Nonmetallized double-base propellant and ammonium perchlorate (AP)/binder sandwich combustion were studied in standard and high acceleration environments in order to determine the acceleration sensitive combustion mechanisms. Experimental techniques used were high speed motion pictures, two-color schlieren, and centrifuge mounted combustion bombs. It was found for double-base propellant that the temperature increased continuously from the surface into the visible flame. Acceleration induced burning rate augmentation occurred and resulted in elimination of the visible flame. A modified surface or subsurface zone is proposed as the acceleration sensitive combustion mechanism. AP/binder sandwich combustion was also found to be acceleration sensitive with binder flow-AP interactions proposed as the mechanism.