This SAE Aerospace Recommended Practice (ARP) provides technical design and application information related to the generation@ distribution@ control@ and utilization of aircraft 270 V DC electrical power systems and support equipment. This document also provides references and definitions to permit comparisons of various electrical systems and components. Purpose: The purpose of this document is to consolidate industry recommended practices for 270 V DC systems and equipment to enable a common understanding of their specification@ design@ and use.