Eco-Design for Airframes - Technology streams
Four main technical areas of progress are addressed to cover all the phases of the aircraft lifecycle.
These areas will be considered for significant parts of the aircraft: structure, cabin covering and furniture, vehicle systems components/equipment, engine components, electronics.
After the initial evaluation of current technologies, a set of requirements for future technologies is established. These requirements are used to select (“green”) technologies to be investigated in the frame of a development maturation phase. The most promising technologies are then evaluated and further matured through a life cycle demonstration. The TRL of the technology candidates are generally estimated at 3. The technologies will be matured individually in order to reach a TRL 5 before going to demonstration. The demonstration itself will allow reaching TRL 6.
A final eco-statement is conducted after extrapolation to real industrial conditions to evaluate the environmental impact of newly developed technologies and to benchmark them against current technologies evaluated at the beginning of the project, thus providing inputs to the Technology Evaluator.
The activity is conducted for the production, maintenance and withdrawal phases of the aircraft lifecycle ("on-ground lifecycle").
More than seventy technologies related to the fields material & surface treatments and manufacturing processes are addressed which are organised in 11 clusters listed below.
A. Low energy curing
B. Light alloys / Green metallics
C. Composites for high temperatures
D. Green polyurethane foams for seating
E. Thermoplastic composites for interior applications
F. Thermoplastic A/C structures
G. Electrostatic Functionality of organic materials
H. Aerospace alloys, processes, surface treatments and coatings suitable for reducing lifecycle environmental impact
I. Biocomposites for cabin interior applications
J. Materials for electronics
K. Magnesium alloys
The ecological impact of materials along the entire life cycle is considered. This includes especially:
- Raw materials extraction and refining (renewable materials when possible and reasonable); materials processing companies will have to be involved in the project to work on this specific item;
The most relevant materials are selected, at first in terms of environmental impact, chemical and physical properties (corrosion resistance, fatigue, fretting wear-out...) and secondly taking into account weight and costs. Obviously, these materials will have to be as effective as current ones.
The new manufacturing processes, aiming to the "Green aircraft Production Factory", are optimised to reduce energy consumption and pollution while keeping low cost objectives. The general industrial requirements of the future clean processes can be summarised as follows:
- Optimisation of the work flow and of transport of aircraft components,
- Highly integrated processes,
- Low energy, low VOC, dry and clean processes,
- Recyclability of ancillary manufacturing and integration tools,
- Concepts of "One shot process" or "reduced steps process" (Direct Manufacturing, Sol-Gel, E-coating ...),
- Hazardous materials elimination (e.g. chlorinated solvents).
Around thirty technologies are being developed in the field of "Long Life Structure" aiming of increasing the lifetime of the structure based on sound diagnostic and prognostic methods. Improved testing methods are addressed to ensure a cost and time efficient derivation of accurate and comprehensive data bases to support this long life objective. In addition, green repair solutions further guarantee safe and "ecolonomic" long term use of the aircraft structure.
Finally, the "End of Life" area is addressed through around fifteen technologies, which will provide a route for EoL aircrafts with an optimal environmental impact (especially regarding resources use, air/water/soil pollution, etc.) in a competitive environment. For the aircraft EoL phase, a structured waste management approach is chosen to identify, and then recover or recycle all materials and components in the most environmentally sound way, given they do not have to be disposed of due to hazardous properties.
The new technologies are evaluated and monitored through system level activities: the eco-statement mainly based on Life Cycle Analysis (LCA), producing the life-cycle assessment. The LCA of a product is based on the representation of the aircraft life through a succession of unit steps at all level of the aircraft integration, from individual pieces up to the aircraft. Examples of such steps are machining, drilling of mechanical parts, assembly, painting, dismantling, etc. The LCA tools produce for each step the quantified environmental impacts by using a LCA database on processes and then the environmental impact results at each level of the product tree, up to the complete aircraft.
LCA tools already exist today and are used by other sectors such as automotive, railway and maritime industry. Synergy with aeronautic is taken into consideration for the use of those tools and the development of a general LCA methodology. The databases used are specific to the industry sectors and a major objective of Clean Sky through the Eco-Design ITD is to build up such database for the aeronautic sector for the generation of LCA results for aircraft and helicopter.
As presently implemented, the general eco-statement logic is based on the definition of a limited number of typical aircraft parts to cover all technologies and processes encountered on aircraft. LCA are first performed on parts based on current technology and then are performed on the same parts but based on new Clean Sky technologies. Comparison of results will produce an evaluation of benefits brought by the new technologies to be matured at TRL 6 through on ground demonstrations. LCA results on parts will then be extrapolated to evaluate life cycle environmental impacts at level of the overall aircraft.
As already anticipated, the on-ground demonstration will address among others low energy curing, light alloys/green metallic, thermoplastic aircraft structure, bio and thermoplastic composite for interiors, material for electronics and composites for high temperature applications; covering the on-ground aircraft life cycle from material development to recycling.