I have been asked to give you some idea of the activities which occupied me for four years of the war, namely, my duties with the Admiralty. For obvious reasons it is not possible for me to give in detail many of my impressions or the problems that arose in the work which was mainly directed to the end of securing the right number of the right type of Naval Aircraft at the right place at the right time. In practice the emergency of the problem precluded the use of sophisticated methods, and recourse had to be made to practical measures designed to provide a fair approximation to the answer sought.

As an instance of the actuarial nature of the problem involved it may be noted that the life of an aircraft is made up of three components:

(a) a period when, although serviceable, the aircraft is ineffective through being in transit, etc.,

(b) a period when it is effective and in use (including that in ‘ready reserve’), and

(c) a period when the aircraft is ineffective while undergoing repair, etc.