it’s an issue with my controller or just my coordination, but the slightest change in trim will have huge effect.

[Lewis - A2A]

its not a primary flight control so there is either a control issue or you are moving the trim too much if its flying all over the place. I would suspect the first one though of a simple techinical issue with the controls.

thanks,
Lewis - A2A

[Caldemeyn]

I have no problem trimming, be gentle man, hold your yoke and trim until you don't have to anymore, only then you may make tiny adjustments with trim by itself, or you may add or lower your throttle a tiny bit

[thunderstreak]

Remember also that trimming is not a one time thing. It is constant throughout the flight. With every power or speed change there will be a trim change necessary. If you fly an aircraft that burns fuel from one side independently of the other, as opposed to equally from both sides there will be regular trim changes required. As in real life one should be making minor adjustments through all phases of flight.