Qualification, Demonstration, and Validation of Non-Hazardous Solvent to Clean Composite Aircraft Components

Dr. Raymond Meilunas | Naval Air Warfare Center – Aircraft Division



The objective of this project is to qualify and transition NAVSOLVE™, an environmentally compliant cleaning solvent, for the efficient removal of hydraulic fluid and other contaminants from Department of Defense (DoD) aircraft composite structures. Existing compliant solvents are ineffective and inefficient at removing these contaminants, particularly when there has been ingress into the honeycomb core, which often precludes repairs of composite structure resulting in high scrap rates. Declining budgets, high costs for composite structure, inconsistent availability of spare parts, and environmental regulations restricting use of more effective high volatile organic compound (VOC)/hazardous air pollutant (HAP) solvents are severely impacting DoD aircraft platforms as they increase use of these lightweight structural materials.

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Technology Description

To meet emerging environmental regulations, the Aerospace Materials Division at Patuxent River developed a new HAP-free cleaner known as NAVSOLVE™ that meets the performance requirements of MIL-PRF-32295A Type II for metal components. There is currently no cleaner qualified to the specification that has been validated for use on structural composites. This project will evaluate the compatibility of NAVSOLVE with common polymer matrix composites, adhesives, and core materials individually and as assembled in a structure; measure the efficiency of removing hydraulic fluid from composite surfaces and from within core structure compared to existing cleaners; demonstrate post-clean repair capability in the lab and at field sites; document processing steps for inclusion in Local Process Specifications (LPSs) and Structural Repair Manuals (SRMs); and establish test methodologies for inclusion either in MILPRF-32295 or other documentation for qualification of NAVSOLVE and future products for use with composite structure.

In the first phase of the project, extensive structural composite coupon-level testing will be performed to verify that long-term exposure to NAVSOLVE does not degrade mechanical properties and/or repair capability of composites or the adhesives and core materials used for fabrication and repair of structures. The focus will be on composites and repair materials used in next generation aircraft including the F-35, F-22, V-22, and H-53K. Tests will be conducted on specimens exposed only to NAVSOLVE and to those exposed to hydraulic fluid followed by cleaning with NAVSOLVE. The second phase of the effort will include field demonstrations performed at Navy and Air Force aircraft maintenance sites with the focus on removing hydraulic fluid contamination from composite components. In the final phase of the project, MIL-PRF-32295 Type II will be updated with composite cleaning requirements to allow qualification of NAVSOLVE and support transition of the cleaner into existing operations & maintenance (O&M) procedures (LPSs, SRMs) for use on fixed and rotary wing aircraft for both metal and composite part applications. A cost benefit analysis will be performed to assess the cost savings incurred using NAVSOLVE to decrease hazardous waste streams, decease part cleaning times, and reduce composite part scrap rates.

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The transitioned technology will provide an efficient and environmentally compliant means to clean composite aircraft components. Savings will be realized not only through reduced costs of hazardous waste disposal associated with current solvents but also through an increased ability to clean and repair contaminated composite parts resulting in reduced scrap rates and associated disposal and replacement costs. Use of NAVSOLVE will permit compliance with current and emerging Environmental Protection Agency, State, and local government regulations on solvents, improve mission readiness by reducing aircraft downtime, and reduce the environmental waste footprint of scrapped composite parts due to failed bonded repairs. (Anticipated Project Completion - 2016)

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Points of Contact

Principal Investigator

Mr. Raymond Meilunas

Naval Air Warfare Center - Aircraft Division

Phone: 301-342-8064

Fax: 301-342-8062