AD 98-20-19 63 FR 50755

This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-100 and -300 series airplanes, that requires inspections to detect corrosion on areas of the airplane structure where black film thermal insulation is used; repair, if necessary; and replacement of black insulation blankets with certain aluminized (silver) insulation. This amendment is prompted by reports of corrosion forming on areas of the airplane structure where the black film covers the thermal insulation blankets. The actions specified by this AD are intended to prevent degradation of the structural capability of the airplane fuselage and sudden loss of cabin pressure due to corrosion of the airplane fuselage structure.