Although normal flapped and /or slatted wings may be considered as having a variation of camber because of the deflection of such devices, a variable camber airfoil is considered here as a mechanical unit employing flexible leading and/or trailing edges, thus eliminating surface discontinuities, but otherwise operated in the same manner as the more conventional devices they replace and is simply illustrated in Fig. 1 (i.e. flaps and ailerons on the trailing edge and slats or droop on the leading edge). The use of varicam trailing edge systems for lateral control implies that such systems should preferably be capable of both up and down (i.e. differential) movements.

In 1781-84 Carl Friedrich Meerwein (1737-1810), a South German builder and architect to his namesake, Karl Friedrich, Prince of Baden, worked on ideas for a practical ornithopter. Living in comparative obscurity in Emmendingen, a small town near Freiburg, he began in August 1781 by building a simple pair of ellipsoidal wings. He might have taken the matter no further had his interest not been caught by reports of Pierre Blanchard's abortive flying attempts in Paris, published in a Basel journal in July 1782. During the next two years, when everyone in Europe was talking about the French balloonists, Meerwein decided to set out his ideas for a heavier-than-air machine. Published in Basel in the summer of 1784, his book was widely read. A modified French version was published in the same year and reissued in 1785, and in 1812 a Portuguese translation appeared.

The scope of the subject is a challenging, if not a forbidding, one. It is to trace the evolution of routes, capacity, charters, designation and rates from Chicago to the present day. Collectively, these issues encompass the question of governmental regulation of the international air transport market and embrace the total air transport system. However, there is no attempt to catalogue the specific of these policy developments worldwide. Rather, it is attempted to analyse the foundations of international aviation policy, in a shorthand steeplechase through the past, present and into the future and, in this way, to offer some interpretations of the developments over the past thirty years. In so doing, it is hoped to place in perspective the complexity of the international system and the many interrelated factors which must be taken into account by those who bear the heavy responsibility of determining national policies.

The general theory and formulation of Part 1 can be applied to a whole family of element shapes. However, quadrilaterals and triangles which are compatible with each other are found to be most useful in idealising general structures. The lowest order polynomial shapes of this kind which are generally curved are the ‘biquadratic’ quadrilateral and the ‘quadratic’ triangle. These have nodes (or nodal pairs for the sandwich elements) situated at the corners and the mid-sides of the ‘parent’ elements. The quadrilateral therefore has eight nodal pairs.

Little information is available on the behaviour of the base pressure on a body of revolution having a following body in its wake. A preliminary investigation for the case of axisymmetric rear body has been reported by Mishra and Chatterjee. Their experiments were conducted on a 20° included-angle blunt cone. Mishra and Das reported an investigation for the case of asymmetric rear bodies having the same diameter. These investigations indicate significant rear body effects on the base pressure.

In multistage rockets, the flow characteristics of upper stages could be seriously affected by the proximity of a lower stage after they separate from one another.