Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Bombardier Model DHC-7-100 series airplanes. This proposal would require repetitive high frequency eddy current inspections to detect cracks on the locking pin fittings of the baggage door and locking pin housings of the fuselage; repetitive detailed visual inspections to detect cracks of the inner door structure on all four door locking attachment fittings; and corrective actions, if necessary. In lieu of accomplishing the corrective actions, this proposal also would provide a temporary option, for certain cases, for revising the Airplane Flight Manual (AFM), and installing a placard. 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 detect and correct fatigue cracking of the baggage door fittings and the support structure, which could result in structural failure, and consequent rapid decompression of the airplane during flight.