On a full size/scale aircraft what are the mini nacelle looking things on the wing?

[billiam2536]

what are these things. I have searched every where I can for a name or explanation but have come up dry. Does any body out there know what they are? Sorry if this is in the wrong thread, I couldn't decide where to put it since I don't know the purpose of the the objects in question. Attached is a picture of what I am talking about, they are the 4 pod like things on the back of the wing. :confused: HELP ME! :confused:

[JetPlaneFlyer]

They are housings for the actuators that operate the flaps.

[billiam2536]

thanks! that has been bugging me for a while.

[Flyingwingbat1]

They also help smooth out the fore-to-aft cross-section distribution of the plane, i.e. they help with the "area rule" effect. Area rule states that the cross-section area of a transonic/supersonic aircraft should transition smoothly as you go from front to back; it should start out small, grow to maximum size somewhere in the middle, then taper back down (like a pointy cigar shape).

However, real airplanes need wings and other such things which add cross-sectional area. Therefore, the fuselage is usually narrowed where the wing joins it. This causes a problem when you want your airliner to carry as many people as possible, so rather than narrow the fuselage, designers sometimes add "Kuchemann carrots" (sp?) to the wings, to let the x-section area transition more smoothly. The old Convair 990 airliner has very prominent 'carrots for that reason (they also doubled as fuel tanks iirc). Modern jetliners get the same effect by careful design and placement of flap track fairings, engines, etc... I'm sure I left some things out, so if anyone w/ more aero-plane knowledge wants to chime in...

[Ricardo RW]

Thank you guys for explain that, surely I'm less ignorant now...

[DanSavage]

what are these things. I have searched every where I can for a name or explanation but have come up dry. Does any body out there know what they are? Sorry if this is in the wrong thread, I couldn't decide where to put it since I don't know the purpose of the the objects in question. Attached is a picture of what I am talking about, they are the 4 pod like things on the back of the wing. :confused: HELP ME! :confused:

FWIW, they're called canoes, for the obvious reasons.