This SAE Aerospace Recommended Practice (ARP) contains methods used to measure the optical performance of airborne binocular Head Up Displays (HUDs). This document covers methods for conformal and non-conformal HUD systems that are intended for use in the cockpit by the pilot or copilot. The focus of this document is on displays that generate the HUD information using a cathode ray tube (CRT), however, the majority of the methods can be applied to other display technologies. These measurement methods are provided for testing to the requirements of AS8055.