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Flight tests have been conducted at Wright Field on the P-47D airplane, AAF NO. 42-26167, at the request of the Power Plant Laboratory, Engineering Division. These tests were made to determine the increased performance of the airplane using the higher powers allowable by use of 44-1 fuel as compared with powers allowable with the standard fuel, grade 100/130, Spec. No. AN-F-28. From 15 April to 30 June 1944 approximately 30 hours were flown by Captain R. B. Johnston.