The development of North Atlantic navigation and flight planning procedures in RAF Ferry Command

Phil Steele's precis of Dries Bulstra's paper on flight planning prompts me to recall flight planning procedures on the North and South Atlantic in the days of RAF Ferry Command. The sparsity of radio-navigation aids, coupled with few weather reports and even fewer diversion airfields made flight planning and en-route navigation an interesting challenge. RAF Ferry Command rose to the challenge, aided by volunteer captains from American civilian airlines. The catalyst for this success lay in decisions taken in 1935.