Tarja Kettunen & Jean-Claude Hustache, ISA Software, Paris, France
Ian Fuller, EUROCONTROL Experimental Centre, Bretigny, France
Dan Howell, James Bonn, CNA Corporation, Alexandria, VA
Dave Knorr, Federal Aviation Administration, Washington, DC

Abstract

The paper presents two similar studies carried out in the field of flight efficiency, one by the EUROCONTROL Experimental Centre, one by the FAA.

The studies calculate the excess distances of flights as the difference between the actual flight path length and the direct route length. The results of the EEC study suggest that aircraft fly around 10 percent excess distance compared to direct routes. In the US the inefficiency is around 6 to 8 percent. The cost of flight inefficiency is evaluated.

The important division of flight inefficiency between terminal and en route airspaces is explored. 70 percent of the total excess distance flown in the US is found to take place within terminal airspace and the remaining 30 percent in en route airspace. The European study supports this finding based on the results for certain airport pairs.

Differences between direct routes and wind optimal routes as well as the impact of weather in flight efficiency are also discussed.