This paper describes the analysis of the experimental test results obtained during the low level swept coupling (LLSC) and low level direct drive (LLDD) tests on FALCON 7X horizontal tail plane provided by EADS-CASA. These techniques are evaluated during the aircraft high intensity radiated field (HIRF) certification process and in the scope of European Community's FP7 HIRF SE project. The analysis of low level test results shall be performed to estimate the influence of the test setup with particular regard to the in-flight coupling configuration. For this reason, finite difference time domain (FDTD) 3D computations have been used to determine the relationship between free field external radiation and skin current in different illumination angles and polarizations. Finally, after validation by comparison of the measured and computed skin current, measured bundle current are related to measured skin currents, to provide the transfer function link to the external field.Keywords-electromagnetic compatibility (EMC); aircraft; low level swept current (LLSC); low level direct drive (LLDD); high intensity radiated field (HIRF); finite difference time domain (FDTD); validation; skin currents; coaxial return.

This paper discusses the influence of simplifications in models used in the design of electromagnetic protection against indirect effects of lightning strikes. A real and complex test case such as the power plant of an A400M aircraft, simulated with the FDTD method, is chosen for this. The parameters studied are the inclusion/removal of installations, modification of electrical contacts, material properties, and changes in the cable characteristics. The simulations performed allow us to quantify the impact of different simplification approaches and, in consequence, to draw conclusions on the relative importance of different model features, being the most important ones to maintain the electrical contacts, to include installations and cables carrying high currents, to consider different materials, to respect the accurate cable routes or to take care of isolated equipment.

Radiated emission tests are generally performed in either free space, reflection-free environments, such as an open area test site or semi-or full-anechoic chambers, or in reverberation chambers. This paper describes measurements in semireflecting environments such as an office, a workshop of a large industrial apparatus or installation. The objective is to develop test methods and associated correction factors and uncertainties for measurements which are performed on-site, near large industrial apparatus which cannot be moved to an EMC laboratory. The measurement technique is based on reverberation chambers and tools such as insertion loss, quality factor, as well as a goodness of fit test were used to perform the test site analysis. The advantages and drawbacks of on-site measurements of large apparatus are discussed. A simplified, but not limited to perfect reverberation chambers, method of finding the measurement uncertainties was used to calculate the errors associated with imperfect reverberation and field uniformity, as well as the influence of noise and equipment nonlinearities. The results are given in form of a guideline, concluding that such measurements are possible.

Preparing the 3D-geometry models to perform electromagnetic compatibility (EMC) numerical simulations can be tedious and time consuming. Furthermore, the need to include the test setup in the models, in order to validate the software, by comparing the numerical results with the measured data, may lead to unwieldy simulation models with often unaffordable computational costs. In this paper, we illustrate a procedure to optimize and simplify the modeling process, together with guidelines for achieving the most unfavorable case in the simulation of EMC problems, as required for a certification process. A test case from the European FP7 HIRF-SE (High-Intensity Radiated Field Synthetic Environment) project is analyzed in this paper as an example of how to identify the unnecessary elements for the simulation, while retaining the essential physics of the problem.

Open area test sites (OATS) have been traditionally employed for aircraft electromagnetic compatibility certification tests because of the large size of these items. In this regard, unmanned aerial vehicles (UAVs) have emerged in the last years and, albeit being sometimes notably smaller, yet they have to accomplish for the same certification process. This paper investigates into the possibility of using a reverberation chamber for performing two aircraft low-level coupling tests, namely, low-level direct drive and low-level swept fields, and compares the results with those obtained in an OATS, in both cases using a representative part of a UAV. Index Terms-Aircraft electromagnetic compatibility (EMC) certification, low-level direct drive (LLDD), low-level swept fields (LLSF), open area test sites (OATS), reverberation chambers.