Pressurized fluid feed system

In an on-board fluid system for aircraft comprising:

• a hydraulic fluid pumping device coupled to a motor of said aircraft;
• on-board user devices receiving hydraulic fluid from said hydraulic fluid pumping device through a connector feed pipe;
• a tank for receiving said hydraulic fluid from said user devices through a receiving pipe and returning said hydraulic fluid to said pumping device through a return pipe,
• the improvement comprising:
• a detachable ground hydraulic fluid feed system for said user devices;
• a first switching device disposed on said connector feed pipe between said pumping device and said user devices, said first switching device being able to connect said user devices either to said pumping device, or to said detachable ground hydraulic fluid feed system;
• a second switching device disposed on said return pipe between said tank and said pumping device, said second switching device being able to connect said tank either to said pumping device, or to said detachable ground hydraulic fluid feed system;
• detecting means on said tank for detecting the level of hydraulic fluid in said tank;
• a pressurized fluid source;
• and
• valve means disposed in a conduit means between said pressurized fluid source and said tank and controlled by said detecting means for introducing a pressurized fluid from said fluid source into said tank when said first and second switching devices connect said detachable ground hydraulic fluid feed system to said user devices and to said tank respectively and when the level of said hydraulic fluid reaches a predetermined threshold in said tank.