Environmental impact of disruptions and airspace inefficiencies in Europe

Airlines for Europe (A4E) commissioned SEO to estimate the climate impacts of disruptions and  inefficiencies in the European airspace over the 2015-2017 period. With respect to disruptions, we analysed the impacts of industrial actions (strikes) and technical failures at European Air Navigation Service Providers (ANSPs).

Results

Over the past decade, the fuel efficiency of flights within the European Economic Area (EEA) improved by 1.9% per year as a result of investments in new aircraft technology and more efficient operations. Over the 2015-2017 period, this resulted in a fuel saving of 3.9 Mt (Megatonnes) and a reduction in CO2-emissions of 12.2 Mt. This corresponds to the fuel consumption and emissions of around 1 million commercial passenger flights within the EEA.

Industrial actions and technical failures at ANSPs temporarily reduce the airspace capacity. This might lead to the rerouting of flights which increases flight distance. Over the 2015-2017 period the total flight distance of intra-EEA flights increased by 4.6 kilometres due to industrial actions and technical failures at ANSPs. This required an additional 13.7 kt (kilotonnes) of fuel and caused 43.0 kt of extra CO2-emissions. This corresponds to the fuel burn and emissions of around 3,500 commercial passenger flights within the EEA. Industrial actions were responsible for the majority of the (95%) increases in flight distance, fuel consumption and emissions. Especially industrial actions in France had a large impact. This is explained by (1) the relatively large number of industrial actions that took place in France over the 2015-2017 period and the relatively long duration of these actions, (2) the fact that relatively much flights are affected by a French action due to the central location of France in Europe and (3) the fact that not all overflights are accommodated during an industrial action in France.

In addition, the European Air Traffic Management (ATM) system still leads to inefficiencies. Flights within the EER therefore were 0.61-0.76% longer than necessary. Over the 2015-2017 period the inefficiencies led to 229 kt of additional fuel burn and 721 kt of additional CO2.

Methodology

The development in fuel efficiency was estimated for each scheduled intra-EEA flight based on OAG Traffic Analyser data. Fuel efficiency was defined as: fuel consumption per revenue passengerkilometer (RPK). For each flight we calculated the fuel burn using the SEO emissions model. Passengerkilometers were calculated based on seatkilometers and average load factors.

The impacts of industrial actions and technical failures at ANSPs on flight efficiency were estimated using the econometric ‘difference-in-difference’ (DiD) method. First we made an inventory of all the disruptions that took place between 2015 and 2017 based on Eurocontrol data. Secondly, we analysed which airspace sectors were affected by these disruptions using Eurocontrol DDR/NEST data. Thirdly, we identified which flights would cross these sectors on an undisrupted day. Fourth, we assessed the change in horizontal flight distance of these flight on the day of the disruption using the DiD methodology controlling for possible time trends. Finally, we estimated to what extent the change in flight distance resulted in a change in fuel consumption and CO2-emissions using our emissions model.

The remaining inefficiencies in the European ATM system were based on performance indicators published by the Performance Review Body of SES. Based on these indicators we calculated to what extent these inefficiencies had increased flight distance. This increase was translated into additional fuel consumption and CO2-emissions using the SEO emissions model.