EASA AD US-2019-14-02
Hydraulic Power - Pressure Module Check Valves - Inspection
Summary
Federal Register Volume 84, Number 141 (Tuesday, July 23, 2019) - Airworthiness Directive 2019-14-02 is a final rule issued by the Federal Aviation Administration (FAA) addressing all Boeing Company Model 737 series airplanes. This directive requires inspection of the hydraulic power pressure module check valves, specifically targeting certain aluminum check valves prone to structural fatigue cracks. The affected parts include Parker pressure module check valves, part number H61C0552M1.
What Changed
This new airworthiness directive introduces mandatory inspections to identify the part numbers of the four hydraulic systems A and B pressure module check valves on Boeing 737 series airplanes. It also mandates on-condition actions, including replacement of affected Parker check valves with Crissair check valves if fatigue cracks are found. The directive clarifies that installation of winglets under specific Supplemental Type Certificates does not affect compliance.
Why It Matters
This directive is critical for aviation professionals because structural fatigue cracks in the aluminum pressure module check valves can lead to separation of the check valve head from the body under hydraulic pressure, posing safety risks including potential injury to maintenance personnel. Operators and maintenance organizations must ensure compliance to prevent unsafe conditions and maintain airworthiness. The directive also impacts parts management since affected parts are considered rotable and could be installed on multiple aircraft over time.
What To Do
Operators of Boeing 737 series airplanes must inspect the four hydraulic systems A and B pressure module check valves to determine their part numbers by August 27, 2019. If Parker check valves, part number H61C0552M1, are found, they must be replaced with Crissair check valves, part number 1C4196. Compliance with the inspection and any necessary replacements is mandatory by the effective date of August 27, 2019.
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