U.S. airlines carry more passengers, use less fuel than a decade ago

Jet fuel use by U.S. airlines rose 3% in 2015 and 2% in 2016, but the usage last year was 11% lower than it was in 2006, according to the U.S. Energy Information Administration. And, 7% more passengers were flying on U.S airlines in 2016, than in 2007.

U.S. airlines with annual operating revenue of more than $20 million used 17.7 billion gallons of fuel in 2016, according to the U.S. Department of Transportation’s Bureau of Transportation Statistics.

While the number of flights has been declining annually, the number of airline passengers has risen 20% to 822 million in 2016, from 2007. Most of the passengers traveled on domestic flights. International flights accounted for 9% of flights by U.S. airlines, but “30% of available seat-miles, as international flights tend to use larger planes with more seats and travel longer distances,” according to the EIA.

Airlines increased the number of passengers while decreasing the number of flights by increasing their “load factors, which are measured as revenue-earning seat-miles as a percentage of available seat-miles,” according to the EIA. “Non-revenue seats include unoccupied seats as well as the travel of some passengers such as aircraft employees, air marshals or safety inspectors.” Load factors on domestic flights increased to 85% in 2016, from 80% in 2007. On international flights, they rose to 81%, from 80% over the same period.

Jet fuel use hasn’t risen has much as air travel because airline fuel economy has imprved. Average fuel economy has risen 22% to 63 available seat-miles per gallon in 2016, from 52 available seat-miles per gallon. Average fuel economy in terms of revenue seat-miles per gallon has risen 27% to 53 revenue seat-miles per gallon in 2016, from 41 revenue seat-miles per gallon in 2007. “The larger gain in fuel economy measured using the revenue seat-miles per gallon metric reflects the effect of increased load factors in reducing the amount of fuel needed to move paying passengers to their destinations,” according to the EIA.