Fairchild/Dornier C-26 Metroliner: NAV/COM & ELT Test Units

NAV/COM and ELT test units evaluate and verify the performance of an aircraft’s navigation, communication, and emergency locator systems. These testers simulate real-world signals to assess how onboard radios, antennas, and ELTs respond under operational conditions. Regular use of these devices helps ensure the aircraft’s safety systems are working properly and meet regulatory standards. By identifying faults before flight, they play a critical role in minimizing downtime and avoiding in-flight issues.

ELT (emergency locator transmitter) testing is essential to confirm that these life-saving devices will function properly in the event of a crash or forced landing. ELTs transmit distress signals that help search and rescue teams locate the aircraft quickly. Testing verifies battery condition, signal transmission, and antenna performance, all of which must meet strict regulatory requirements. Ensuring ELTs work as intended enhances safety and compliance for both general and commercial aviation operations.

NAV/COM and ELT systems should be tested during routine maintenance checks, avionics troubleshooting, or any time they are suspected of underperforming. ELTs must be tested annually to comply with FAA regulations under FAR 91.207. Additionally, NAV/COM systems are often checked during preflight readiness inspections or after any avionics upgrades. Using dedicated test units streamlines this process and ensures the accuracy of the results.

When selecting a NAV/COM test unit, look for features such as multi-frequency support, high signal accuracy, user-friendly interfaces, and rugged construction suitable for hangar or ramp environments. Some advanced units also include automated test sequences, built-in GPS simulation, and data logging capabilities. Compatibility with both analog and digital radios is also a key consideration, especially for modern fleets. Brands like Laversab and VIAVI offer reliable, field-tested solutions with these features.

Yes, many modern test sets are designed to handle multiple functions, including testing NAV/COM and ELT systems from a single device. These all-in-one testers help streamline workflow and reduce equipment costs by offering versatile testing capabilities in one compact unit. They're ideal for maintenance teams working on diverse aircraft platforms. This consolidation also reduces setup time and simplifies technician training.

In the U.S., ELT testing is governed by FAA regulation FAR 91.207, which mandates annual inspections to ensure signal transmission accuracy, battery condition, and antenna functionality. Similar regulations are enforced internationally by EASA and ICAO. Tests must confirm the ELT activates on impact and transmits a distress signal on approved frequencies. Proper documentation of these tests is required to maintain airworthiness and compliance.

NAV/COM test sets simulate signals that replicate real-world flight conditions, allowing technicians to verify that the aircraft’s radios and antennas respond appropriately. This helps detect weak transmissions, faulty receivers, or antenna misalignments before they become problems in flight. Preventing communication issues is critical for both air traffic coordination and emergency response. These testers ensure pilots can rely on clear, uninterrupted communication at all times.

Most NAV/COM and ELT test units are designed to support a wide range of aircraft, from general aviation to commercial airliners and even military platforms. However, compatibility may vary depending on the radio frequencies and avionics systems installed. It’s essential to choose a test unit that meets your aircraft's specific requirements and interfaces. PJi’s aviation specialists can help guide you to the right equipment based on your fleet profile.

VIAVI and Laversab are two of the most trusted names in avionics testing, known for producing high-accuracy, durable test equipment. Their NAV/COM and ELT testers are engineered for reliability, ease of use, and consistent performance under demanding conditions. Features like automated test sequences, intuitive interfaces, and compact form factors make them ideal for both hangar and ramp use. These manufacturers are widely used by MROs, airlines, and avionics shops around the world.