Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to certain Bombardier Model CL-600-1A11 (CL-600) airplanes, CL-600-2A12 (CL-601) airplanes, and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) airplanes. The original NPRM would have required inspecting to identify the part number and serial number of the selector valves of the nose landing gear (NLG) and the nose gear door; and doing related investigative and corrective actions if necessary. The original NPRM resulted from reports of uncommanded partial retractions of the NLG. This action revises the original NPRM by adding airplanes to the applicability.
We are proposing this supplemental NPRM to prevent internal leakage of the selector valve, which, under certain conditions, could result in an uncommanded retraction of the NLG with consequent damage to the airplane and possible serious injury to ground personnel.