A jet airliner's takeoff weight is over 50% fuel.
Robert Gorden inThe Rise and Fall of American Growth:
surprisingly, the period of most rapid decline in the real price of air travel occurred before the first flight of a jet plane. As shown in figure 11–10, the price of air travel relative to other goods and services declined rapidly from 1940 to 1960, declined at a slower rate from 1960 to 1980, and has experienced no decline at all in its relative price between 1980 and 2014. The growth rate of passenger miles traveled has mirrored the rate of change of the relative price except with the opposite sign, because lower prices stimulate the demand for any good or service.
The accompanying figure shows not merely a modest rise, but a sharp spike in airline pirces in 1979.
Among Gordon's economic specialisations is the aviation industry.