Transport Canada CF-2020-35

Requires the use of improved aircraft maintenance manual procedures when performing maintenance involving one or both roll control input modules (RCIM). Prompted by several in-service reports of a single RCIM being installed incorrectly, and one report of both RCIMs being installed incorrectly. An investigation has determined that it is physically possible for an RCIM to be installed and zeroed 180 degrees from its intended design installation orientation. If both RCIMs are installed incorrectly, a misrigging condition occurs, causing the multi-function spoilers to deploy opposite to the roll command. Misrigging of these spoilers could lead to loss of control of the airplane.