The Aviation Radio: Common Problems, Proven Fixesby John Persinos | September 18, 2018

Communication between pilots and ground crew involves more than speaking. The MRO field must now contend with a broad array of new technologies, all of which introduce malfunction and noise.

The perception of how well the aviation radio works is affected by the amount of unwanted noise and interference pilots must listen to while using the radios. This article explains some of the sources of unwanted noise, as well as the proven techniques by which savvy aircraft radio technicians fix noise and interference.

The pilot plays an integral part in solving these problems by providing detailed documentation about the failure, such as when, where, and how it occurred.

With the advent of ultra-modern radios, such Garmin aviation radios, Yaesu aviation radios, and Collins aviation radios, noise levels have actually increased because radios are now more sensitive.

With further engineering improvements, the aviation radio has become quieter, but the problem is still there and much of it will remain until the aircraft’s environment changes.

The older the plane, the greater the potential for airplane radio noise haunting the corridors within the wiring and equipment. Paradoxically, as aircraft communication systems have gotten more sophisticated, they’ve gotten potentially noisier.

Richard Aboulafia, vice president of analysis with the Teal Group, aviation consultants in Fairfax, Virginia, points out that new radios are more prone to malfunction and mysterious noise contamination. “Technological change usually isn’t painless,” he says. “Radios are becoming interconnected with the Internet of Things and other advancements, which increases the odds of things going wrong.”

As the airplane radio becomes more sensitive, it has led to an increase in noise because the radios are able to hone in on the previously undetected noise as well as the weak radio signal.

This is amplified and is heard as noise in the headsets and speakers. All squawks should be closely investigated to duplicate the problem. The aircraft radio technician should adequately document what happened prior to the squawk developing. This is accomplished when the technician (or avionics manager) and customer first go over the pilot squawks.

Remember this well: noise is the harbinger of failure. Knowing about some of the potential noise sources is a giant step in preventing unwanted signals from entering the circuitry of aircraft communication systems.

Solutions are usually hindered by a lack of adequate information. The MRO troubleshooter must be fully familiar with the normal operation of the affected aircraft radio. Communication with the pilot about the failure or noise onset is a good start.

Aircraft Radio Troubleshooting

Here are four common problems with aircraft radio communication and how MRO experts can successfully address them. These pointers are based on what’s now occurring in the field:

1) Noisy reception.

Check for an antenna problem. Also, it could simply be a weak or noisy received signal.

2) Distorted or garbled reception.

Check speaker first, then airplane radio, audio amplifier, and associated wiring. If the audio panel uses push-button switches, they could be the problem.

3) Intermittent reception.

This phenomenon can be caused by the radio’s power wire, grounds, defective pins on the radio’s mating connector, problems with the aircraft radio itself, or damaged wiring from recent upholstery work.

Check to see if the COMM radio has an intermittent or defective microphone being keyed. This would kill all audio if the microphone key button is depressed. Many airplane radio technicians test for intermittent audio by turning on the ADF radio and listening to it while proceeding with other tests.

If the intermittent audio reception problem occurs, the tech will immediately hear the failure when the ADF audio quits. From there, the MRO technician should be able to isolate the problem further.

4) Weak transmission.

This could be from a bad microphone, radio or antenna, or wire breakage.