Definition
An ATC instruction directing the pilot to switch the transponder to the Standby (SBY) mode. In Standby, the transponder is powered on and warming up but does not reply to radar interrogations, so the aircraft will not display a beacon return on the controller's radar.
Plain English
ATC is telling you to set your transponder to the Standby setting. The transponder stays on but stops sending replies to radar until you switch it back to an active mode.
Context Anchor
Heard in ATC radio communications when a controller wants the aircraft transponder temporarily stopped or reset from active use.
Derivation
‘Squawk’ comes from the World War II identification system nicknamed ‘Parrot,’ so telling an aircraft to ‘squawk’ became shorthand for operating the transponder. ‘Standby’ here is the labeled mode position on the transponder itself.
Why Pilots Care
Prevents unwanted replies or altitude broadcasts that could clutter ATC displays or reveal position when not intended.
Intuition Check
Standby does not mean simply 'wait for more instructions' here. It means select the transponder's standby mode, where it is ready but not actively replying to ATC radar.
Example Sentence 1
After clearing the runway, the tower instructed, ‘November Three Four Alpha, squawk standby,’ and the pilot rotated the transponder selector to SBY.
Example Sentence 2
After shutdown the pilot switched the transponder to squawk standby before securing the aircraft.