Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Dornier Model 328-100 series airplanes. This proposal would require replacement of certain hydraulic fuses of the landing gear with improved fuses. This proposal is prompted by results of extended testing, which revealed that the hydraulic fuses of the landing gear failed to operate due to movement of the end of the spring within the fuses over the end of the flange of the spool. The actions specified by the proposed AD are intended to prevent such failure, which could result in external leakage in the brake lines downstream of the respective fuse and consequent loss of hydraulic fluid; this condition, if not corrected, could result in partial loss of the main hydraulic power supply.