In view of the book references being cited I thought that forumites might be interested to note that the main text that I sent through to the BBC’s David McKenna came from the family of Errol Galbraith Knox:

“The Official History of Australia in the War of 1914-1918
Volume VIII, ‘The Australian Flying Corps’ by FM Cutlack (Angus and Robertson, Sydney, first published 1923). Appendix No 5, pp 430-433, features an account of the system of training pilots of the Australian squadrons in England, in the first eight months of 1917, described by Errol Galbraith Knox.”