Researchers at Sensis’s Seagull Technology Center in Campbell, Calif., have calculated what they call excess fuel burned during taxiing at 13 of the nation’s largest airports. In this case, excess means the amount of time spent taxiing versus the ideal time required to proceed from the ramp to the takeoff point, and from exiting the runway to the ramp after landing, and then converting the time difference into fuel burn. Researchers found that at those 13 airports, $409 million in fuel (a rolling average, using fuel prices at the time the research was conducted) was consumed annually in surface movements, with no benefit to operators.

Researchers obtained the data by tracking every aircraft, large or small, moving on the airport surface with the Sensis ASDE-X, which combines advanced surveillance radar with a network of transponder multilateration stations. Analysts then matched this data to ATC tower records and other information sources to create a precise inventory of aircraft types, engines, fuel burn, taxi routes taken and speeds, single-engine taxi technique and a wealth of other inputs. Traffic variations throughout the day and other variables were factored in to develop the “ideal” taxi times at each of the 13 airports versus those achieved.

What does this mean to real-world operators? Is it just an interesting statistic from an abstract research project launched out of scientific curiosity? To the contrary, it was derived from part of the Seagull Center’s airport studies with NASA and is directly linked with the FAA’s NextGen future air traffic management program. Seagull researchers have worked with NASA to develop 60 high-fidelity airport models to support NextGen planners, whose aims include identifying ways of optimizing surface movements and airport layouts to speed surface flow.

The airports in the study are used predominantly by the airlines, so how relevant are the results to corporate operators? Relevant indeed, as whatever reduces the excess fuel burn of their airline counterparts reduces their fuel burn as well.

Before the application of new technologies such as ASDE-X, actual versus “ideal” taxi times could only be suspected, but never measured. Now, these studies will go a long way to ensuring enhanced surface movement efficiency for all users.