Taehun Seung 
Self-Induced Fault of a Hydraulic Servo Valve [PDF ebook] 
A Possible Cause for Hidden Malfunction of Aircraft’s Systems

Introduction.- Topics and arrangement of this report.- Occasion for investigation, brief description of the occurrence.- Appraisal and fundamental contemplation for a pressure controlling servo valve.- Existence of a self-induced fault of a two stage servo valve – Hypothesis.- Experimental investigation – Test execution and results.- Reconstruction of the entire fault working mechanism – interim conclusion.- Additional reflections / Supplementation of contemplation.- Conclusion.

Dr.-Ing. Seung is an Aircraft Engineer with emphasis on Aerodynamics, Flight Mechanics, System Technology and Hydraulics. He is also a Public-Funding Manager for Aeronautics Research Programs of the German Federal Ministry for Economic Affairs and Energy.