Preface: Background and objectives, Danish Environmental Protection Agency

1998 Fuel Use and Emissions for Danish IFR Flights

Preface: Background and objectives

During recent years more and more attention has been paid to various environmental impacts from aircraft emissions, especially when released into the atmosphere at upper-tropospheric and lower-stratospheric flying altitudes. The environmental effects are both related to global warming from greenhouse gases and perturbations in atmospheric ozone concentrations, which in turn affects the solar ultraviolet radiation balance. The effects become more important considering the present development in the air traffic sector and future expectations for air travel demands. The air traffic passenger kms travelled globally are projected to grow about 5% per year for the next 20 years to come. Even though future aircraft will become increasingly more fuel efficient, this cannot prevent a global fuel penalty of about 3% within the same time period (IPCC, 1999).

The environmental problems associated with air traffic can only be effectively addressed via international co-operation at many levels. One of the means is the establishment of emission conventions. Parties are obliged to bring down the emission budget according to agreed emission targets, and the submission of sectorial emission information in turn reveals the aircraft sector share of the total emissions. CORINAIR (COoRdination of Information on AIR emissions) is the European air emission inventory programme coordinated by the European Environment Agency for annual sector-wise national emission estimates. CORINAIR consists of inventory guidelines for each sub-sector and an emission database with an output format suited for reporting to both the United Nations Framework Convention on Climate Change (UNFCCC) and the United Nations Economic Commission for Europe (UNECE) conventions. For air traffic the UNECE transport expert panel assists the development of the inventory guidelines.

Until recently the CORINAIR methodology for aircraft emissions encompassed only guidelines for fairly detailed Landing and Take Off (LTO) and more rough cruise emission estimates (CORINAIR, 1996). Strong efforts have since been made by the UNECE transport expert panel to improve the CORINAIR methodology in terms of more updated and detailed information on fuel use and emissions (CORINAIR, 1999). Some of the expert panel members have also joined the ANCAT/EMCAL (Abatement of the Nuisances Caused by Air Transport/sub-group on EMission CALculation) working group formed under ECAC (European Civil Aviation Conference). The gathering of experts from many European institutes involved with simulation models and inventory work has made it possible to feed new information on fuel use and emissions into the CORINAIR methodology in areas where previously few or no data were available. Another spin-off expected from this work is that a recommendation will be dealt with by ANCAT probably later this year encouraging ECAC member states to use the new CORINAIR methodology calculating national aircraft emission estimates.

The largest improvement of the CORINAIR methodology is the inclusion of fuel use and emission data per distance flown. On the other hand this detailed data makes the actual calculation procedure more difficult and time consuming to perform. Information on air traffic statistics is needed on a pr flight level and much effort is needed to group all aircraft into representative types.

The objectives of this project are 1) to make an operational procedure for calculating aircraft emissions according to the new CORINAIR guidelines, 2) on the basis of this to recommend changes in national emission estimations and 3) to develop a tool for assessing fuel use and emissions for individual flights. The objectives will be met by establishing an emission inventory for IFR (Instrumental Flight Rules) jet and turbo-prop flights from Danish airports in 1998. Due to a lack of data emission estimations will not be made for helicopter operations, military flights and piston-engined aircraft movements.

Key tasks are to gather flight data and information on aviation codes for airports and countries. From this a proper categorisation can be made of all flights from Denmark in 1998 by origin and destination airports and their representative aircraft types. Another important part is to obtain consistent information on fuel use and emissions for representative aircraft types. Sufficient grouping of flights and the availability of corresponding fuel use and emission data facilitates the calculation procedure. Final results will be fuel use and emission estimates for domestic and international LTO and cruise.

Chapter 1 gives an overview of the environmental effects from aviation. In chapter 2 international conventions are described related to emissions from air traffic. The current CORINAIR model version for aircraft inventories is documented in chapter 3. The new version of the model is explained in chapter 4 in terms of input, the calculation procedure and the computed results. A comparison with current CORINAIR results, findings from international inventories and special simulations for Danish domestic flights will be made in chapter 5. The final chapter outlines the conclusions of the present project.

The project was funded by the Danish Environmental Protection Agency (DEPA). The steering group consisted of Hugo Lyse Nielsen and Miloslav Zakora, both DEPA, Nic Michelsen, Danish Civil Aviation Administration (CAA-DK) and Morten Winther, National Environmental Research Institute (NERI).

In this project acknowledgements should be made to Bruno Nicolas, Eurocontrol, and Johnny Funder, CAA-DK, for supplying information on flight data and ICAO aviation codes translations, respectively. Also many thanks to Monika Kudrna and Manfred Kalivoda, Psia-consult, to Robert Falk, DTI and to Anders Hasselrot and Jan Westerberg, FFA, for providing fuel use and emission data for the calculation part. Kristin Rypdal, Statistics Norway, and Reidar Grundström, Swedish Civil Aviation Agency, should also be thanked for their co-operation to implement Swedish emission data into the CORINAIR databank. Thanks are also given to Peter Schøn and Lars Henrik Olesen from Copenhagen Airport for providing information on aircraft type classifications. Thanks to Rikke Næraa, Danish Railways, for providing data on energy consumption on trains and to Anne Mette Jørgensen, DMI, for reviewing the text on environmental effects.