F100 wing rock
Not flown the Fokker for a couple of year due CAA medical Dept.
However roll in cruise is not vortex shedding, but mis-alignment of ailron system pfcu neutrals. Has been a problem since aircraft first in service with Air Europe. I think the man from Martinair fiddles with the RVDT's which transmit the neutral point of the ailrons back to the FCC's.