Hydraulic Power Loss Prevention on Commercial Transport Aircraft-Available Technology

As most modern large commercial transport aircraft use fully hydraulic powered flight controls, the loss of all hydraulic power is a catastrophic event. Loss of all hydraulics may be caused by either external or internal events. These are rare in occurrence and sometimes difficult to predict. Available options for preventing total hydraulic loss fall into two categories: system installation/redundancy options and system shutoff devices. This paper discusses the advantages and limitations of each approach and how they differ depending on whether they are applied to a new airplane or are used to retrofit older airplanes.