Definition
A unit of frequency equal to one million cycles per second, used to describe the radio frequencies on which aviation communication and navigation equipment operate.
Plain English
A way of measuring how fast a radio signal vibrates. One megahertz means the signal completes one million waves every second. Aviation radios are tuned to specific megahertz numbers so the right station is heard.
Context Anchor
Seen in radio frequency listings, avionics manuals, airport information, and FAA material that describes communication or navigation frequencies.
Derivation
From the Greek 'mega' meaning 'large' (used in science to mean one million) and 'hertz', named after the German physicist Heinrich Hertz, who first proved radio waves exist. Knowing 'mega = million' helps explain why one megahertz equals one million cycles per second.
Why Pilots Care
Pilots must tune their radios to the correct megahertz frequency to talk to the right controller, receive weather, or use a navigation aid. A wrong frequency means no contact and no guidance.
Intuition Check
Do not read this as a place, channel name, or station name. Megahertz is the unit used to measure the frequency that the radio is tuned to.
Example Sentence 1
The tower frequency at this airport is 118.3 megahertz.