What is the Airframe ITD and what are the challenges?
The Airframe ITD is all about re-thinking and developing the technologies as building blocks and the “solution space”. This principle applies to the level of the entire aircraft, pushing aerodynamics across new frontiers, combining and integrating new materials, new manufacturing methods and structural techniques – and integrating innovative new controls and propulsion architectures with the airframe. Together with this, the Airframe ITD focuses on optimising these elements in respect of the challenges of weight, cost, life-cycle impact and durability.
The Airframe ITD scope will in some cases lead to totally new shapes in the sky; at this level of ambition, making significant strides forward into a new era of aviation for the middle of this century.
But what exactly is an airframe?
It's the main structure of an aircraft, comprising fuselage, wings, nacelles and empennage - the elements that physically support and protect all of the "vital organs" such as the engines, fuel systems, passenger cabin, as well as the flight deck - and carries its payload: passengers and cargo.
In fact, the perennial challenge in aviation is to reduce aircraft weight and improve aerodynamic efficiency – goals that can be achieved through improved airframe design. An additional and important challenge is to do so while reducing the design and build times, hence reducing the cost of the aircraft. By reducing airframe weight, it's possible to reduce operating costs, fly more efficiently and reduce fuel-burn and emissions by virtue of carrying a lighter load.
Traditionally, airframes have been made out of metals – mostly aluminium, steel and/or titanium alloys, but these are being superseded in many cases by carbon composite and other composite materials. About half the weight of the airframes of the latest airliners is made up from composite material, bringing weight saving, and better resilience to the fatigue and corrosion issues associated with metals. But many challenges lie ahead in further optimising aircraft structures to make full use of the potential that new materials, manufacturing processes and design capabilities can unlock in the search for better performance at lower cost and lower life-cycle impact.
For that reason, to rise to the challenge, airframe demonstrators are planned for Clean Sky 2's Airframe ITD using novel composite as well as hybrid materials and structures across a variety of different airframe types and sizes – for wings, fuselage, and control surfaces as well as in areas of engine integration.
The challenge, however, goes far beyond the structural aspects of the airframe. New techniques will free up constraints and allow designers to create more aerodynamically efficient shapes and build aircraft in configurations that would not be feasible with current technologies. Alongside the innovative aircraft architecture, new ways of designing will be possible inside the passenger cabin, such as new approaches to integrating systems into the airframe. In short, the Airframe ITD is about step-changes, radical thinking, and integration of the major elements. Thinking on a big scale, but getting the details right too.
The Airframe ITD addresses a complex set of challenges and has been split into 10 major Technology Streams (TS):
Innovative Aircraft Architecture
The aim of this Technology Stream is to investigate some radical transformations of the aircraft architecture and demonstrate the viability of some of the most promising advanced aircraft concepts. This will be done by identifying the key potential showstoppers and exploring relevant solutions, elaborating candidate concepts, and assessing their potential.
Noise Shielding, Embedded engines, Innovative Overall Configurations
This Technology Stream is designed to make further progress on drag reduction which will be applied to major drag contributors, especially the nacelles and wings. This Technology Stream aims to increase the Nacelle and Wing Efficiencies by means of Extended Laminarity technologies.
High Speed Airframe
The High Speed Technology Stream will focus on the fuselage and wing, enabling better aircraft performance and quality of delivered mobility services. The aim is to reduce fuel consumption without compromising the overall aircraft capabilities (such as low speed capabilities and versatility).
This will introduce innovative control systems and strategies to make gains in overall aircraft efficiency. New challenges that could bring step-change gains do not lie in the optimisation of the flight control system component performing its duty of controlling the flight, but in opening the perspective of the flight control system as a system contributing to the global aircraft architecture optimisation. It could contribute to sizing requirement alleviations thanks to smart control of the flight dynamics.
Novel Travel Experience
This Technology Stream will investigate new cabin concepts including layout and passenger-oriented equipment and systems as a key enabler of product differentiation, having an immediate and direct physical impact on the traveler, with potential in terms of weight saving and eco-compliance.
Next Generation Optimised Wing
The Next Generation Optimised Wing Technology Stream will lead to progress in the aero-efficiency and to better, more durable, affordable and lighter-weight wing structures through the design, build and ground testing of innovative wing structures. The challenge is to develop and demonstrate new wing concepts (including architecture) that will bring significant performance improvements (in drag and weight) while improving affordability and enforcing stringent environmental constraints.
Optimised High Lift Configurations
This Technology Stream will progress the aero-efficiency of wing, engine mounting and nacelle integration for aircraft that serve local airports, thanks to excellent field performance. This will be beneficial particularly in rural and regional aviation, helping towards Europe‘s 4-hour door to door aspirations.
Advanced Integrated Structures
The Advanced Integrated Structure Technology Stream will optimise the integration of systems in the airframe along with the validation of important structural advances, thereby boosting production efficiency and manufacture of aircraft structures.
Advanced Fuselage to introduce innovation in fuselage shapes and structures
This Technology Stream will include cockpit and cabins, with new concepts of fuselage to be introduced to support future aircraft and rotorcraft. More radical aero structural optimisations are intended to lead to further improvements in drag and weight reduction in the context of growing cost and environmental pressure, including the emergence of new competitors.
This Technology Stream focuses around Eco-Design activities embedded in the Airframe ITD. These are mainly concentrated around developing environmentally sound technologies, and on performing LCA activities to quantify the benefit brought by the newly developed technologies. The Eco-Design Thematic Areas target the environmental benefits of lower impacts during the production of aircraft parts, their maintenance phase, as well as the aircraft‘s end of life phase.
Due to the comprehensive scope of technologies undertaken by the Airframe ITD, addressing the full range of aeronautical portfolio (Large Passenger Aircraft, Regional Aircraft, Rotorcraft, Business Jet and Small Transport Aircraft) and the diversity of technology paths and application objectives, technological developments and demonstrations for Clean Sky 2 are structured around 3 major Activity Lines.
- Demonstration of airframe technologies focused around High Performance and Energy Efficiency (HPE)
- Demonstration of airframe technologies focused around High Versatility and Cost Efficiency (HVC)
- Demonstration of airframe technologies focused around Eco-Design (ECO)
Tomorrow’s challenge, today’s call to action
The world needs more aircraft – by the mid-2030s it will need at least twice as many as are currently flying. But tomorrow's planes need new technologies to keep pace with ever more stringent ecological requirements and to meet passenger needs in terms of the aircraft cabin environment and the cost of air travel.
Conventional airframes are reaching the limits of efficiency. Radical new directions have to be taken to bring about the dramatic weight and emissions reductions - and meet overall sustainability targets - that are needed to comply with ACARE and Flightpath 2050 Goals.
Strength comes from daring to be different, and the exploratory nature of the technology streams to be pursued under Clean Sky 2's Airframe ITD strategically spreads that dare across a wide variety of potential applications in wing, fuselage and empennage science.
The way that aircraft are made will need to change, and the Airframe ITD is at the heart of that transition. If Europe takes the lead in innovative airframe design it will enhance its leadership position in the aeronautical market for decades to come.
The Clean Sky 2 initiative, in developing new airframe technologies, has "first mover advantage". It's an unmissable opportunity to take a strategic lead in shaping the products that will transport us, and tomorrow's populations, efficiently, comfortably, safely and reliably - and with the utmost respect for the environment.