Headline:

Are Europe's air routes costing the earth? This study shows that the European air route structure leads to distances flown of up to 9% more than would be the case if aircraft could fly directly . In addition to its impact on the environment, the extra fuel burnt could be costing the airlines in the order of 1,000 to 2,500 million euros per year.

Executive Summary:

Flight efficiency and its impact on environment

Executive Summary

The European air traffic route structure is subject to regular changes in order to satisfy the differing needs of its users in terms of safety, capacity, and economy. However, route network optimisation criteria do not always sufficiently include environmental impact.

This study shows that the European air route structure leads to distances flown of up to 9% more than would be the case if aircraft could fly directly.

The planned routes of civil flights are verified and approved by Air Traffic Control (ATC), but the real route flown may be quite different from the planned one. A flight may be allowed to take a direct route, or obliged to take a longer route due to weather, dense traffic, military zones, and so on. These tactical ATC changes have an environmental impact; fuel burn on the upper atmosphere and, in the vicinity of airports, both fuel burn and noise.

The “Flight Efficiency and Impact on Environment” project has been set up to develop indicators that can be used to measure the impact of the Air Traffic Control system on the environment. These indicators allow the impact of changes to the Air Traffic Management (ATM) system to be observed over time in terms of distance, flight duration, fuel burn and costs to airlines and environment. They are used by the EUROCONTROL Performance Review Commission for its annual performance review of air traffic management in Europe.

The present report is the continuation of an activity, which started in 2000. At that time, the flight efficiency study was limited to selected flights in the Maastricht upper area control centre. In 2001 the study covered a wider area of Europe - Austria, Benelux, Italy, and UK.

The 2002 study of flight efficiency indicators are presented in this report. The geographic area has further been increased both geographically and in time to cover Benelux, Denmark, France, Germany, Ireland and UK. The data for the study were derived from the Enhanced Traffic Flow Management System (ETFMS) of the Central Flown Management Unit (CFMU).

According to the ATFM summary 2002 published by CFMU [Ref 4] there were on average 22567 flights per day in the EUROCONTROL boundaries (31 member states), corresponding to a daily average of distance of approximately 17,240,000km (31,000 flying hours per day).

The Route Efficiency, Duration and Total Fuel burn indicators were calculated on a sample of data comprising 10 days of 24 hours traffic in July and September 2002, averaging 27000 flights per day of which an average of 4000 were used for study (16%).

The analyses focus on domestic and Intra-European flights, i.e. flights starting and terminating within the geographic area covered by sample data. Flights that departed to or arrived from airports outside that area, as well as over-flights are not included. From approximately 27000 flights per day in the EUROCONTROL area, the study could make use of approximately 4000 flights per day.

The Route Efficiency results with the 2002 data sample indicate that real routes are on average 8.9% longer than the corresponding "Direct routes".

Duration, Fuel Burn and emission for each flight were analysed by the Advanced Emission Model (AEM) tool. Results show that real traffic consumes 9.6 % more fuel than the corresponding traffic flying direct trajectories. The Landing and Take-Off cycle (LTO) was not included in these calculations, as it is impossible for most aircraft in this phase of flight to go directly between the airport and the limit of the TMA. The approach procedure can be simplified, but not removed completely.

To complement the study on the issue of landing and take-off phases additional investigations were made for a Terminal Manoeuvring Area (TMA) scenario. The applicability of distance, noise and fuel consumption indicators for the LTO phases are discussed. The study relies on simulated data generated by the Total Airspace and Airport Modeller (TAAM). Indicators were measured by comparing “real” procedures with “most direct” procedures. However, focussing on a single TMA, the results are difficult to generalise. The ultimate purpose of applying indicators to a TMA would be to identify possible trade-offs between procedures to mitigate noise and fuel consumption. A future study should include a wider selection of airports.

Finally, an economic evaluation of the en-route flight efficiency indicators is presented, measuring the costs of flight efficiency in the European route network. Two categories of costs (internal and external) have been estimated. Internal costs of flight efficiency are defined as the amount of airline direct operating costs that could be avoided under the hypothesis of direct trajectories. External costs of flight efficiency are estimated to be the cost reduction of climate change impacts that could be obtained with direct trajectories. The latter cost estimation should be considered as a first approximate attempt to give a monetary value to negative externalities associated with flight inefficiencies. Considering the limited scientific understanding of some emissions (oxides of nitrogen, formation of condensation trails) and the economic debates on the valuation methods, the values we obtain should be considered as an order of magnitude which aim is to put flight efficiency performance in relative perspective among the other two main key performance areas which are ATM delay and capacity costs. These preliminary results indicate that the potential savings (the average of high and low bound hypotheses) which could be achieved if optimum profiles were feasible, compared to actual flight profiles reach € 1,764 million for airlines ‘internal costs’, and € 327 million for environmental “external” costs, which in total represent respectively 113% and 43 % of the annual European air traffic management delay and capacity costs.

It is acknowledged that improvements to the ATM flight efficiency cannot be made in isolation. Future studies in the context of Flight Efficiency will endeavour to take into account ATC system capacity and other ATM restrictions.

See the report... (will be available shortly)

For further information please contact Ian Fuller or Sylvie Chesneau (Flight efficiency indicators) or Jean-Claude Hustache (economic evaluation).