the question is simple:

 

will the horizontal stabilizer / elevator rotate with trim?

 

if the answer is: of course! - great!

 

regards,

peter

 

 

 

will the horizontal stabilizer / elevator rotate with trim?

 

No. The landing gear, ailerons, flaps, slats, elevator, and rudder are not going to be modeled (sp?).

 

But the MD-11, 737, 747, and J41 (I think) all have moving horizontal stabilizers. So my guess is yes.

I would suspect that on the ground, trim would cause only the trim tabs on the elevator to move.

 

When in flight, likewise adjusting trim should move only the trim tabs directly, but the change in aerodynamic forces on the tabs should cause a reactionary movement of the elevator.

 

Can anyone verify if "trim" changes are tied to trim-tab movement with elevator movement being a secondary response, or will it be a short-cut input fed directly to elevator repositioning?

That's simulated perfectly (system and graphic wise) in DCS, when you set aircraft on ground and trim, only trim tab will move, but if you sit on ground with high headwind and try to trim, whole aileron/rudder will move. For elevator, I thing it should fall under gravity effect, so you need lot of headwind to hold it in position (of course, if you do not touch a stick)

I would suspect that on the ground, trim would cause only the trim tabs on the elevator to move.

 

When in flight, likewise adjusting trim should move only the trim tabs directly, but the change in aerodynamic forces on the tabs should cause a reactionary movement of the elevator.

 

Can anyone verify if "trim" changes are tied to trim-tab movement with elevator movement being a secondary response, or will it be a short-cut input fed directly to elevator repositioning?

If you are talking about the J41 then yes, pitch trim moves an elevator trim tab.  That creates a hinge moment offset which changes the neutral position of the elevator in flight.  In the normal control range moving the trim tab has no mechanical effect on the elevator but there might be an effect on the control end stop position, so at extreme surface angles the trim tab might possibly move the elevator.

 

 

J41 (I think) all have moving horizontal stabilizers

The J41 has a fixed horizontal stabiliser.

The elevator itself is moved by the hydraulic system, this is not an MD-80. I would think that the horizontal stabilizer will move with change of trim.

Yeah of course it will do! Why shouldn't it? The MD-11 does it and I guess the NGX does it too.

The reason I ask is because on the 747-400 for FSX, they chose not to model it.

I would suspect that on the ground, trim would cause only the trim tabs on the elevator to move.

 

When in flight, likewise adjusting trim should move only the trim tabs directly, but the change in aerodynamic forces on the tabs should cause a reactionary movement of the elevator.

 

Can anyone verify if "trim" changes are tied to trim-tab movement with elevator movement being a secondary response, or will it be a short-cut input fed directly to elevator repositioning?

 

The horizontal stabilizer trim move the whole horizontal stabilizer(the rear smaller wing). The horizontal stabilizer doesn't have trim tabs, it has balance tabs to assist the elevator. The vertical stabilizer is the one that have trim tabs.

 

 

I would suspect that on the ground, trim would cause only the trim tabs on the elevator to move.

 

When in flight, likewise adjusting trim should move only the trim tabs directly, but the change in aerodynamic forces on the tabs should cause a reactionary movement of the elevator.

 

Can anyone verify if "trim" changes are tied to trim-tab movement with elevator movement being a secondary response, or will it be a short-cut input fed directly to elevator repositioning?

 

from FCOM for a better explanation.

 

The reason I ask is because on the 747-400 for FSX, they chose not to model it.

 

I'm not even sure that's true, but cmon - the 400X is an ancient product now (6+ years ago) compared to our current level of modelling. The 777 model absolutely does everything the real airplane does as far as surface motion etc.

exactly why I ask about it.

As far as the horizontal stabilizer goes, the MD80 is the same as the others. Moving pitch trim in the cockpit operates an electric motor that moves the whole stabilizer. The elevator has three tabs, the control tab that "flies" the elevator. A geared tab that assists the control tab and an antifloat tab that aids in forward MAC landing configs.

 

Xander

Think we officially ran out of questions  :rolleyes: