Airworthiness Directives; Dornier Model 328-100 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-100 series airplanes, that requires replacement of certain hydraulic fuses of the landing gear with improved fuses. This amendment 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 this 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.