The impact of an aircraft on the environment is generally considered as directly linked to its intensity of operation. A more global and accurate approach to evaluate this impact must take also into consideration the total aircraft life cycle.
The product life cycle can be split within three distinctive phases: aircraft design & production, aircraft use & maintenance, aircraft withdrawal. For each phase, there is a need to limit the quantity of natural resources (material, energy, water...), to use harmless materials and find non-polluting substitutes and finally to design an aircraft in a global perspective that addresses its dismantling and recycling.
The result from the life cycle assessment of the metro in Oslo should be considered to understand the meaning of the development of an industrial product with an environmental perspective. Looking at the overall life cycle impact on green-house effect (quantified in ton of CO2 equivalent) of the metro train, one can see the expected dominance of the phases:
On this example close to aircraft, the most critical phase regarding greenhouse effect is the product use, mainly due to the energy consumption. However, it is very important to note that the other phases are not negligible at all.
Compared with other industries such as automotive, the aeronautic industry is late in considering the global life cycle design approach but it is now necessary to spend significant efforts to prepare the future:
- The air transport impact on environment can be considered as being small compared to the automotive impact but it is continuously growing;
- Aeronautics is quite a young industry and the issue of the aircraft withdrawal is really emerging today.
The figure below shows an estimation of the withdrawal figures from the worldwide Boeing and Airbus fleet. Starting at about 2015, a steep increase of decommissioned aircraft is to be expected. An operational approach taking into account both the economic and the ecological aspects of available withdrawal will have to be available then if not before.
The global objective of the Eco-Design ITD is to reduce the product environmental impact while keeping competitiveness of the aeronautic industry. Eco-Design will address green design and production, maintenance, withdrawal, and recycling of aircraft. The optimal use of raw materials and energies, avoidance of hazardous materials, and the reduction of non-renewable energy consumption of systems on board will help to considerably reduce the environmental impact of the aircraft and its systems.
The Eco-Design ITD is focused:
- On one hand on designing equipped airframe with a minimum of inputs (raw materials, energy, water,...), outputs and nuisances (energy/warming, liquid effluents, gaseous effluents, solid waste, ...) all along the life cycle;
- And, on the other hand, to design architectures of aircraft systems, towards the more/all electrical aircraft, with the objective of reducing use of non-renewable and/or noxious substances (i.e. suppression of conventional hydraulic fluids) during operations and maintenance, while keeping the aircraft at the appropriate level of quality and performance.
The Eco-Design ITD (ED-ITD) gathers and structures from one side activities concerned specifically with development of new material and process technologies and demonstration on airframe and rotorcraft related parts stressing the ecolonomic aspects of such new technologies; from the other side, activities related to the All Electrical Aircraft concept related to small aircraft.
ED-ITD is directly focused on the last ACARE goal: "To make substantial progress in reducing the environmental impact of the manufacture, maintenance and disposal of aircraft and related products".
Reduction of environmental impacts during out of operation phases of the aircraft lifecycle can be estimated to around 20 % reduction of the total amount of the CO2 emitted by all the processes (direct emissions and indirect emissions i.e. produced when producing the energy) and 15 % of the total amount of the energy used by all the processes. In addition, expected benefit brought by the All Electric Aircraft concept to be highlighted through the conceptual aircraft defined in the vehicle ITDs is estimated to around 2% fuel consumption reduction due to mass benefits and better energy management.
The status of the global fleet in the year 2000 constitutes the baseline against which achievements will be assessed. Progress toward these goals will result not only from ED internal activities but also from the collaboration with the relevant cross-cutting activities in GRA , GRC, SFWA (business jet platform) and SGO (electrical systems).