Airworthiness Directives; Bombardier Model DHC-8-100, DHC-8-200, and DHC-8-300 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-100, DHC-8-200, and DHC-8-300 series airplanes. This AD requires revising the airworthiness limitations section of the Instructions for Continued Airworthiness by incorporating new and revised structural inspection procedures and new and revised inspection intervals for the longitudinal skin joints in the fuselage pressure shell. This proposed AD also requires phase-in inspections and repair of any crack found during any phase-in inspection. This AD is prompted by a report indicating that visual inspections were not adequate for detecting fatigue cracking in portions of the longitudinal skin joints in the fuselage pressure shell. We are issuing this AD to detect and correct fatigue cracking of the longitudinal skin joints in the fuselage pressure shell, which could affect the structural integrity of the airplane, and result in loss of cabin pressurization during flight.