Very Large Aircraft

It is not at all certain that the supersonic Concorde will be followed by fleets of new supersonic cruise civil transports. However, the prospect of subsonic commercial jet transports larger and heavier than the Boeing 747-400 is almost a certainty, with some Airbus A380 superjumbo jets already on order. Thus, it is reasonable to review the expected stability and control problems for very large airplanes.

23.1 The Effect of Higher Wing Loadings

Higher wing loadings than on airplanes of the Boeing 747-400 and advanced 777 classes seem inevitable for commercial airplanes of the 1,000-seat category, if these air­planes are to fit into current airport terminals, runways, taxiways, and maintenance facilities that have had reasonable modifications. Folding wings, tandem main wings, or some other radical departures from current technology would get around the necessity of higher wing loadings, but radical innovations are unlikely in airplanes that will be as expensive as super­jumbo jets. All-wing superjumbo jets have been studied by several groups, but the Boeing and Airbus designs for superjumbo jets show quite conventional arrangements.

Some of the stability and control consequences of using high wing loadings in very large airplanes can be predicted. Higher wing loadings than current practice imply higher fuel weights relative to the aerodynamic forces generated by the wings and stabilizing surfaces. Dynamic fuel slosh effects, a nonproblem for 747-class airplanes, will require a fresh analytical look.