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+1 vote
asked by (17 points)
Hi Piloits/programmers,

I 've noticed that the C172SP that came with X-Plane  has  trim  issues,. and you can see it as well plus I as realworld student pilot can say with certainty that the elevator shouldn't move while trim off for airspeeds. and attidudes.

Just walk around the C172 look at the elevator and trim/antiservo tab (in X-Plane) now move your trimwheel back and forth, you'll see the elevator as well as the trim/antiservo tab is traveling counter wise each other.(error), just the servo should traveling up/down.

Now just move the yoke back and forth (for pitch), you'll see the trim/antiservo tab isn't traveling, thats (ok). The trimwheel   is   just  for   the   trim/antiservo tab,   and   the   elevevator  shouldn't   travel  with it..

So in flight while climbing for a long distance you would prefere to ease of some what back elevator pressure thus moving  just the trim/antiservo tab  (by trimwheel)   for a climb attitude untill you'll reach the desired 'altitude' as well as for attitude for e.g slow flight holding attitude untill you'll reach the disired 'attitude' needed, and here comes the eratic trimming (jumping up/down from the nose in X-Plane at the moment) both the elevator is traveling as well as the trim/antiservo tab  where X-plane thinks it is pitching up/down and simultaneously trimming.  (as seen) And   that's   a   big   error!

The trimwheel is just for the antiservo, not for elevator inputs.. That's why I never got a good trim for airspeed as well as a climb/decent attitude. When trimmed correct and simultaneously releasing the yoke is a hell to keep it good.

You guys need to disconnect elevator inputs that is linked with the trimwheel inside the C172  or we can just better fly the C172 just by using the trimwheel for pitch instead of yoke, yeah for banking haha ok but, that isn't good flying practice.

Hope you guys take care for it soon, it'll make X-Plane feel right forever!
commented by (12 points)
Have the same issue.
commented by (36 points)
On X-Plane 11 Beta 11, I have been flying on instruments a lot the past week or two (practicing for the real checkride), and I've found the trim of the C172SP to also be very unrealistic.  I find it WAY harder to trim out the plane for straight an level flight, holding specific airpspeeds, etc., as compared to a real C172.  I haven't dug into the details of what the sim is doing with the trim wheel inputs (as described above) but I can tell you it is very very hard to trim to an airspeed or altitude, no matter the calibration settings used (using Saitek Cessna Proflight yoke/pedals/trim/throttle).
commented by (17 points)
Yes indeed e.g walk to the antiservo tab on the empenage, position your eye at elevator level and adjust your trimwheel, you'll notice the elevator as well as the antiservo tab are moving wich X-plane thinks you are using your elevator (yoke movements) all together so, holding pitch for speed/attidude and using trimwheel separately  to release elevator pressure (yoke pressure) ends always up withe extra handling the yoke back and forth....instead releasing the yoke pressure after trimming.

 

So conclusion is we can't trim by trimwheel alone but with yoke simulataneously.

1 Answer

0 votes
answered by (16 points)
I have experienced a similar issue in x-plane 10. I would describe it as runaway trim. Using the Saitek trim wheel, and the basic C172, a slight movement of the trim wheel (trim up, I think) caused the pitch to increase drastically and it took full forward elevator to reverse this. I am a "real world" instrument rated pilot and I can agree with QNH that the trim is much easier to use (more predictable) in the "real airplane". Any tips to make the behavior of Saitek's trim wheel more realistic would be appreciated.

Thanks.
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