Premier I Hydraulic Failures Lead to Emergency AD

Four reported incidents of in-flight loss of hydraulic fluid led to an emergency AD being issued Friday for the 139 in-service Premier Is. None of the incidents led to any mishaps, according to Raytheon Aircraft. The problem has been traced to the failure of a hydraulic tube assembly in the left engine. The directive requires a visual inspection of the affected part before further flight and thereafter at intervals of 50 hours. Clamps must be replaced at each inspection, as well as the tube assembly itself if evidence of chafing, excessive vibration or hydraulic fluid leakage is found. Results of inspections must be submitted to the FAA and replaced tube assemblies are to be returned to Raytheon Aircraft. A company spokesman told AIN, “Our teams in the field have been contacting customers, and replacement tubing and clamps have already been manufactured; many are already in the field.” Additionally, he said the company is working on design changes. “Once implemented, the 50-hour inspection will be removed.”