What is the primary frequency for aircraft control?

• A. 320.75 MHz
• B. 235.7 MHz
• C. 235.7 kHz
• D. 235.7 GHz

Answer: (B)

Aircraft control communications rely on radio frequencies in specific bands, with military air control typically using the UHF range for reliable, line‑of‑sight voice links. The frequency 235.7 MHz sits squarely in that UHF band and is commonly designated as the primary control channel in doctrine and training. It’s the standard choice used to coordinate with aircraft, offering the right balance of range and clarity for air‑to‑ground control.

The other options miss the mark for practical control communications: 235.7 kHz is far too low for voice aviation communications and is used for longwave purposes, not ATC. 235.7 GHz is in the terahertz range and not used for aviation radio links due to hardware and propagation limitations. 320.75 MHz is in the same broad band but isn’t the designation typically assigned as the primary control frequency in the standard references.