Aircraft undercarriage suspension

An aircraft undercarriage for supporting an aircraft structure comprising:

• a ground contacting element;
• a variable length liquid-filled strut operatively connected to the aircraft structure and the ground contacting element to support a proportion of the weight of the aircraft structure;
• resilient means for controlling the length of said strut in dependence on the load supported thereby;
• a first liquid-filled chamber in said strut from which liquid is displaced by upward movement of the ground contacting element relative to the aircraft structure;
• a second liquid-filled chamber closed by a movable wall acting on said resilient means in a direction to increase the load thereon under the pressure of liquid displaced from said first chamber;
• a valve block;
• first and second flowpaths defined by the valve block connecting said first chamber and said second chamber;
• first flow restricting means in said first flow path and second flow restricting means in said second flow path to damp movement of the ground contacting element relative to the aircraft structure;
• a selector valve in the valve block operable to direct the displaced liquid selectively through each of said flow paths;
• and means responsive to aircraft landing to control said selector valve such that said first flow path is operative while the aircraft is landing and the second flow path is brought into operation when the aircraft is taxiing.