This SAE Aerospace Recommended Practice (ARP) provides performance criteria for altitude alerting devices and systems. These devices can be self-contained or receive remote altitude information and can have integral or remote barometric corrections. Only the generation of the alerting signals is covered by this recommended practice and not the details of the visual or audio alerts operated by these signals. It is recommended that the systems operational correspondence between the selected altitude settings of the altitude alerting device an the altitude level indication normally used to control the aircraft should not exceed ?50 ft RSS throughout the operating range of the device.