Flight Deck Tie Downs

RT&L FOCUS AREA(S): General Warfighting Requirements TECHNOLOGY AREA(S): Materials / Processes OBJECTIVE: Develop an advanced non-corroding material to use in replacement DDG-51 FLT III Helicopter Flight Deck Tie Downs. DESCRIPTION: The U.S. Navy's DDG-51 Class Destroyer helicopter flight deck utilizes tie downs to anchor and secure the helicopters on the flight deck. While the tie downs should ideally last for the 40-year service life of the vessel, in practice they fail due to corrosion and often need replacement. The corrosion of a flight deck tie down is a grave hazard, as its failure at an inopportune time could cause extensive damage to valuable equipment and endanger the lives of the sailors aboard. Anti-corrosion coatings and coverings have not been effective at eliminating the problem. The Navy requires the development of an innovative, noncorroding material to replace the existing flight deck tie down. The development of a noncorroding material to meet the Navy need will require significant innovation to overcome several technical challenges, it must withstand saltwater immersion, exposure to industrial chemicals and jet fuel, and exposure to ultraviolet radiation; and be fire resistant and resistant to galvanic corrosion. Attaching tie downs of a new material class to the deck may require innovative welding techniques or advanced mechanical fastening methodologies. Whatever method is developed, it must be able to meet the same requirements as the current Navy tie down. Required maintenance must be able to be performed by Navy personnel. The joining method must also be watertight to the deck and prevent corrosion below the tie down. Research into noncorroding materials has identified materials that could potentially be developed to meet the Navy's need. Some of the more promising possibilities include Advanced Thermoplastic Composites, High Strength Metallic Glass, and Novel Metallic Alloys. However, no material within these categories has been adequately demonstrated to be a replacement for the strength and durability provided by steel. Thermoplastic Composites and Metallic Glass would most likely require mechanical joining. Novel Metallic Alloys might be easier to weld to the deck, but care must be taken to prevent galvanic corrosion in the steel. All these materials would need to pass extensive testing to demonstrate that they can replace the existing flight deck tie downs and withstand the repeated heavy loads required to anchor the ships assigned aircraft as defined in NAVSEA Drawing 803-1916300 Rev P (2013), Hull Standard Drawing Aircraft Securing and Engine Run Up Fittings , July 2013. Innovation will be required to reduce acquisition costs and produce a viable product for the Navy. PHASE I: Develop a concept for an innovative noncorroding material for Flight Deck Tie Downs that meets the requirements described above. Demonstrate the feasibility of the concept in meeting Navy needs and establish that the concept can be developed into a useful product for the Navy. Feasibility will be established by test of a material sample that will be analyzed in such a way that its failure mechanism will be representative of the larger product supported by finite element analysis. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build and demonstrate a prototype in Phase II. PHASE II: Based on the results of Phase I and the Phase II Statement of Work (SOW), develop and deliver at least one prototype tie down for evaluation to determine capability in meeting the performance goals defined in the Phase II SOW. Product performance will be demonstrated through prototype evaluation, modeling, analytical methods, and demonstration over the required range of parameters including numerous cycles. Perform an extended test in a maritime environment to refine the prototype(s) into a design that will meet Navy requirements. Prepare a manufacturing and development plan to transition the noncorroding tie down to Navy use. Support the Navy in transition planning and initiation of the Flight Deck Tie Down to Navy use. Develop installation and maintenance manuals for the tie down to support transition to the fleet. PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the tie down technology to DDG-51. Potential private sector uses for advanced noncorroding materials include both the automotive and aerospace industries. Other commercial applications include architecture and maritime use. REFERENCES: Mavhungu, S.T.; Akinlabi, E.T.; Onitiri, M.A. and Varachia, F.M. Aluminum Matrix Composites for Industrial Use: Advances and Trends. Procedia Manufacturing, Volume 7, 2017, pp. 178-182. https://www.sciencedirect.com/science/article/pii/S2351978916302086 Wu, Fu-Fa; Chan, K.C.[ Jiang, Song-Shan; Chen, Shun-Hua and Wang, Gang. Bulk Metallic Glass Composite With Good Tensile Ductility, High Strength and Large Elastic Strain Limit. Scientific Reports 4, Article number: 5302, 2014. https://www.nature.com/articles/srep05302