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FOR preliminary design work on transport airplanes, a graphical method is outlined for determining the effect which changes in a set of chosen major design variables will have on the airplane's ability to meet a given set of specifications and regulations. Engines, propellers, and wing geometry are selected. Then for each condition laid down as a specification or regulation, a limiting curve of maximum weight allowed by the condition is plotted as a function of wing area. These curves are developed from basic data and standard equations. If it is possible to meet all the conditions, the limiting curves - when plotted together on one graph - will enclose an area on the “allowable” side of all curves.

FLYING at altitude intensifies most problems, simplifies some, the author shows. Increasing operating altitude from 25,000 ft to well into the stratosphere lowers temperature more than 50 F, and reduces pressure to one-fifth the sea-level value. This complicates structural problems. It affects the hydraulic and control systems, electrical systems, cooling, and air conditioning, and increases the danger from failure of any of these essentials. Gusts and turbulence, on the other hand, are lessened by flying high. The author charts the extent of each of the problems, and shows how altitude economy gains make solutions imperative.

Because of the rapid growth of air travel, both cargo and passenger, the payload capacity required for future transport aircraft is too great to be accommodated by fuselages of conventional configuration (that is, single-deck, single-aisle, up to 6 seats abreast). Fuselage design philosophy was therefore re-evaluated in a recent Douglas study, and this paper reviews some of the features of that study. Factors affecting fuselage design are outlined and trends are discussed. It is concluded that the forthcoming wide, single-deck fuselage, seating up to 10 abreast, will have a potential capacity of about 550 passengers. For larger capacities, the greater efficiency of multi-deck fuselages over that of the single-deck becomes increasingly apparent on a per-passenger basis. The use of multi-deck fuselages, however, will raise new problems-particularly those of airport terminal design and passenger evacuation-but these should not prove insurmountable.

This paper explains the different applications of ground effect machines and why they should be built in aircraft manufacturing companies. The importance of L/D and initial cost is shown, and also the levels which have to be achieved in order to compete with ships. The main advantage of ground effect machines, the capability to move fast over water, and the potential market for such vehicles are pointed out. Assault operation is mentioned as well as operation over land, mostly swamps.