A METHOD OF REMOVING HYDRAULIC FLUID FROM AN AIRCRAFT HYDRAULIC SYSTEM, AN AIRCRAFT HYDRAULIC SYSTEM, AND AN AIRCRAFT

摘要

A method of removing hydraulic fluid from an aircraft hydraulic system. The hydraulic system comprises a hydraulically actuated mechanism that is actuated by an electrohydraulic servo valve, a hydraulic fluid port through which hydraulic fluid can escape, and a hydraulic fuse with a closed state and an open state between the electrohydraulic servo valve and the hydraulic fluid port. The hydraulic fluid port is opened, and then the activation of the electrohydraulic servo valve is controlled to force hydraulic fluid to escape from the hydraulic system via the hydraulic fluid port, the control being so that the hydraulic fuse does not enter and remain in the closed state.