Aircraft EMC

High-intensity radiated fields (HIRF) and indirect effect of lightning (IEL) have the potential to be catastrophic for aircraft. A thorough understanding of HIRF and IEL from the design phase to the certification phase is key to preventing issues and guaranteeing a safe flight.

Download this white paper to learn about using a digital twin to design and certify increasingly electrified aircraft for HIRF and IEL compliance.

HIRF and lightning certification with a digital twin

Aeronautical platforms are operating in an increasingly complex and more severe electromagnetic environment. There are more external and internal radiating sources than ever before, including: higher power levels of wanted and unwanted emissions, extensive use of materials with reduced shielding effectiveness and electronic devices replacing mechanical and hydraulic flight controls. These electrical and electronic devices that perform safety-critical functions may be damaged by a lightning strike (IEL) or radiation (HIRF) as well as by general electromagnetic compatibility (EMC) issues. Using a digital twin allows full aircraft EMC analysis to be front-loaded in the design process, meaning critical design decisions can be made much earlier to ensure aircraft program execution excellence.

Aircraft lightning protection

Aircraft electrification gives rise to new requirements for electromagnetic compatibility. As aircraft become more electrified, there is a corresponding increase in design complexity and required levels of integration. In addition to impacting program cost and time-to-market, this also introduces greater safety challenges.

When a lightning flash strikes an aircraft, the conduction of the electrical currents can have both direct and indirect effects. Direct effects of lightning (DEL) refer to the physical damage to materials caused by thermal effects, spark and magnetic forces. Indirect effects of lightning refer to electromagnetic interference in electrical or electronic equipment, with a special interest about equipment that belongs to systems or subsystems that perform critical safety functions. Using a digital twin in the aircraft development process allows you to ensure IEF certification for lightning protection.

How can aircraft be protected against HIRF?

HIRF immunity is the ability of the aircraft systems and equipment to correctly perform their functions in the presence of any electromagnetic environment generated from external radio frequency sources such as radio or radar emitters.

HIRF certification is designed to demonstrate that equipment and systems performing safety-critical functions can withstand the internal electromagnetic environment induced by a given external electromagnetic environment. Certification authorities have recognized numerical analysis as an option to support IEL and HIRF compliance.

HIRF and lightning compliance: How to design and certify increasingly electrified aircraft

To design and certify increasingly electrified aircraft, engineers need to implement robust, efficient processes for high-fidelity EMC analysis to deal with IEL and HIRF and ensure that aircraft achieve certification and guarantee passenger safety. To reduce expensive and time-consuming testing, aeronautical manufacturers are moving more toward a numerical modeling approach, using simulation to create a digital twin that allows them to address these issues before physical prototypes are built.

It’s important to understand the critical components as early as possible in the design cycle. These are classified as emitters (devices that emit electromagnetic noise through conduction or radiation), transfer paths (structures such as the electrical wire harness or fuselage that transmit electromagnetic noise throughout the entire system) or receptors (avionics systems, radar systems or sensors that are susceptible to electromagnetic interference). By identifying potential problems early in the design phase, engineers can make better decisions sooner that will enable aircraft to meet regulations and ensure passenger safety.

Read the white paper to explore the details.