OEM Hydraulic System Maintenance and Repair
Why Are Quality and Authenticity of Hyd raulic Components Critically Important?
Aircraft hydraulic systems lie at the heart of many vital flight operations. These systems are responsible for controlling and actuating large and sensitive
components such as flight control surfaces (flaps, ailerons, rudder) , landing gears, brakes, and in some models , cargo doors . Given the high pressure,
heat, and impacts caused by sudden load variations, these systems must be maintained to the highest standards.
The OEM (Original Equipment Manufacturer) approach to hydraulic system maintenance means full adherence to official manuals, use of specific testing
tools, and components directly approved by the aircraft or hydraulic system manufacturer . This is the only way to guarantee the safety , reliability , and
performance durability of these critical systems.
Main Components of the Hydraulic System and Maintenance Challenges
Aircraft hydraulic systems consist of complex components:
Hydraulic pumps: Supply pressure throughout the circuit.
Flow and pressure control valves: Guide and manage fluid flow.
Actuators and cylinders: Move the mechanical flight components.
Filters and reservoirs: Ensure fluid cleanliness and volume.
Pipes and hoses: Subject to vibration and temperature variation.
These components operate under pressures exceeding 3000 PSI , and even the slightest contamination , crack , leak , or performance issue can lead to
system failure.
What Does the OEM Approach to Hydraulic Maintenance Mean
OEM-standard hydraulic system maintenance means:
Use of OEM-approved CMMs (Component Maintenance Manuals): Each component has precise disassembl, inspectio, tolerance measurement
, and reassembly instructions.
Utilization of OEM-certified spare parts: From O – rings and seals to valves and spools , all parts must come from the original manufacturer or be
OEM-approved.
Functional testing according to OEM data: Working pressure, permissible leakage, response time, and even system noise must align precisely with
OEM standards.
Key Benefits of Using OEM Parts and Manuals
Safety and Reliability
OEM components are designed exactly to original specifications and undergo rigorous environmental and functional testing . This ensures flawless
operation under real flight conditions — such as extreme temperature shifts or sudden maneuvers.
Longer Lifespan and Lower Long-Term Costs
While OEM repairs may seem more costly in the short term , their durability and reduced failure rates mean much lower overall lifecycle costs .
Regulatory Compliance and Audit Readiness
Aviation authorities like the FAA and EASA require complete documentation and traceable components to issue and renew airworthiness certificates.
OEM parts come with serial numbers and full manufacturing records, simplifying inspections and certification processes.
What Are the Risks of Not Following OEM Standards?
Some repair centers or smaller airlines may turn to non-OEM or even uncertified refurbished parts due to cost pressures . However , this choice can
have serious consequences:
Increased failure rate and AOG incidents: The hydraulic system is critical—any fault can ground the aircraft.
Audit failures: Use of uncertified components may lead to aircraft being grounded during periodic audits until the issue is resolved.
Loss of reputation for the airline or MRO: Operators with safety or audit issues may struggle in charter and aircraft leasing markets.
The Importance of Choosing OEM-Authorized MRO Centers
Many hydraulic system manufacturers (such as Parker , Eaton , Moog , Liebherr) only authorize specific repair centers to service their components .
These facilities have access to calibrated tools, proprietary manuals, original spare parts, and even OEM diagnostic software. This ensures that after
repair or overhaul, the component meets the original factory quality standards.
Conclusion
Aircraft hydraulic system maintenance using the OEM approach is more than an operational or financial decision — it’s a critical requirement for
passenger safety, airline credibility, and compliance with stringent global regulations. Using OEM parts and manuals ensures that sensitive hydraulic
systems perform in the next flight exactly as originally designed.
Investing in OEM repairs is, in fact, an investment in a safer and more sustainable future for the aviation industry.
Contact us for consultation and purchasing