Note D — Chapter I · THE SIGNAL CORPS AVIATION SCHOOL AT SAN DIEGO

“It is estimated that the average cost to France of training each pilot is five thousand dollars ... no less than from four to six months are devoted to the training of finished pilots. Although I have just come from France, the progress of aviation is so rapid that much of my own knowledge may be out of date before I again return to the front.”—C. D. Winslow, “With the French Flying Corps,” 1917, 4–5: N. Y.