Originally Posted by
Sunfish
That is one of their purposes. The others include; preventing interference between control surfaces at the limits of travel, preventing the control surface from interfering with secondary structure (eg; fairings), preventing the control circuit from moving outside design mechanical limits (eg; linkages going oversquare or interfering with other structure). These are all potential causes of jamming.
and FAR 23 requires limit load tests of control surfaces. I recall an aileron jam a few years back where the control interfered with adjacent fixed structure.