Definition
A long, thin pointer on an analog clock or aircraft clock that rotates continuously around the full face of the dial, marking off seconds as it moves. Unlike the hour and minute hands, it travels around the entire clock face once every 60 seconds, allowing precise timing of short intervals.
Plain English
The skinny, fast-moving needle on a clock that goes all the way around once a minute, ticking off the seconds.
Context Anchor
Seen in instrument flying when a pilot times a turn by watching the clock instead of relying only on outside visual references.
Derivation
Called a 'sweep' hand because it sweeps smoothly (or in steady ticks) across the entire clock face, rather than being confined to a small subdial. The word 'sweep' here refers to the wide arc it travels, covering the full dial.
Why Pilots Care
Supports accurate execution of timed turns at three degrees per second, allowing precise heading changes when visual references are unavailable.
Intuition Check
Do not read “sweep” as scanning the instruments or brushing across something. In this term, it means the seconds hand moving around the clock face.
Example Sentence 1
As the sweep second hand passed the 12, the pilot rolled into a standard-rate turn and began counting off 30 seconds for a 90-degree heading change.
Example Sentence 2
Noting the sweep second hand position allowed completion of the 180-degree timed turn in exactly one minute.