ANALYTICAL PREDICTION OF THE B-58A SPIN CHARACTERISTICS - PHASE II. CORRELATION OF ANALYTICAL MODEL SPIN PREDICTIONS WITH FREE FLIGHT MODEL TEST RESULTS,

This spin investigation is composed of freeflight model spin-entry and developed-spin tests, static and rotary force-model wind-tunnel tests to extreme angles of attack and sideslip, and an analytical program for prediction of high angle of attack motion. The second phase uses final, low Reynolds number aerodynamic data and deals with the correlation of analytical predictions of model motion with free-flight model test results. The objective is to determine the accuracy of analytical predictions of the model motions at extreme angles of attack so as to establish the level of confidence to be placed in the prediction of full-scale airplane motion. The free-flight model test program consisted of spin-entry catapult tests and developed-spin spin tunnel tests. Time histories of the motion of a 140-scale dynamically-similar model of the B-58A were obtained from raw test data transmitted by NASA. From comparison of analytical predictions of model motion with experimental time histories, it is concluded that analytical predictions of stall and spin-entry motion are quite adequate and valid. The developed-spin predictions are less accurate than those for spin-entry. However, they are representative of the developed-spin motion and the general levels of periods and amplitudes of the oscillations are acceptable. Authr