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” on the level of the entire or holistic aircraft: pushing aerodynamics across new frontiers, combining and integrating new materials and structural techniques – and integrating innovative new controls and propulsion architectures with the airframe; and optimizing this against 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, significant strides into a new era of aviation for the middle of this century will already be made.
But what exactly is an airframe?
It's the main structure of an aircraft, comprising fuselage, wings, nacelles and empennage - that physically supports and protects 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airframes have been made out of metals – mostly aluminium, steel and/or titanium alloys, but these are being superseded in many cases by carbon composite and other composite materials.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 optimizing 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 shapes and configurations that would not be feasible with current technologies. And 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 in to 9 major Technology Streams:
Innovative Aircraft Architecture, to investigate some radical transformations of the aircraft architecture.
The aim of this Technology Stream is to demonstrate the viability of some of the most promising advanced aircraft concepts (identifying the key potential showstoppers and exploring relevant solutions, elaborating candidate concepts) and assessing their potential.
This is a key technological path to make further progress on drag reduction, to 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
This will focus on the fuselage and wing, enabling better aircraft performance and quality of the delivered mobility service, with reduced fuel consumption with no compromise on overall aircraft capabilities (such as low speed abilities 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 architecture optimization. It could contribute to sizing requirement alleviations thanks to smart control of the flight dynamics.
Novel Travel Experience
This will investigate new cabins including layout and passenger-oriented equipment and systems as a key enabler of product differentiation, having an immediate and direct physical impact on the traveller, and with potential in terms of weight saving and eco-compliance.
Next Generation Optimized Wing
This 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.
Optimized High Lift Configurations
This will progress the aero-efficiency of wing, engine mounting and nacelle integration for aircraft that serve local airports thanks to excellent field performance.
Advanced Integrated Structures
This will optimize the integration of systems in the airframe along with the validation of important structural advances, and to make progress on the production efficiency and manufacturing of structures.
Advanced Fuselage to introduce innovation in fuselage shapes and structures
This will include cockpit and cabins. New concepts of fuselage are to be introduced to support future aircraft and rotorcraft. More radical aero structural optimizations can lead to further improvements in drag and weight in the context of growing cost and environmental pressure, including the emergence of new competitors.
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 2 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 (HVE).
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 evermore stringent ecological requirements and to meet passenger needs in terms of the aircraft cabin environment and the cost of air travel.
Conventional airframes have just about reached 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 nine 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.