The arresting gear system on an aircraft carrier utilizes slippers and bearing materials between moving components. Presently, these bearing materials are a phenolic composite reinforced with a cotton textile and friction modified with graphite. The purpose of this proposal is to find a replacement material. The reasons for replacement of the material include: availability of the existing material, swelling from contact with ethylene glycol, wear debris damage to associated seals, and wear life. This application presents several challenges, most notably related to the wide range of pressures and velocities across the various slipper applications. There are nine slipper configurations in the system. Each has its own set of operating characteristics. The surface contact pressure varies from 10psi to 530psi. The contact speed varies from 0 to 540 in/s. The sliding distance can be up to 112 in. The sliding surface finish (Ra) varies between 16 micro-inches and 125 micro-inches. The surface may have any combination of dry, greased, ethylene glycol, and environmental contamination. Using wide spectrum wear testing as a measurement basis, a number of materials, both commercially available and novel, will be compared with the existing bearing material. An alternate, or alternates, will be selected or developed, based on wear life over the spectrum of operating conditions that simulate, as closely as feasible, the field operating conditions.
Benefit: The arresting gear is essential to aircraft operations, a poor performing arresting gear can affect the effectiveness of flight operations until the gear mechanism is repaired. In addition, slipper replacement can be a labor intensive, time consuming and costly process. Accordingly, an improved slipper material that increases service life can support a reduction in carrier operations downtime, particularly unscheduled downtime resulting from premature slipper failure, as well as meaningful cost reduction. Tribis and Columbia Industrial Products (CIP) anticipate development of a high performance composite bearing material with superior resistance to ethylene glycol contamination. Such a product is expected to be attractive for several of CIPs already established market positions including heavy industrial, agricultural equipment, marine, oil & gas, and hydro-electric industries. A polymer based ethylene glycol resistant material with outstanding wear resistance will have commercial potential as a cost reducing substitute for more expensive, non-polymer bearing materials (e.g., bronze) that are specified when and where ethylene glycol concerns are present. The developed material can also have market potential as a performance improving substitute in appropriate current and past applications of the current material, including appropriate Department of Defense applications.
Keywords: Arresting gear, Arresting gear, slipper, Bearing, tribology, Composite Bearing Material
