68 



THE DEVELOPMENT OF WEAPONS SYSTEM REQUIREMENTS 



Fig. 2-14 Plan for Analysis of AEW System Requirements (Step 2 of Master 

 Plan — Fig. 2-2). 



The number of interceptors A^ which can be directed against the separate 

 elements (single surviving targets) of the 20-plane raid during the air 

 battle is selected as the criterion for judging AEW system performance. 



As already shown (Paragraph 2-9) the required number of interceptions 

 depends upon the kill probability per interceptor. If we assume a value 

 of 0.50, the required number of interceptions is 40 (Fig. 2-11). T\\& task 

 force early warning range needed to meet this requirement is 255 n.mi."* 

 This is one possible combination of parameters satisfying the operational 

 requirement and the interceptor availability limitation. We may select 

 this combination as a design point — keeping in mind that it is 

 possible to trade off interceptor effectiveness and number of interceptions 

 should subsequent analysis indicate this to be desirable. For purposes of 



''More correctly, the specification of detection range should include the required minimum 

 probability of obtaining that range, e.g. 90 per cent probability of detection when the target 

 has closed to 255 n.mi. This point is covered in more detail in Paragraph 2-12. 



