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In-flight Lightning Strike Damage
Assessment System
(ILDAS) |
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| Project Overview |
| Synopsis |
| ILDAS Partners |
| Project Organization |
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Synopsis Background Commercial passenger aircraft are on average struck by lightning once a year. The effects of lightning on aircraft and helicopters are minimal for low-amplitude strikes, but higher-amplitude strikes may result in expensive delays and important repair and maintenance. The present certification threat level is derived from cloud-to-ground lightning strike data measured on instrumented towers. While historically this threat definition has served the purpose of lightning protection adequately on metallic airframes, modern aircraft incorporate an increasing amount of composite materials that make them more susceptible to damage. Moreover, aircraft now employ more high-authority electronic control systems that are susceptible to upset and damage. As a result of the introduction of extra protection measures the advantages of modern materials could be cancelled by the addition of weight and higher cost. To be able to design appropriate lightning
protection, fixed-wing aircraft and helicopter manufacturers have
a strong need for a good definition of the threat that lightning
poses to aircraft.
The In-flight Lightning Strike Damage Assessment System ILDAS is a research project within the scope of Aeronautics Research of the 6th Framework Programme of the European Commission, which has started in October 2006 and will end in March 2009. The project is a joint effort of twelve European companies. The first objective of the ILDAS research project is to develop and validate a concept prototype of an ILDAS, capable of in-flight measurement of the properties of actual lightning strikes. Such a system gives better knowledge of the actual effects of a lightning strike to a fixed-wing aircraft or a helicopter, which can be used to improve aircraft design. Based on the actual measured properties of a lightning strike, the second objective is to enable the development of tailored and efficient maintenance inspection procedures which must be applied after a recorded strike. In order to achieve these high-level objectives, it is necessary to develop an innovative and efficient measurement system concept prototype for in-flight measurement of lightning strikes to aircraft. ILDAS uses advanced smart sensor techniques which enable characterization of lightning strike parameters and current flowing through the aircraft skin during an in-flight lightning strike. For the purpose of measured data interpretation, development and implementation of an innovative Inverse Method, based on a numerical simulation of the lightning current propagation, will be performed within the project. Finally a database concept will be defined dedicated to the measured and deduced lightning data, enabling subsequent exploitation. The development will primarily focus on Airbus
fixed-wings aircrafts. Adaptation to helicopters, which is of particular
interest given the use of composite materials on them, will come
at a later stage. In the limited time-frame of the project, the
system will be tested on a mock-up and also on an A320 but only
on-ground Project scope and further exploitation Regarding the lightning sensor subsystem a generic sensor will be developed able to measure the H-field. The sensor will be designed to be located on the top or bottom fuselage of an A320 type aircraft. Sensors required for other locations, like wings, horizontal stabilizers and vertical fin will be based on this design but not further specifically adapted for actual mounting. The generic sensor will be adapted to be located externally to the aforementioned locations for the sole purpose of performing the A320 ground test. Regarding future exploitation of the ILDAS results, two major phases are foreseen. The first phase will be further development of the ILDAS on-board subsystems dedicated to a specific aircraft on which ILDAS will be actually flown; possibly a prototype aircraft. In this phase sensors for other dedicated locations should be developed, along with specific required interfaces to the ILDAS. This "for-flight" ILDAS will also be subjected to certification effort, enabling the system to fly on a prototype aircraft. After successful in-flight verification of
the ILDAS, the second and final development phase could be defined.
This phase should start with an extensive business case study in
order to be sure that actual application to an operational fleet
will be overall cost effective. Further industrialization for serial
production and final certification are part of this final phase.
Description of Work At the start of the ILDAS project the inputs will be defined in terms of end-user needs and state-of-the art technology. The need for the measurement system will be further detailed with all stakeholders involved, defining the measurement requirements and in-flight lightning measurement sensor constraints. During this early study phase the need to protect aircraft and helicopters against the effects of lightning strikes and the cost of the protection measures will be taken into account. The state-of-the-art in lightning strike measurements, available sensor technologies and electro-magnetic modelling will be defined, as a starting point for innovation. During the development of the solution the needs will be transformed into requirements for a lightning strike measurement system prototype with on-board recording of the data. The technology development for the prototype of the measurement system will focus on innovative and reliable sensor technology, measurement chain and data recording technology development. There will be a strong interaction between the prototype development and the electro-magnetic analysis research in order to further define the related measurement data recording chain, the analysis and the management of the lightning data, and other data collected during the lightning events.
The ILDAS research project will yield a complete system concept that has been verified during simulated on-ground lightning tests. The project will also yield the validation of the inverse method for deriving the strike amplitude and attachment points on fixed wing aircraft and on helicopters. After future industrialisation and final certification, the actual application of ILDAS in aircraft and helicopters enables a rapid build-up of the lightning database contents. Better knowledge of lightning properties also enables European and other standards committees, which act on behalf of the European aircraft industry, to verify and possibly improve the lightning test standards. This should also enable optimisation of the protective measures of aircraft, through tailoring the design to the properties of real lightning, resulting in a reduction in the cost and weight penalty of protective measures. Improved knowledge of the actual lightning strike should lead to efficiency of maintenance operations after a recorded strike. This will strengthen the competitiveness of the industry by reducing aircraft delays and operating cost through a reduction in maintenance time and other direct operating costs.
Project coordinator organisation name:
Contact: EC Officer: Dr. Pablo Perez-Illana Partners
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