In an aircraft in which servocontrols are supplied with hydraulic fluid under pressure by a main pump driven by an engine of the aircraft and, in the event of loss of said engine power, by an emergency pump which is driven by a dynamic air pressure turbine deployed from the fuselage of the aircraft,...http://www.google.de/patents/US5735116?utm_source=gb-gplus-sharePatent US5735116 - System for restarting an aircraft engine in flight after loss of engine power 
