In systems for transmitting control motion there may be two shafts set in any relative position, each carrying a lever arm, and the ends of the lever arms may be connected by a link having ball ends. In general, the range of working movement for such a system is somewhat limited and the relationship between the angular movements of the two shafts is non-linear.

Although for some purposes it may suffice to mock-up the system and determine the motion experimentally, for other purposes analytical treatment may be required. The general solution given below is readily applied to particular cases, which may be simpler.

Late in 1947, at the instigation of the members of the Project Office of Short Brothers Ltd. of Rochester, an approach was made to the management of that Company on the subject of subsidised flying training for employees. Enthusiasm, unlike funds, was not lacking and the proposal was sympathetically received by the management, who agreed to make flight training to “A” licence standard available at one pound per hour, pre-1939 rates. The necessary apparel, including helmets and goggles, were supplied on loan, and training began at the Rochester Flying Club on Tiger Moth aircraft which were later supplemented by Magister and Auster types.

Air travel at 600 m.p.h. to 650 m.p.h. in the next decade and the use of multi-seat twin rotor helicopters on internal air routes to help to solve terminal delay problems, bring in their train growing problems of Air Traffic Control. Full use of high speed civil transports and helicopters does not seem practicable within the British Isles unless the problem of the siting of landing strips is reviewed and unless ideas on this subject are recast in the light of growing experience.

To the commercial airline pilot Great Britain is indeed a “tight little island.” It will appear smaller yet when the de Havilland Comet jet air liner operates to time-tables of approximately double the speed of most of the existing schedules of today.