The object of this paper is to assess the efficacy of various measures, legal and physical, for the prevention of hijacking. I limit myself to examining the inherent limit-ations of different measures; and I propose to elaborate certain proposals, already made, for closing the ring. First, it is desirable to see what conclusions can be drawn from past events.

Reports from the airlines on hijacking incidents, during a period of three years from July 1968 to August 1971, have been recorded by IATA. Summaries of these reports have been made available to us, by courtesy of the Director General, through Sir William Hildred. I base my analysis in Tables A to D (see Appendix) on these records, for they are the only source of information available on the course of events and the consequences of each incident.