n Part 1, we discussed some of the sources of and the historical basis for HIRF testing. With the increased use of “Fly by wire” controls of aircraft, the high intensity of radio frequency transmitters caused interference with these controls, at times with very serious effects. Test levels had to be increased, and methodology changed for components and subsystems, as well as complete systems and the full aircraft. RTCA’s DO-160B, which was in effect until 1989, had as its highest radiated susceptibility level ‘Category Z,’ which was 1 V/m from 35 MHz to 1215 MHz, with a bump to 2 V/m from 118-136 MHz. The lowest level in DO-160C (December 1989) would be 5 V/m, with a new maximum of 200 V/m up to 18 GHz.¹

In 1988, the SAE “was requested to develop guidance for designers’ aircraft, aircraft engine, and electronics components on how to maximize protection of airborne avionics and electronic systems from the adverse effects of high energy RF fields through which aircraft may fly.”² The SAE would create three groups, or Panels, to address the subject. Panel 1 would validate the HIRF environment. Panel 2 would support the FAA by writing the high-level advisory material for their rule making effort. Panel 3 would write the recommended practices to meet the environments they would identify. This work was focused on environments found in the Continental U.S. and its territories. A similar effort was underway in Europe through EUROCAE with Working Group 33, members of which participated in SAE’s AE4R HIRF Subcommittee. To assure uniformity and completeness, the Electromagnetic Effects Harmonization Working Group, or EEHWG, would assemble the data and information generated by the groups involved.

ompliance engineering is a field that demands meticulous attention to detail, a proactive mindset, and a deep understanding of regulatory landscapes. In this practical engineering article, we explore some of the lesser-discussed aspects of compliance engineering—those “odds and ends” that can make a significant difference in ensuring products meet stringent standards and regulations.

ome requirements are set in stone. But many of them need to be tailored for your specific hardware. If you apply standards blindly, you’ll run into all kinds of schedule-delaying problems: test methods and setups that don’t make sense, test failures that aren’t important and need to be waived, and missing problems that will pop up later during integration and checkout. Some standards, such as MIL-STD-464 and MIL‑STD-461, are explicit that they must be tailored. When a standard needs to be so general that it can cover everything from a walkie‑talkie to an aircraft carrier, you need to make sure that you’re applying it in a way that makes sense for‑your hardware.

So, when you’re sitting down to tailor your program requirements down to a specific set of hardware to be tested, where should you start? Here are some suggestions.

1. The document itself. It’s worth the time to sit down and read, in detail, as much of the original text as possible. It may have a table showing which requirements apply to different applications (such as Table V of MIL-STD-461 Rev G). There may be notes or footnotes that mention exceptions or specific configuration types to include or avoid.

he Dunning–Kruger effect¹ explains how overestimating one’s technical reach can narrow ESD evaluations to the decades‑old floor resistance-to-ground (Rtg) test—an essential metric since the 1950s, yet blind to system interactions. Three case studies show that skipping resistance tests of mobile technical elements (casters, chairs, carts) that depend on the floor as a series path to ground leads to false confidence and missed risks.

This article advocates pilot floor installations plus insitu body voltage, probability analysis of charge generation data, and mobileelement resistance tests to validate system-level performance and secure long-term staticrisk mitigation.

dvanced system on a chip (SoC) components use multi-die package technologies where single silicon chips are assembled on top of each other, beside each other on a larger interposer, or by combining various 3D packaging methods together. Connections between chips are formed by utilizing multiple technologies such as flip chips, substrates, interposers, silicon bridges, bond wires, micro bumps, and through-silicon-vias (TSV).

A single SoC can have hundreds to thousands of external connections between a component package and a printed circuit board (PCB). These connections require certain robustness against external electrical stress and can often tolerate electrostatic discharge (ESD) withstand voltages of more than 250 V charged board model (CDM) and 500 V human body model (HBM) during qualification tests. Each of these on-chip protection structures requires surface area from the silicon, but due to a limited number of connections, this is still feasible.

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s a continuation of our article Preparing for the EU’s New RED Cybersecurity Requirements from the June issue of In Compliance Magazine, this article will concentrate on the EN 18031-X series that was harmonized and published in the Official Journal of the European Union in January 2025, after our previous article was written.

Since our previous article covered the Radio Equipment Directive (Directive 2014/53/EU, known as the RED), plus other acts and directives referring to cybersecurity and why cybersecurity rules are necessary, we will not repeat them in this article.

The EN 18031-X series of standards was developed to provide manufacturers of radio equipment with a harmonized framework to meet the European Union’s (EU’s) cybersecurity requirements that became mandatory on August 1, 2025.

his is the first part of the fourth installment in a series devoted to the topic of shielding to prevent electromagnetic wave radiation. The first article [1] discussed reflection and transmission of uniform plane waves at a normal boundary. The second article, [2], addressed normal incidence of a uniform plane wave on a solid conducting shield with no apertures. The third article, [3], presented the exact solution for shielding effectiveness of a solid conducting shield. In this article, two approximate, yet accurate, solutions are obtained from the exact solution.