maximum angle of aileron and rudder? 1

[lisamaverick]

Dear everyone:

If anybody here by chance know that what the maximum angles for aileron and rudder for a practical aircraft?
I do not think that is -90deg and +90deg, is it right?


Thanks a lot.

lisa

 

[debodine]

On the Boeing 767-300 aircraft (I happened to have the aircraft maintenance manual handy) the total rudder deflection is about 26 degrees left and right, the total elevator deflection is about 28 degrees up and 20 degrees down, the total inboard aileron deflection is about 21 degrees up and down, and the total outboard aileron deflection is about 30 degrees up and 15 degrees down.

This just for one aircraft type, but at least in the commercial aircraft regime these values will be somewhat typical. Of course on an aircraft this size the spoilers work in conjunction with the ailerons so on aircraft without spoilers, the aileron deflection may be a bit more to obtain the required performance.

debodine

 

[rb1957]

is the question related to the loads on an aileron/rudder/elevator ?

 

[tmoritz]

Two issues with control surface deflection that are considered during design. One issue is the loads generated, can the surface take the load without deforming? Can the control system, cables, rods, crank arms, linkages, hinges, etc. take the load? Can the pilot supply sufficient control input force to deflect the control surface to the full extent?

The other issue is the aerodynamics of the control surface. Control surfaces can be considered airfoils that are closely cascaded with the surface to which they are attached. It is possible to deflect the control surface so far and increase the angle of attack to the point of stall or flow separation. At this point your control effectiveness will drop precipitously and drag increases. Take a look at the split rudder on the space shuttle.

 

[berkshire]

Lisa

If you got to

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

You can get the type data information of most makes and models of aircraft certificated in the US. Just enter the make and model of the aircraft you want to check on.
This information will include control allowable or required control deflections on a large number of the aircraft listed.
This may assist you with your inquiry.
B.E.

 

[Noor]

The +/-90 degrees surface angle is often used in the specification of instrumentation to measure control surface positions.

The measurements are used for flight control computers and flight data recorders.

Although the measurement resolution is reduced, a good instrumentation system covers a larger angle range than the actual max angles in order to account for abnormal surface deflections that may occur if a linkage is broken or the surface is overloaded.

 

[ActiveSolar05]

LQQK in "Theory of Wing Sections" by Abbott & Von Doenhoff.
Dover edition is a nice softback : ISBN 0-486-60586-8.

LQQK at page 488 & 489 this is the *classic* NACA 4412 wing shape. See the moment coefficient vs angle of attack ? you have to provide that down force (on a rear tailed aircraft) just to keep it flying straight & level BEFORE you add any forces for maneuvering. See page 462 / 463 for the 0012, a typical control surface shape.
try

http://www.soton.ac.uk/~jps7/D8 website/UIUC Airfoil Coordinates Database.htm

bye
jrr

 

[lisamaverick]

Hi Guys;

I have not come here for a long time.
Thank you all for the detailed information. That is really helpful for me.

Lisa