Yes, they are.    

Spoilers are

small, hinged plates on the top portion of wings. Spoilers can be used to slow

an aircraft, or to make an aircraft descend, if they are deployed on both

wings. Spoilers can also be used to generate a rolling motion for an aircraft,

if they are deployed on only one wing. 

 In aeronautics, a spoiler (sometimes called a lift spoiler or lift

dumper) is a device that intentionally reduces the lift component of an airfoil

in a controlled way.  

. No, they are not. 

Depending upon the number of rows the riveted joints may be classified as  double riveted lap joint  or triple riveted lap joint only.

Depending upon the number of rows the riveted joints may be classified as single riveted lap joint, double or triple riveted lap joint etc. When multiple joints are used, the arrangement of rivets between two neighbouring rows may be of two kinds.

The riveted joints may be classified as single riveted lap joint