Demonstrate a Low Biochemical Oxygen Demand Aircraft Deicing Fluid

摘要

Aircraft deicing fluids are required to remove frozen precipitation from aircraft prior to flight, ensuring mission capability in winter conditions. Without effective removal of frozen precipitation, lift and control might be compromised and safety of flight is jeopardized. A problem with conventional fluids in use today, however, is that the primary component is propylene glycol (PG), which can exhibit a high biochemical oxygen demand (BOD) in receiving waters when it degrades. Thus the waste fluid can either threaten aquatic life or impede the effectiveness of waste water treatment processes, depending on where runoff from airfield deicing operations is directed. Because of this, some newer deicing fluid formulations feature the reduction or elimination of PG to assuage the BOD impact and reduce related runoff handling and permitting costs. The aim of this demonstration was to investigate whether one reduced PG aircraft deicing fluid, EcoFlo (and later EcoFlo II), was effective at deicing military aircraft while having no negative effects on flight performance, operational safety, and aircraft materials. EcoFlo and EcoFlo II have both been tested for compliance with Society of Aerospace Engineers (SAE) Aerospace Material Specification (AMS) 1424G, the commercial specification covering aircraft deicing fluids, and EcoFlo had been marketed for commercial aircraft use. Prior to the demonstration involving deicing with EcoFlo on operational Air Force aircraft, two laboratory evaluations were performed. The first consisted of observing the compatibility of EcoFlo with materials likely to be found on military aircraft but not commercial aircraft (i.e., not covered by SAE AMS 1424G). For most of the materials tested, EcoFlo was shown to either have no impact or no impact more significant than that of the baseline fluid, which is a conventional PG fluid. A few cases were identified where EcoFlo did not perform as anticipated; these instances were marked for future evaluation should the fluid be considered for aircraft featuring those specific materials.