Description / Abstract: This document contains MOPS for Strapdown Attitude and Heading Reference Systems (AHRS). It is intended for equipment that does not use gimbaled sensors and for equipment that outputs attitude (pitch and roll). It also addresses functions of heading, turn, slip and the display of this information. This document does not specify the format of data outputs but does specify equipment characteristics that should be useful to designers, manufacturers, installers and users of the equipment