Definition
A unit of frequency equal to one thousand cycles per second (1,000 Hz). In aviation, kHz is used to express the tuning frequency of low and medium frequency radio equipment, most commonly NDBs (non-directional beacons) and ADF receivers, which operate in the 190–535 kHz range.
Plain English
A way of measuring how fast a radio signal vibrates. One kHz means the signal cycles one thousand times every second. Pilots see kHz on the dials of older or low-frequency navigation radios.
Context Anchor
Seen in navigation and communication equipment discussions when radio frequencies are listed or tuned.
Derivation
From 'kilo-' (Greek 'chilioi', meaning thousand) and 'hertz' (named after German physicist Heinrich Hertz, who proved radio waves exist). So kilohertz literally means 'one thousand cycles per second.' Knowing this helps pilots see kHz and MHz as the same kind of measurement at different scales — kHz is thousands, MHz is millions.
Why Pilots Care
Pilots select and identify the correct radio frequencies for ATC and navigation by reading values in kHz.
Grounding Statement
A radio set to 350 kHz is tuned to receive a signal cycling 350,000 times each second.
Intuition Check
kHz is not a radio channel name by itself. It is the unit used to state a frequency.
Example Sentence 1
Example Sentence 2
Low-frequency navigation aids often operate between 200 and 500 kHz.