The association of Harold Roxbee Cox with the Air Registration Board began in 1938 (the year following its formation) with his appointment as its first chief technical officer — a post to which he was eminently suited by virtue of his experience and already formidable reputation in a wide range of technical aspects of aviation. Interrupted by the war, his service to the ARB was renewed first as consultant and member of the board, later (as Sir Harold Roxbee Cox) as its vice chairman and finally (as Lord Kings Norton) as its chairman.

A methodology has been developed to integrate the vulnerability discipline into the conceptual/preliminary design process of combat aircraft. An interactive and programmable solid modelling Computer Aided Design (CAD) system is used to generate a CAD solid model of the aircraft’s critical components. The aircraft’s components’ sizes and shapes are pre-defined by a conceptual/preliminary design synthesis computer model. A systematic Child-Parent assembly process is used to model the aircraft vulnerability, by defining the criticality degree of each component in the aircraft assembly. Solid Modelling CAD techniques have been modified to develop techniques to perform the two main standard vulnerability assessments, namely the shotline and vulnerable area methods.

The Air Registration Board came into being as a result of the work of the Gorell Committee. It was incorporated in February 1937 and started work on April 1 of that year. The chairman of the board was Sir Maurice Denny, and there was a very small staff— reflecting the limited duties given to it initially. By early 1938 these had grown somewhat — so, for example, the board was authorised to recommend changes to regulations and requirements and it also started to investigate the design of prototype aircraft (cautiously, the Air Ministry limited it to investigations of aircraft weighing less than 10,000lb.).