Boeing 777 high lift control system

The Boeing 777 high lift control systems (HLCS), a state-of-the-art microprocessor-based system that provides fly-by-wire control, protection, and built-in-test and maintenance access functions for the leading edge slats and trailing edge flaps drive and actuation systems, is discussed. This system is designed to take advantage of technologically proven concepts as well as judicious application of new concepts in response to market demands, airline customer input, and a thorough review of lessons learned from previous aircraft programs. The purpose of the HLCS, the wing high lift devices it controls, the HLCS components, its three modes of operation, automatic functions, and system failure protections are described. The use of the EASY5 engineering analysis program developed by the Boeing Company to model dynamic systems in both the time and frequency domains for modeling mechanical and hydraulic portions of the high lift system is discussed