I've never flown the type, but my understanding is the ATR has a clutch mechanism in the elevator control run to protect against control jams. If the differential force between the two control columns exceeds about 52kg, it will decouple the two control columns and each pilot then flies their half of the elevator separately. It's not designed to be recoupled in flight...
Last edited by muffman; 29th Apr 2014 at 03:13.
Reason: Removed speculation