3
 
      country to another. A country dependent upon its trade routes 
      must provide large numbers of aircraft for trade defense: another 
      country with large land forces must devote a correspondingly 
      large proportion of its aircraft to Army Co-operation duties. 
      Even a numerical comparison of bomber forces will be misleading 
      unless due weight is given to such factors as range and bomb 
      load. In fact, in comparing bomber forces total bomb-lift is 
      probably a better yardstick than numerical strength. These considerations 
      show that the problem of defining what is necessary for an adequate 
      air defense system is not one to be resolved by a simple reference 
      to numbers of first line aircraft; and this fact should be taken 
      into account in connection with the outline of the British program 
      set out below.
 
      
 
 
6. The British Program.
 
      
 
 
By the spring of 1940 the Metropolitan* Air Force will have 
      reached a strength of 2,370 first line aircraft. Behind this 
      first line there will be reserves amounting to nearly 150% and 
      all aircraft (including reserves) will be of modern types. The 
      first line will be organized in 138 squadrons:- 70 bomber squadrons, 
      40 fighter squadrons, and 28 squadrons of Army Cooperation and 
      General Reconnaissance aircraft. In addition some 47 Balloon 
      Barrage squadrons will have been created.
 
      
 
 
By the same date the Royal Air Force abroad will consist of 
      some 500 first line aircraft stationed at the vital strategic 
      points on the Empire trade routes. The overseas squadrons will 
      also be equipped with war reserves.
 
      
 
 
Mention should also be made of the Fleet Air Arm which is 
      expected to reach a first line strength of about 500 early in 
      1940. The exact strength will, however, depend on the rate of 
      commissioning of ships. * i.e. that located in the United Kingdom