Electrical Flight Control Surface actuation is the key element of the "All/More Electric Aircraft" concept. It is widely recognized that the integration of all the aircraft secondary power systems, electrical, hydraulic and pneumatic, into a single type electrical system will provide significant weight and cost savings, better overall energy efficiency and improved reliability and maintainability figures because the reduction in the number of system components. In recent years various programmes have focused on the demonstration of the feasibility of the concept and in the analysis of fundamental problems related with the electric actuator technology, some of them still open today. These programmes, in Europe, have been based on real actuator specifications and requirements derived from existing AIRBUS aircraft. However, there are families of aircraft such as the very large airplane (500seats or more) or small regional transports (40-80 seats) for which this technology has never been explored. Recent and ongoing studies show that it is precisely for these aircraft types where substantial benefits can be gained from the "All Electric Concept", but those studies also indicate that new system/actuators architectures are required due to great differences existing in the sizing factors.
The proposed programme will focus its activities on the following main items:
a) Analysis of system/actuator architectures for very large and small transport aircraft where direct transfer of existing technology is not possible due to the big difference in power requirements;
b) Investigation into the overall integration of electrically powered actuators into the aircraft. No studies up to now have thoroughly addressed the integration problems of such actuators in terms of control surface flutter, reliability, redundancy, fault tolerance, fault isolation and performances after failures;
c) Specific studies to address basic actuator technology problems that still at present prevent the use of electrical actuators into new projects. These problems are, pump design, thermal dissipation, jamming avoidance in mechanical transmissions, robust actuator control algorithms, efficient failure detection techniques and the high cost of power electronic components;
d) Evaluation and development of more efficient key components such as electric motors, power switching devices, hydraulic pumps and mechanical transmissions. In order to achieve the above objectives in the most rationale and effective way two separate sub-projects have been defined targeted at specific objectives. Cross feeding of results between the two sub-projects will cover the gap that may other wise appear were these sub-projects be run independently.
The two sub-projects are:
1. Electric actuation package for very large commercial aircraft;
2. Active-standby electromechanical actuator development for regional airplanes (inclusive of flight testing). The successful completion of this programme will subsequently allow specific product development programmes to be undertaken by the participating companies, leading to the incorporation of this technology in the next aircraft generation. BE97-4419
Funding SchemeCSC - Cost-sharing contracts
88161 Lindenberg - Allgäu
B90 4LA Shirley
95056 Cergy - Pontoise