Abstract :
Aircraft constructed largely from composite materials offer significant improvements in operating cost, passenger comfort and environmental impact. These new technologies have necessitated a review of the way aircraft are tested to ensure survivability against lightning strikes. The Society of Aerospace Engineers (SAE) prepares technical input to support the Radio Technical Commission for Aeronautics (RTCA) and the European Organisation for Civil Aviation Equipment (EUROCAE). In December 2007, the latest revision of RTCA DO160 was released. The EUROCAE equivalent document ED14 has also been issued.There has long been a discussion about incorporating aspects of the DO160 indirect lightning tests into the MIL-STD-461. This has now gained in importance and a task force are reviewing the necessary tests that could be incorporated into the military standard. For civilian aircraft DO160 and ED14 revision F provide a generic basis for testing that is used by equipment manufacturers as a basis for their own standards which are written for specific configurations. Both Boeing and Airbus have issued standards for their new aircraft types which take into account the quantity of composite material used in the aircraft structure and also the use of new technologies, such as electrical actuators, inflight entertainment (IFE), etc. DO160 section 22 sets out a widely accepted view of the test methods and immunity levels required for aircraft-mounted line replaceable units (LRU). These methods include recommendations for pin injection, Cable Induction (CI), and Ground Injection (GI) tests using waveforms designated 1 through 5. In the latest revision of DO160, use of the waveforms has been extended to allow application with both aluminium and composite aircraft structures. Changes introduced in the latest RTCA and EUROCAE standards are designed to keep pace with technology advances in the aerospace industry. Many military platforms use DO160 as the basis for their indirect lightning- or voltage spike testing requirements. This relationship is set to become much more concrete and will have significant influences in both the civilian and military sectors, particularly in relation to the acceptance of equipment for military applications under COTS (Commercial Off The Shelf) schemes.
