It is already 6 years ago since the Hamburg University of Technology organized the 1st International Workshop on Aircraft System Technologies AST 2007. After further very successful meetings in 2009 and 2011, the 4th event of this series, the AST 2013 has been organized. The proceedings of the workshop comprise more than 40 highquality contributions which were selected from a call for papers. The contributions presented at the workshop address the fields of Airframe Systems and Equipment, Cabin and Comfort, Information and Communication Management as well as Materials and Production. In the first chapter dealing with Airframe Systems and Equipment, topics such as flight control, electromechanical actuator technology, energy-autonomous cabin, energy optimization, as well as cooling systems and thermal control are discussed. Additional papers are related to special areas, such as more electric aircraft, fuel consumption, grid protection, electric taxiing, or fire protection. The topics with respect to Cabin and Comfort are treated in the second chapter. Starting with investigations on cabin interior layout and modularization, a number of different comfort-related issues are discussed as well. Thereby, a special focus is on cabin interior acoustics and climate control / thermal comfort, including special topics like, e.g., active structural acoustic control or cabin air filtration. Chapter three Information and Communication Management covers different aspects of future cabin networks. Actual topics like modular architectures and near field communication are discussed with respect to an application inside the aircraft cabin. The last chapter is devoted to Material and Productions. On the one hand, several contributions dealing with efficient production techniques and automated assembly are included. On the other hand, topics related to inspection, damage location, and nondestructive testing are covered. For practicing engineers and scientists working in one of these areas, the proceedings will be a valuable source of information.