Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8-100 and -300 series airplanes. This proposal would require revising the Aircraft Log Book to correct the airplane Production Modification List; performing an inspection to determine which bonded skin panels on the airplane require bonding integrity inspections (BII); and revising the Airworthiness Limitations List of the Approved Maintenance Plan to include the BII requirements. This proposal also would, for certain airplanes, require repetitive ultrasonic bond inspections to detect disbonding of airplane skin panels, and repair, if necessary. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent damage to bonded skin panels to go undetected, which could result in failure of the bonded skin panels, and consequent loss of controllability of the airplane.