Accommodation for the C.S.D.I.C. Memorandum by the J.I.C.

4. We have been informed by the Engineer-in-Chief of the General Post Office that the disturbance caused by flying in the vicinity of these aerodromes would make it quite impossible for the Centre to operate. Experience with existing installations has shown how serious the effects of external noise on the intelligibility of received speech may be. This is particularly true when a conversation dealing with technical details is in progress, since the loss of a single word may destroy the value of a large proportion of an intercepted conversation.