Trim and stabilizers

[angus26]

This may sound like a silly question, but what is the difference between a "stabilizer" and trim in the game? I noticed that on aircraft such as the Ju 52 and bf 109 and others that it will say "stabilizer" but do not have trim, whereas other aircraft like the p-40 it will just say trim (in technochat). What is the difference in operation, and are there any noticeable differences in what they do? 

[AndyJWest]

In terms of function, there really isn't any difference, as far as WW2-era aircraft are concerned. Trim tabs adjust the neutral position of the elevator, whereas in aircraft using 'stabiliser' trim, the whole tailplane pivots. In both cases you adjust to give the desired 'hands off' position matching your desired speed and power settings.  An all-moving stabiliser has advantages when approaching transonic speeds, but that isn't really relevant to the BoX aircraft. You can bind the same controls to both types, and treat them exactly the same.

[Mitthrawnuruodo]

"Stabilizer" refers to mechanisms that change the angle of the tail plane. If you look at a Bf 109, you can see the whole thing rotate when you adjust the stabilizer.

 

In Il-2, "trimmer" refers to other solutions such as trim tabs. On a P-40, for example, you'll see the tabs moving when the trim is manipulated. 

 

They have the same function. Many modern airliners use stab trim to reduce drag.

Edited April 11, 2018 by Mitthrawnuruodo

[[CPT]Crunch]

A trim tab will directly relieve pressure on your elevator, a stab can't.  A stab can directly change pitch angle of the wing, not likely with a trim tab.  Some heavies use all three.

[AndyJWest]

27 minutes ago, [CPT]Crunch said:

A trim tab will directly relieve pressure on your elevator, a stab can't.  A stab can directly change pitch angle of the wing, not likely with a trim tab.  Some heavies use all three.

 

Nope. If you exert a force on the elevator which causes it to change its angle to the airflow, this will in turn result in change of force from the elevator and thus the angle of attack of the wing. If you change the angle of the stabiliser, this will likewise result in a change of force and thus a change in the angle of attack of the wing. Same thing.

[angus26]

10 hours ago, AndyJWest said:

In terms of function, there really isn't any difference, as far as WW2-era aircraft are concerned. Trim tabs adjust the neutral position of the elevator, whereas in aircraft using 'stabiliser' trim, the whole tailplane pivots. In both cases you adjust to give the desired 'hands off' position matching your desired speed and power settings.  An all-moving stabiliser has advantages when approaching transonic speeds, but that isn't really relevant to the BoX aircraft. You can bind the same controls to both types, and treat them exactly the same.

Correct me if I got this wrong, but the stabilizer has the same goal as trim, but a stabilizer instead of adjusting a trim tab, a stabilizer will move the control surface instead, effectively doing the same thing as trimming the aircraft.

[curiousGamblerr]

27 minutes ago, angus26 said:

Correct me if I got this wrong, but the stabilizer has the same goal as trim, but a stabilizer instead of adjusting a trim tab, a stabilizer will move the control surface instead, effectively doing the same thing as trimming the aircraft.

 

Not the control surface, but the entire stabilizer.

 

To clarify, the horizontal parts of your tail have two parts, the stationary stabilizer, and the movable elevator hanging off the back. Generally, "control surfaces" refers only to the elevator, not the entire horizontal.

 

So the one clarification to your statement is that yes, the stabilizer adjustment is effectively doing the same thing as trimming, but it moves the entire stabilizer, not just the control surface.

 

Trim, on the other hand, uses a small tab to deflect the just the control surface itself, not the entire stabilizer.

 

A picture's worth a thousand words:

 

http://aviation_dictionary.enacademic.com/pictures/aviation_dictionary/f0292-01.gif

[angus26]

26 minutes ago, 19//curiousGamblerr said:

 

Not the control surface, but the entire stabilizer.

 

To clarify, the horizontal parts of your tail have two parts, the stationary stabilizer, and the movable elevator hanging off the back. Generally, "control surfaces" refers only to the elevator, not the entire horizontal.

 

So the one clarification to your statement is that yes, the stabilizer adjustment is effectively doing the same thing as trimming, but it moves the entire stabilizer, not just the control surface.

 

Trim, on the other hand, uses a small tab to deflect the just the control surface itself, not the entire stabilizer.

 

A picture's worth a thousand words:

 

http://aviation_dictionary.enacademic.com/pictures/aviation_dictionary/f0292-01.gif

Ah, that makes much more sense. Thanks for the clarification. 

[[CPT]Crunch]

20 hours ago, AndyJWest said:

 

Nope. If you exert a force on the elevator which causes it to change its angle to the airflow, this will in turn result in change of force from the elevator and thus the angle of attack of the wing. If you change the angle of the stabiliser, this will likewise result in a change of force and thus a change in the angle of attack of the wing. Same thing.

That will be pilot and airspeed dependent, not necessarily so in a heavy on a slow speed approach.

[AndyJWest]

5 minutes ago, [CPT]Crunch said:

That will be pilot and airspeed dependent, not necessarily so in a heavy on a slow speed approach.

 

Aerodynamics is the same for a 'heavy on a slow speed approach' as it is for any other aircraft. The control forces might be greater, but they have servo mechanisms for that.