How To Reduce Radio Interference in Aircraft?
During standard flight operations, pilots regularly use their radio equipment in order to establish and maintain communication with Air Traffic Control personnel and others for the means of safety. As radio interference can affect the quality and capability of communication, it is essential that engineers enact proper measures to suppress electromagnetic fields and electrostatic interference. While some interference may manifest as audible noises from communication systems, large static electricity discharges can present a hazard to sensitive components if they are unprotected. Across most aircraft, the most common methods of reducing radio interference include shielding, isolation, bonding, and static discharge wicks.
Methods Of Reducing Reducing Radio Interference in Aircraft
As electrical interference can stem from various components on the aircraft itself, it is important that avionics are well protected so that their performance and reliability is maintained. Rather than shield the sensitive components themselves, braided conductive shielding is implemented for ignition systems, AC power lines, switching devices, propeller control systems, voltage regulators, and rotating electrical devices which all can create damaging fields. With proper shielding implemented on such components, unwanted current is directed into the ground rather than being allowed to radiate. To further protection, electrical components should always be bonded to the airframe.
Another method that may be used to suppress unwanted radio frequency interference is isolation. To isolate an interference, the source of noise needs to be separated from the circuits of related equipment. Generally, the antenna lead-in wire serves as the most common source of the problem, and the fix may only be moving the component a few inches away. If shielding and isolation of the antenna lead-in wire is not sufficient, then a filter may be added to the input circuit.
As an aircraft operates and soars through the sky, static electricity can begin to build up in high amounts. To prevent the build-up and radiation of static electricity and charges that pose danger to sensitive components, bonding may be used. Variable resistance serves as a major risk for components, and bonding will connect metallic parts electrically to minimize the production of noise. Regardless of surrounding components, it is always highly recommended that one bonds every metal part of the aircraft and airframe in order to mitigate the build-up of electrical charges. Bonding connectors are very useful, and they often come in the form of bonding jumper and clamp parts. For the bonding jumper, such components should be very short and metal-to-metal contact should be established. If the bonding connector is only used for preventing radio interference, then its resistance value may be around 0.01 ohm.
One last common method of reducing radio receiver interference is to install static discharger wicks. As precipitation static builds up on an aircraft, corona discharges may be released in the form of short pulses of radio frequencies. With the use of a static discharger aircraft component, precipitation static can be discharged at a safe distance from the antennas of avionics. Often placed at the trailing edge of control surfaces, vertical stabilizer, and wing tips, such components may either be flexible or semi-flexible and are attached through fastening or epoxy. In order to ensure that all static discharger wicks are optimally secured onto the aircraft, connections should be regularly inspected.
Conclusion
With the implementation of shielding, isolation, bonding, and static discharger aircraft wicks, radio interference can be minimized for clear communication between pilots and air traffic control. At NSN Parts Now, we serve as a leading online distributor of aircraft parts with our expansive inventory of new, used, and obsolete items. With AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation, we ensure the highest quality parts through testing, inspection, cross-referencing, and much more. If you would like to receive a quote for items that you are most interested in, you may begin the process today through the submission of an Instant RFQ form..