Pacific Aerospace Cresco 08-600 and Fletcher FU-24 series aircraft.
This Continuing Airworthiness Notice (CAN) is issued to bring attention to a recent airworthiness concern reported to the CAA. Several Cresco and FU24 aircraft were found to have incorrect aileron rigging, apparently due to pilot preference. CAA Rule Part 91.603(a)(1) requires that an operator must ensure an aircraft is maintained in an airworthy condition, which is defined in CAR Part 1. Essentially an aircraft must be in compliance with maintenance requirements and in conformity with its approved type design.
This CAN is prompted by a report received by the CAA of certain Cresco 08-600 and Fletcher FU-24 series aircraft found with ailerons rigged too high, beyond the manufacturer’s specified limits. All aircraft in the fleet were subsequently checked, re-rigged as required, and returned to service.
An aircraft must be rigged in accordance with the applicable manufacturer’s Instructions for Continued Airworthiness. Any change to these settings and tolerances would have to be approved as a design change. The rigging position of the ailerons affects the spanwise loading of the wing, which will have been taken into account during the certification program to show structural integrity. Any change to this rigging could have an adverse effect on the wing structural strength.
Therefore, for an operator to maintain an aircraft in an airworthy condition, all flight controls must be rigged correctly in accordance with the current manufacturer’s specifications.
(Occurrence #18/2430 refers).
Operators/maintainers of affected aircraft should inspect the aileron rigging. If ailerons are found rigged incorrectly, then accomplish appropriate corrective actions per the manufacturer’s instructions before further flight.
