The development of aircraft engine fuels with improved safety characteristics is of considerable importance to both military and commercial users. Preliminary evaluation of such a fuel has recently been completed by the Allison Div. of General Motors Corp. under contract with the U.S. Army.This evaluation compared an emulsified mixture of JP-4 fuel in water with standard JP-4 jet engine fuel in the Model T63 gas turbine engine. The results of this testing on both bench test and full scale engine test demonstrated the feasibility of such a safety fuel in this or an engine of similar type. In fact, the fuel appears to have a very good potential for military application.