The title of this paper may be said to cover almost the whole field of the immediate endeavours of those who are concerned with the design and technical development of military aeroplanes, and especially of fighters. The term transonic is not precise, but may be defined conveniently as applying to those speeds of flight, in the region of the speed of sound, when all the customary aerodynamic design rules cease to operate. Theoretically, therefore, transonic flight consists entirely of problems.

In choosing a title for this paper, the words “ operational research ” might have been preferable to “ production research ” in the sense that “ operations ” refer to the strategic deployment of all the forces at the disposal of management, but to most engineers they would imply research into manufacturing processes only.

To judge by the newspapers, the day of the turbine powered transport aircraft is already here. This is not to say that the piston engine is no longer required; probably it will be in use for many years to come, particularly for small aircraft, but new major designs must certainly be planned so as to take advantage of this revolutionary new form of prime mover.