Why Parts Cleaning Matters in Part 145 Maintenance
In the world of aviation maintenance, efficient cleanliness is far more than aesthetic—it’s essential to aircraft performance, repair station operations, and regulatory compliance. For certified Part 145 repair stations, the cleaning process directly influences aircraft airworthiness, component longevity, and overall maintenance quality. Whether removing carbon from turbine components, degreasing hydraulic manifolds, or preparing assemblies for non-destructive testing (NDT), a reliable cleaning process is foundational. As components become more complex and regulatory scrutiny increases, the demand for robust, repeatable cleaning practices grows with it.
Understanding the Regulatory Context
Part 145 refers to the set of regulations governing repair stations approved to perform maintenance and alterations on aircraft and components. Under the FAA (14 CFR Part 145) and EASA (EU Part 145), certified facilities are required to:
• Follow manufacturer-approved maintenance and cleaning procedures
• Use equipment that is suitable, calibrated (if required), and maintained
• Ensure that maintenance tasks—including cleaning—are documented and traceable
Cleaning is not an isolated task; it is part of the maintenance ecosystem. Inadequate or incorrect cleaning can result in extended turnaround times, premature wear, or even in-flight component failure.
Parts Cleaning Requirements in Aviation MRO
Aircraft components encounter a wide range of contaminants, including:
• Hydraulic and turbine oils
• Carbon and soot deposits
• Sealants and adhesives
• Dust and metallic particles
• De-icing fluids and corrosion inhibitors In response, MRO facilities must ensure cleaning processes that are:
• Thorough, to meet cleanliness standards for inspection and service
• Compatible with aerospace materials (e.g., aluminum, magnesium, titanium)
• Repeatable and documented, to support traceability and quality audits
• Compliant with safety, environmental, and OEM requirements
• Efficient to provide a cost-competitive service Some component maintenance manuals (CMMs) or OEM service bulletins will prescribe specific cleaning methods and fluids—further tightening the requirements.
Types of Cleaning Technologies
Solvent-Based Systems
• Effective for oils, greases, and organic contaminants
• Require proper ventilation and waste handling
• Subject to increasing environmental regulation
Aqueous-Based Systems
• Use water-based detergents and heated cleaning
• Often more environmentally sustainable
• Require attention to pH, temperature, and rinse cycles
• Bioremediation systems that “self clean” are possible
Manual Parts Cleaning
• Often used for smaller or delicate parts
• Dependent on operator technique and attention
• Limited consistency for high-throughput environments
• High flexibility for changing demands
Immersion Parts Cleaning
• Usually have a lift arm option for easy load/unload
• Multi-stage (e.g., wash, sonic, rinse, dry, dip) can be available for more complicated procedures
• Pump and lift agitation flush contaminants away from parts, increasing cleaning speed and efficacy
Ultrasonic Cleaning
• Ideal for parts with internal passages or intricate geometries
• Uses cavitation (implosions) to remove embedded contaminants
• Often used for carbon removal
• Care is needed for fragile parts, especially ceramics
Spray Cabinet Washers
• Automated and enclosed systems for large or high-volume parts
• Consistent cleaning results with less labor input
• Effective for landing gear, actuators, and structural components along with ground support equipment
Equipment Selection Considerations
When choosing a cleaning system for Part 145 operations, MROs should evaluate:
• Part types and materials: Are the washer and chemistry safe for all alloys in use?
• Cleaning throughput: Can the system keep up with maintenance flow, both in terms of potential part sizes and throughput?
• Fluid compatibility: Does it support the chemistries required by OEMs?
• Footprint and facility constraints: Will it fit into the current workspace?
• Filtration and fluid management: Can it reduce disposal frequency?
• Documentation: Can cleaning be integrated into digital or paper QC records?
Best Practices for Implementing and Maintaining Cleaning Systems
To ensure performance and compliance, MROs should consider:
• Regular fluid testing and replacement schedules - cleaning efficiency will drop as baths become saturated. Work with your equipment and chemistry providers, along with your disposal company, on a schedule.
• Automated v manual - what is your tradeoff with paying more for an automated or semi-automated system versus letting current employees clean parts in their excess time?
• Operator training on safe and correct washer usage. What level of worker is using the equipment?
• Inspection and maintenance of washer components - Pumps, filters, heaters, and controls all must be working properly in order to achieve consistent results.
• Documentation of cleaning steps as part of work orders or inspection records. This includes process variables such as temperature, pH, cleaning time, and any non-washing steps such as drying
• Review of OEM manuals and regulatory updates for approved cleaning methods and chemistries
Aligning Cleaning Infrastructure with Part 145 Demands
In the context of Part 145 aviation maintenance, parts cleaning is not a background task—it’s an essential quality process. As aviation systems become more complex, and oversight more stringent, having the right cleaning technology and procedures in place is essential. Facilities equipped with robust cleaning systems—matched to their regulatory, environmental, and operational needs—will be better positioned to maintain compliance, improve inspection outcomes, and extend component life. Whether adopting a new system or refining an existing one, understanding the role of parts washers in this ecosystem is a key step toward more efficient, safer, and compliant maintenance operations.
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