Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-1A11 (CL-600), CL-600-2A12 (CL- 601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604 Variants) airplanes. This proposed AD was prompted by a determination that the forward lugs of the flap hinge box might not conform to engineering drawings, which could result in premature fatigue cracking. This proposed AD would require revising the maintenance or inspection program to include new airworthiness limitations tasks; and measuring the forward lug edge distance of each flap hinge box, and inspecting for cracking and damage (i.e., deformation or bearing failure) of the forward lug edge of each flap hinge box, and repair if necessary. We are proposing this AD to detect and correct non-conforming flap hinge box forward lugs, which could result in failure of the lugs and detachment of the flap hinge box and consequent detachment of the flap surface.