fly under the radar
To go unnoticed, especially for a long period of time.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He tries to fly under the radar at work.”
“Small mistakes often fly under the radar if nobody checks the final report.”
“The company kept its new project secret to fly under the radar until the official launch.”
“The quiet student managed to fly under the radar for the whole semester because he never raised his hand or caused any trouble in class.”
“By maintaining a modest lifestyle and avoiding public attention, the author managed to fly under the radar for decades while writing her best-selling novels.”
From military contexts of the mid-20th century, the phrase describes the manoeuvre of a pilot flying an aircraft at a sufficiently low altitude to escape detection by radar pulses. The curvature of the earth and the presence of terrestrial obstructions create a zone near the ground where a signal cannot penetrate, a physical limitation that allowed for unobserved movement. The idiom transitioned from technical aviation parlance into general English to denote any action taken to avoid notice.
- 01
drop off the radar
To vanish or fall into obscurity; to become forgotten or ignored.
- 02
fly blind
To do by guesswork; to feel one's way.
- 03
fly by
To pass or go past quickly, often without much interaction
- 04
fly by the seat of one's pants
To pilot an aircraft without the aid of instruments and without a flight plan, using only instinct, visual observation, and practical judgment.
- 05
fly in the face of
To act in a manner highly contrary to; to counteract or contradict.
- 06
fly in the ointment
Something (especially a minor thing) which ruins or spoils everything else, or makes it less pleasant; a nuisance or problem; a disagreeable or unpleasant detail.
- 07
fly low
To have one's fly (zipper) undone.
- 08
fly off
To flee rapidly; to run away.
Last updated August 10, 2026