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Currently the U. S. Department of Defense (DoD) exclusively uses potassium acetate (KAc)-based runway deicing fluids (RDFs) to deice and anti-ice military runways and taxiways. Commercial airports predominantly use KAc, but some also use RDFs composed of KAc plus propylene glycol (PG) or urea plus PG. Conventional RDFs have environmental concerns due to toxicity as well as material compatibility problems such as corrosion of aircraft carbon brake-pad components, cadmium-plated landing gear, and airfield lighting fixtures. Under the Strategic Environmental Research and Development Program (SERDP), Battelle tested a series of patented - bio-based RDFs to address these issues. Tests showed that the Battelle RDFs met the mandatory Aerospace Material Specification (AMS) 1435 requirements. These new RDFs have reduced ecotoxicity compared to currently used RDFs and are compliant with all other environmental requirements.

The purpose of this paper* is to describe research toward the application of Bayesian statistical methods to the calculation of system reliability The motivation for the suggested procedures stems from (1) the fact that Bayesian methods provide for the formal inclusion of all relevant information in reliability calculations and (2) the suitability of Bayesian methods to problems in which the probability distributions of interest change over time. In this report, suggested procedures are given for obtaining component reliability u estimates based on system test outcomes. Three possible test outcomes are considered: (1) success, (2) failure caused by known components, and (3) failure caused by unknown components. Using this procedure, substitution of new components or modification of the configuration of the system does not invalidate the test data accumulated up to the time of the changes.

THIS report of a survey of hydraulic packings, especially O-ring seals, covers friction studies, torsional strength tests, plasticizer development, a study of rubbers, molding technique, and spiral failure. The Institute is reported to be planning to conduct research work along the lines of cycling tests and studies of stress aging, compounding, and backup rings.