by Michael Sivak, Sivak Applied Research

Because of the war in Ukraine, many international flights of various airlines are currently affected by the closed airspaces. Specifically, they are forced to take longer routes that avoid these airspaces, increasing the total fuel consumed. Moreover, some of them also need to reduce the number of passengers because they are now required to carry extra fuel and food, further increasing the fuel consumed per passenger.

A recent article by Jacopo Prisco has documented the impact that closed airspace over Russia has on a one specific flight—a Finnair nonstop flight from Helsinki to Tokyo (Narita), using an Airbus A350-900. In this brief post, I will use the values from that article to calculate the increase in the fuel consumed per passenger on this route.

The basic facts from the Prisco’s article are summarized in the table below. (Commenting on the sharply reduced maximum seats available now, Prisco indicated that the increased fuel consumption is “making the flights environmentally and financially challenging. For that reason Finnair is [now] prioritizing cargo, where demand is stronger.”)

The calculations made use of two ratios, each involving the two routes: the total fuel consumed (70/50 = 1.4), and the maximum passengers (330/50 = 6.6). When these two ratios are combined, the result is that (if fully occupied), the current route uses 9.2 times the fuel per passenger compared with the usual route (1.4 * 6.6 = 9.2). Thus, the current route has about 9.2 times the energy and environmental impacts per passenger than the usual route. (Obviously, these calculations do not take into account the increased cargo on the new route.)

Michael Sivak is the managing director of Sivak Applied Research and the former director of Sustainable Worldwide Transportation at the University of Michigan.