Document ID: chunk:federal_register_of_legislation:F2022L00572:body:0:p2
Version: federal_register_of_legislation:F2022L00572
Segment Type: other
Provision Reference: 
Character Range: 2889–4438

inspection fell due after 1 January 2001, perform the inspection 1 year earlier and repeat thereafter at intervals not to exceed 2 years.
                  Note:  The inspection interval has been reduced from 3 years to 2 years in accordance with Temporary Revision (TR) No. 63 of the AWL in the DHC Maintenance Program Manual PSM 1-8-7 for series 100 aircraft and TR No. AWL 3-70 of the AWL for the DHC Maintenance Program Manual PSM 1-83-7 for the 300 series aircraft.
                For requirements 1 and 2
             Disbonds beyond the local disbond limits defined in DHC document PSM 1- 8 -7A, Part 4, Section 55-00-01, as in force from time to time, must be repaired before further flight.
             This AD commences on 15 April 2022.
Background:  As a result of the inspection required by AD/DHC-8/51, a total of four aircraft with serial numbers close together were determined to have disbonds of the doublers and stringers on the upper and lower skin panels of the horizontal stabiliser. This discovery indicates that the bonding process was defective on a single batch of skins. The follow-up inspections of this Directive will ensure that no further problems exist in the above single batch or other batches of the bonded skin panels.
             Amendment 1 of this AD updates references to DHC NDT manual PSM 1-8-7A from part 5 to part 4. Transport Canada has issued an associated global AMOC AARDG‑2016/A48, which is available upon request from DHC.

David Punshon
Delegate of the Civil Aviation Safety Authority
7 April 2022