Peter Duniho wrote:

As far as I know, they are just fairings for the flap extension/retraction
mechanism.

If they are called anything other than "fairings", I don't know what.

The fairings that cover the flap tracks are sometimes called "canoes"
due to their general appearance.

I saw a display of the Airbus A-380 "canoes" once, they were *massive*.

Happy Flying!
Scott Skylane