Stability and Strength of an Undercarriage Radius Rod: A Study of the Structural Design Criteria of an Articulated Radius Rod with an Internally Locked Jack

An undercarriage radius rod arrangement frequently employed comprises articulated members having a retraction jack locked internally in the down position to stabilize the system. The loads from the ground cases induced in the members are dependent upon the geometry of the system and also the clastic properties of the members and their respective airframe pick‐up structure. The conditions for structural stability are analysed and a method is given for determining the nominal offset of the radius rod knuckle to achieve an efficient strength‐to‐weight ratio for the structure.