Search Results

The advances in electronics and software since two decades have increased the use of digital technology in modern aircraft. Because digital electronics are powered with low level energy and are made of miniatured components, they are very sensitive to electromagnetic energy. It takes a single glitch to change the entire information. Therefore, insuring the proper protection of critical systems against Electromagnetic energy is a must during early design phase of the modern aircraft. All the onboard systems that govern aircraft functions are interconnected by hundreds of meters of wires and bundles. Moreover, the immunity of any signal on board aircraft is for at least 50% guaranteed by the cable shielding effectiveness and the shield termination. Wiring acts like an antenna: it can either radiate or collect energy. If not protected, it may pick up any electromagnetic noise in the surrounding; consequently, unwanted energy can modulate signals and cause system malfunction.

During an aircraft flight, water droplets, snow or precipitation will impact the fuselage and the wing surfaces, and develop static charges on the structure. Because of composite materials, those charging particles can produce potential differences between surfaces of different aircraft zones. The transients generated by the discharge can couple into onboard electronic/electrical systems and cause no found faults or upsets. Electrostatic Discharge (ESD) phenomenon resulting from corona effect can generate very high electric field that can couple with wiring bundles and generate communications disruption during flight. ESD effects have to be properly addressed during an aircraft design, as are Lightning and HIRF. This paper presents some theoretical considerations and experimental data based on full aircraft ESD ground tests at Bombardier facilities in Mirabel (Montreal).