Summary
The FAA proposes to revise an earlier proposed airworthiness directive (AD) that applies to certain Raytheon Aircraft Company (Raytheon) Model 1900, 1900C, 1900C (C-12J), and 1900D airplanes that do not have canted bulkhead Kit No. 129-4005-1 S incorporated. The earlier NPRM would have required you to repetitively inspect the canted bulkhead located at Fuselage Station (FS) 588.10 for cracks. If cracks are found that exceed certain limits, the NPRM would have required you to incorporate canted bulkhead Kit No. 129-4005-1 S as terminating action for the proposed AD repetitive inspection requirement. When Kit No. 129-4005-1 S is incorporated, no further action is required. The earlier NPRM resulted from numerous reports of multi-site cracks occurring in the canted bulkhead at Fuselage Station 588.10. The NPRM contradicts the FAA's policy to disallow airplane operation when known cracks exist in primary structure. You should have the kit incorporated anytime a crack is found andwe are revising the NPRM accordingly. Since this action imposes an additional burden over that proposed in the earlier NPRM, we are reopening the comment period to allow the public the chance to comment on these revised actions.