Airliner Flight Controls Options

[p3flighteng1]

About something we do not have on a P-3. When I fly Commercial, I have noticed some different flight control surfaces. In a turn, I see the ailerons move, but center wing I see another surface move with it in a turn. Left wing down, aileron up, mid surface control up. I only noticed it during descent and approach. Is this to assist the aileron or am I missing something? Thanks...............................FE

[c150student]

Arent they spoilerons?

They act like spoilers, detroying some lift on that wing, pushing it down more. So, especially when in a hard turn, the spoilerons will come up on the into-turn wing to make it drop quicker. When the controls are centered as bank angle is reached, the ailerons and spoilerons should become centered again. I think theyre the same panels as spoilers, but on some aircraft it may be that only some of the spoiler panels act as spoilerons.

Ranger or Airrabbit are sure to correct me and add much more information.

If I were to be in FS preaching mode, I'd say go on flight sim and have a look on something like the 737. Even when on the ground, move your joystick way out to the left/right and have a look at the control surfaces. Then hit the / key, which is the spoilers key. You should see the same central panels rise again.

Of course, if you can do this in a real plane, all the better!

[trijetflyermd11]

C150student was pretty much there already. The spoilers move up to roll the aircraft. The ailerons are usually locked in neutral position at higher speeds (i.e. after flaps up) to avoid wing twisting. The spoilers have an additional advantage. They cause drag on the inner side of the turn and thereby produce the required yaw for a coordinated turn. Some aircraft also have inboard and outboard ailerons. Here again at higher speeds (i.e. cruising) only the inboard ailerons move to assist.

[glnflwrs]

I've seen AirRabbit refer to these control surfaces as "roll control spoilers", and they function as c150student and trijet stated.

[AirRabbit]

Sheesh! You guys read and remember better than I do! I'd add something to the discussion, except for the fact that there really isn't anything to add. The subject was pretty well covered. Nice job guys!

[glnflwrs]

We have a good teacher.

[p3flighteng1]

C150student was pretty much there already. The spoilers move up to roll the aircraft. The ailerons are usually locked in neutral position at higher speeds (i.e. after flaps up) to avoid wing twisting. The spoilers have an additional advantage. They cause drag on the inner side of the turn and thereby produce the required yaw for a coordinated turn. Some aircraft also have inboard and outboard ailerons. Here again at higher speeds (i.e. cruising) only the inboard ailerons move to assist.

Thanks for the info. Never even thought of the cooridnated turn with a yaw advantage. cool FE