[wdrecker]

I would like to refer to the elevator trim topic, serverniae posted 24. June 2021 at 20:05.

I tested following two elevator trim options available in CLS2Sim with MSFS (referring to online help \ CLS profile manager \ Buttons):
Option 1: Select Not bound / USB Button in CLS2Sim and set trim up in the simulator.
Option 2: Use the Trim – Elevator up (or down) in CLS2Sim; this uses software to adjust the trim.
Accordingly, I configured the elevator trim settings in MSFS for option 1 or disabled them in MSFS for option 2 and did different tests over the entire trim range to check realistic position-, force and attitude-behavior. For trim option 1 and 2 the result was the same:

On-Ground-Tests:
Adjust trim range from full nose down to full nose up:
a) Force Feedback Stick released: Neutral position follows trim position; correspondingly, the elevator position in MSFS follows the trim position.
b) Force Feedback Stick held in neutral position: Hand forces increase or decrease according to the current trim position; accordingly, the elevator position in MSFS does not follow trim position.

=> In both cases, this simulation behavior meets the expectation and corresponds to real behavior of aircraft with elevator trim systems pre-tensioned by springs. It is different for aircraft using Flettner trim flaps or variable horizontal stabilizers as elevator trim system.

In-Flight-Tests:
Adjust trim range from full nose down to full nose up:
a) Force Feedback Stick held in neutral position: Hand forces increase or decrease according to the current trim position; accordingly, the elevator position in MSFS does not follow trim position.
BUT: The aircraft experiences significant attitude changes according to trim position, although elevator remains in neutral position.

=> This simulation behavior absolutely does NOT correspond to the expected flight behavior in reality!
Finally this reflects the expected behavior of MSFS, which was made for the impressions with a non-force feedback stick, in order to reproduce attitude changes with such a stick, without being able to change the neutral position of the stick.

Conclusion:
Both basic trim options behave identically, which is due to the behavior of MSFS, which does not know force feedback sticks and must readjust attitude changes during trimming regardless of the stick position!
This effect is hardly noticeable with small trim changes, as they are usually used in practice. At the limits, however, the behavior is no longer realistic and can lead to a total loss of control, since the elevator deflections to compensate for extreme load changes at maximum trim deflections may no longer be sufficient to control the aircraft. This does not correspond to reality at all!

Remark:
The third elevator trim option described in the CLS2Sim online help \ CLS profile manager \ Buttons was not tested as it was not available in CLS2Sim for unknown reason:
Option 3: Use Trim HW – Elevator up (or down) in CLS2Sim; this uses hardware functionality in the yoke controller to adjust the trim.
Probably this option could solve the problem identified and provide more realistic simulation behavior – even is this will leave the simulator “blind” to the stick trim setting. Unfortunately, I did not get any response from Brunner Helpdesk yet why this option is missing.

Does anyone have other elevator trim experiences with MSFS?

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