Monthly Discussion



Airplanes, Aviation Technologies, and Our Need to Travel


Much talked about recent events such as the Concord crash, the Farnborough air show, and the Airbus super jumbo (A3XX) call for a big-picture update of related issues previously discussed in Predictions and Conquering Uncertainty.

To begin with, I want to remind the reader of some insights revealed by using S-curves and the concept of Darwinian competition in social and market activities. For example, when a large S-shaped curve was decomposed into smaller ones, see Exhibit 3 below.



Exhibit 3.  An overall S-shaped pattern decomposed into constituent S-shaped curves according to a rigorous procedure. The horizontal axis represents time. At the bottom of the figure we see the life cycles corresponding to the constituent S-curves.


S-curves are nested like Russian dolls. Consequently, one finds many products in a product family, many product families in a company, many companies in an industry, and many industries in the global economy. In all cases, the growth process follows the same S-shaped pattern but the time frames are different, and the corresponding life cycles have different duration. Life cycles are longer during the high-growth period of the overall curve and shorter during the low-growth periods in the beginning and at the end, as sketched in the bottom of Exhibit 3.

          An example of nested S-curves can be found in the aviation industry. Wide-body aircraft can be seen as a family with about a dozen members, each having its own life cycle. Early members, such as the DC10 and Lockheed Tristar, were shorter lived than the Boeing 747. On the other hand, the recent rapid appearance of the 767, a number of Airbuses, MD11, and 777 implies that these aircraft will have shorter life cycles than the 747. As in the pattern of Exhibit 3, the wide-body family of aircraft underwent successively the stages of: two short life cycles, one long, and again a number of short ones. We can thus conclude that the overall S-curve, describing the growth process of the wide-body family, is approaching a ceiling, with the 747 as the central long-lived product. In the future, we should expect little—if any—growth in the annual passenger-mile totals of wide-body aircraft. In fact, the average size of airliners on transatlantic flights has already shown signs of decline. In that light, the super-jumbo underway by Airbus, the A3XX, has a doubtful market. This aircraft will have to steal market share from the high-capacity aircrafts in use, and even then, its sales would never reach the hundreds of units anticipated by Airbus managers.

          But let us zoom back and look at all of jet aviation as one family with two as yet members. The first one—early jets—underwent a 15-year long growth process. The second one—wide bodies—underwent a 30-year long growth process. Since the life cycles of the constituent S-curves are increasing, the picture suggests that we are still before the mid point of the overall curve and that there should be a new upcoming type of aircraft with an even longer life cycle.* What should this type of aircraft look like?

          Communities grow around their transport systems. According to a traveling innvariant discussed in Predictions, people are happiest when they are on the move for an average of about 70 minutes per day. If it takes more than seventy minutes to get from one point to another, the two points should not reasonably belong to the same "town.” Cars permitted towns to expand. When people only traveled on foot, at three miles per hour, towns consisted of villages not much larger than three miles in diameter.

          There was a factor of ten in speed between foot and car transport, but also between car and airplane transport, taking the average airplane speed as around 300 miles per hour. Airplanes expanded the limits of urban areas further and it is possible today to work in one city and live in another. Air shuttle services have effectively transformed pairs or groups of cities in the United States, Europe and

Japan into large "towns."

          If we now imagine the supersonic airplane of the future with an additional factor of ten in speed, say an average of 3,000 miles per hour, we can visualize the whole Western world as one town. In his book Megatrends , John Naisbitt claims that Marshall McLuhan's "world village" was realized when communication satellites linked the world together informationally. This is not quite accurate. Information exchange is a necessary but not a sufficient condition. It is true that empires in antiquity broke up when they grew so large that it took more than two weeks to transmit a message from one end to the other. But it is also true that communications media are poor substitutes for personal contact. The condition for a "world village" is that it should take not much more than one hour to physically reach any location.

          Expanding in space as far as possible is of primordial importance for all species. It is what reproducing unicellular amoebas are after, as well as what the conquest of the West and space explorations were all about. According to this reasoning supersonic travel and the realization of "world village" become inevitable. But there are constraints. Productivity can not be compromised. As with the standard of living, decrease is not an option for a new way of life. The productivity of a new-technology aircraft (i.e., the product speed times payload) must increase. This was not the case with the Concord whose productivity significantly fell short of the productivity of the Boeing 747 introduced around the same time. The Concord's payload was too small. It should be able to carry around 250 passengers to match the productivity of wide-body aircraft. And even with 100 passengers the time the Concord gained flying, it lost refueling. This explains its commercial failure.

          Other insights revealed by S-curves are found in Exhibit 4 depicting the beginning of chaos. By casting the analytical mathematical expression of the S-curve into a discrete formulation, we observe chaotic fluctuations appearing at both ends of the growth process. In Exhibit 4 we see the onset of chaos, for a certain combination of the parameters values. At this point, chaos is not fully installed yet, but there is an important oscillation both in the beginning and at the S-curve. In real-life situations we cannot see the early oscillation completely because negative values have no physical meaning. We see, however, a precursor followed by an accelerated growth rate, an overshoot of the ceiling, and finally erratic fluctuations. These features correspond to real phenomena. Accelerated growth is a catching-up effect, usually attributed to pent-up demand. The overshoot is a typical introduction into the steady state. As for the precursor, it is often considered a fiasco, unfairly so.


Exhibit 4.  One of the first patterns obtained by putting an S-shaped curve in a discrete mathematical form. The deviations from the familiar S-curve demonstrate the early catching-up effect, the precursor, and the overshoot.


          According to our earlier discussion, the Airbus A3XX corresponds to the "overshoot" of the growth process of the wide-body family of aircraft. As for the Concord, it corresponds to the "precursor" of the next family of aircraft, the supersonic family. Sticking to Exhibit 4 we can say that after the Concord there will be no supersonic commercial travel for a while (a duration comparable to the life time of the Concord, i.e., 30 years). But then supersonic travel will take off and will grow at an accelerated rate (pent-up demand). From the discussion around Exhibit 3 we can surmise that this new family of supersonic aircraft will have a life cycle longer than thirty years, and will constitute the central long-lived family of aircraft in jet aviation.

To do this successfully, supersonic aircraft technology will have to rely on a richer fuel, such as liquid natural gas or liquid hydrogen (see last month's discussion topic). This fuel will permit high productivity, namely, supersonic speeds as well as relatively high carrying capacity, but probably narrow fuselage (single corridor). Last but not least, the hydrogen fuel will do marvels for the environment. Let us leave aside, for the time being, the fact that the most realistic way of producing and liquefying hydrogen in such quantities today is via nuclear energy!


* There is independent corroboration of the fact that the overall aviation curve is not yet half way completed (see Predictions page 178). There is a huge number of air routes still to be established.