We had a write up today to inspect an aileron. It turns out that with all the hyd. pumps on, the suspect aileron was holding a slight down deflection. The crew didn't report any control difficulties on the inbound flight. They noticed the problem on preflight. The split between the trailing edge of the aileron and the trailing edge of the adjacent flap was some 0.600". Way beyond limits to say the least. The right aileron also exhibited the down deflection, but to a lesser degree. I left before any of the major teardown began, but I did hear that the rig pins were fitting fine so far.

I'm sure I'll find out the answer tomarrow, but any hunches as to what would cause such a large down deflection of the ailerons with no control difficulties? As far as I know, no work was recently performed in the vicinity that would require rigging. Other than needing to be re-rigged, what could cause drooping ailerons on a CRJ-200?