What is currently the most common communication system used in aviation?

The most common communication system used in aviation is the VHF (Very High Frequency) system. This is because VHF offers several advantages that make it particularly suitable for aircraft communications. VHF frequencies, typically in the range of 118 to 137 MHz, are ideal for line-of-sight communication, which is critical for the needs of both commercial and general aviation. This frequency range provides clear audio quality and is less susceptible to interference compared to lower frequencies, which is essential for maintaining effective communication between pilots and air traffic control.

Furthermore, VHF radios have a wider coverage area for aviation purposes, allowing for reliable communication in the majority of flight operations, including during takeoff, landing, and cruise phases. It is also the standard frequency for air traffic control communication around airports and in controlled airspace, making it the primary choice for daily operations.

While other frequency systems like HF and UHF have their specific uses in aviation—such as HF for long-range communications and UHF for military applications—VHF remains the predominant system due to its effectiveness, reliability, and the existing infrastructure supporting it in aviation environments.