AD 99-23-05 64 FR 61478

This amendment adopts a new airworthiness directive (AD), applicable to all Bombardier Model DHC-8-101, -102, -103, -106, -201, - 202, -301, -311, and -315 series airplanes, that requires repetitive detailed visual inspections and high frequency eddy current inspections to detect cracking of the wing upper skin and ladder plates at over wing access panels between certain stations; and repair, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct fatigue cracking of the wing ladder plates, which, if not corrected, could reduce the structural integrity of the wing.