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An evaluation has been made of the angle-of-attack range at which experiments on slender sharp cones can be performed using half models. The evaluation was based partly on a comparison of surface flow patterns over full and half models, partly on the measurement of the static side force on full models at zero yaw, and partly on a comparison of oscillatory pitching results obtained with full and half models. Most of the results were obtained at a Mach number of two in the range of angle of attack between 0° and 30°, but the static side force was also measured at Mach numbers between 0.5 and 0.8. In all cases investigated it was found that up to an angle of attack of at least 15° no significant side force could be detected on full models, and that the pitch damping results and the surface flow patterns (with the exception of the primary attachment line) obtained on full and half models were in close agreement. The half-model technique appears therefore suitable for oscillatory experiments on slender cones (and probably on other similar geometries) at angles of attack at least up to 15°, at low supersonic speeds. Application to higher speeds, however, may very well require special corrections for tunnel-wall or reflection-plate boundary layer.Nomenclature (pitching moment)/(q57) d'Cm/dd, static pitching moment derivative dC m /d(l6/2V), pitch damping derivative (normal force)/(#S) dC N /dd (side force)/(#S) TIT// V, reduced frequency model length freestream dynamic pressure base area of the model freestream velocity distance of axis of oscillation from cone apex (mean) angle of attack angle of oscillation in pitch about a fixed axis, and its first derivative with respect to time cone semiangle oscillation frequencyPresented as Paper 72-1015 at.'the AIAA 7th Aerodynamic Testing Conference, Palo Alto, Calif.

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