Twenty-six unused fighter aircraft were made available for use in an investigation to determine the fatigue characteristics of a typical fighter airplane. The primary purpose of this investigation was to obtain fatigue data on full-scale structures for use in designing new aircraft. The aircraft were disassembled into major components: wing, horizontal tail, vertical tail, nose landing gear, and main landing gear. Constant-amplitude and variable-amplitude tests were performed on the various components to determine: (1) the degree of scatter, (2) the effect of cumulative damage and the validity of various cumulative damage hypotheses for full-scale structures, (3) the effect of randomization of the load sequence within a spectrum block, (4) the effect of superimposing landing loads on a flight load spectrum, (5) the effect of prestressing, and (6) the effect of varying the mean and alternating loads. A discussion of the test results and their significance for future design use is included.