Transport Canada CF-2020-29R1

Supersedes CF-2020-29 to mandate new certification maintenance requirement (CMR) tasks while giving credit for initial and repetitive inspections already performed, to change the applicability to exclude airplanes that have the CMR at delivery, and to remove a reporting requirement. The original AD stemmed from two in-service findings where both the left-hand and right-hand elevator torque tube bearings were contaminated with sand and corroded, restricting free rotation. Free rotation of the elevator torque tubes is required for elevator operation. AD CF-2020-29 was issued to mandate visual inspections of elevator torque tube bearings as well as functional tests of the elevator control system, to detect and replace contaminated bearings. Since then, the data collected has been used to validate inspection intervals, which have been integrated into new CMR tasks.