ED-344 provides guidance on assessing the suitability of insulation systems and their expected life under the combined effects of temperature, reduced air pressure, humidity, and other environmental stresses. Historically, electrical insulation test methods have been well defined for terrestrial applications. As air vehicle electrification is driving system and equipment designs to higher voltage levels, conventional aerospace test methods pertaining to electrical insulation may be inadequate to assess design suitability and life in an aerospace environment.