Next level stuff: Affordable Flight Control System
Regional aircraft, because of their shortrange missions, spend much of their flight changing altitude. Clean Sky’s Affordable Flight Control System for a Multi-Mission Aircraft project aims to optimise the system capabilities and efficiencies for regional aircraft, bringing competitive advantage to European Aviation.
”The main objective of the Affordable Flight Control System for a Multi-Mission Aircraft project is to show technology maturity of integration of complex structures and systems in a regional aircraft configuration” says Luis Benítez, Clean Sky 2 Technical Manager at the RD Chief Engineering Office of Airbus Defence and Space. ”The flight control systems of regional aircraft are the whole set of sensors, actuators and computers which take care of the aircraft while flying. The intelligence that we can implement in such a system with the improvements in the aerodynamic shapes in wings and fuselage and the improvements in engine performances are crucial in future aircraft design. The environmental impact of the regional aircraft can be strongly improved with the aim of these technologies” adds Benitez.
There are three distinct but interrelated aspects to the project, focusing around the flight control systems, as Ruud Den Boer, Project Officer at Clean Sky explains: ”The first part is just flying the aircraft, the second part is load control alleviation and the third aspect in the flight control system is to shape the wing in relation to the situation of the aircraft”.
”The opportunity for the regional aircraft is that the morphing of the wing and the aerodynamic shape of the wing could be controlled by the flight control system, so you have the primary flight controls for the pitch, yaw and roll manoeuvre inputs – but then additionally you have load control alleviation, so that when you fly through a gust you have active control of the loads because, for instance, when you fly fast through a gust it gives a very high load in the bending moment of the wing. And that’s an important design parameter. The idea is that – and this is something you have for instance in fighter aircraft – when you fly through a gust you have a very rapid motion of, for instance, your ailerons to alleviate the loads. By reducing the high peak in the loads, you could design your wing much lighter. Currently during take-off and landing you have another configuration because the flaps are down but you could also have a more adaptive wing with a more adaptive shape aerodynamically, and then you could change the geometry of the wing during flight”.
For regional aircraft, all of this presents the potential to be operationally beneficial, because with short regional flights a lot of time is spent either ascending or descending, unlike long-haul where aircraft remain at a high and mainly constant altitude. So to optimise the short-range flight profile, the more that flight control systems can alter the shape of the wing to respond to the required conditions, changes in altitude, and alleviate loading, the more efficiently the aircraft will fly, making substantial savings in fuel possible.
In terms of demonstrations in the pipeline for this project, Airbus’s Benitez notes that ”in Airbus Defence and Space, demonstration of research and technology is a key factor where all our efforts can be shown and measured. In fact we have proposed several major demonstrators, the first ones on the ground where structures and systems are fully stressed to their limits, and finally in flight where technologies are tested by our test crews”.
To take this forward, plans are underway to use one of Airbus Defence and Space’s C-295 prototype aircraft says Benitez: ”We will install the results of many projects of Airbus Defence and Space and our partners in Clean Sky 2. It’s great to finally mount the efforts of many colleagues from all Europe in one of our aircraft. It is also important to remark the positive impact on the aeronautics from a global perspective because we can work with many partners from academia, research centres and other companies under the same umbrella of cooperation”.
”Right now, Airbus Defence and Space is at a point where results of basic research are becoming ’real’. Thus, first prototypes are under construction and we expect to start test activities at full scale size in the near future. Some achievements that we have today on our tables are for instance results in wind tunnel, new material properties with higher strength capacities and very low weight and new computers for aircraft control using more electrical paradigms” says Benitez, to which Clean Sky’s Den Boer adds that ”as for technology readiness levels in this project, items such as the aileron and spoilers and winglet actuation will be tested up to TRL6”.
Looking ahead, technologies developed in the Affordable Flight Control System for a Multi-Mission Aircraft project ”will contribute to improve European aviation, and from an environmental level” says Benitez, who also remarks that the project aims ”to improve on the one hand the impact of aviation on the environment by substantial decreases of CO2 and NOx emissions, and on the other the reduction of the noise footprint of the aircraft in take-off and approach phases”.
All of which is key, not only to improving passenger comfort onboard the aircraft, but also for being a ’better neighbour’ to those who live and work in and around airports and underneath the flight paths of regional aircraft – both in Europe and beyond.