Definition
Written, sequential lists of items and actions used by pilots to verify that critical tasks are completed correctly during each phase of flight. Checklists are a standard tool for ensuring that no required step is missed during preflight, start, taxi, takeoff, cruise, descent, landing, shutdown, or in response to abnormal and emergency situations.
Plain English
A printed or digital list of things a pilot must check or do at a specific point in flight, used in order so nothing important gets forgotten.
Context Anchor
Seen during preflight inspection, engine start, taxi, takeoff, cruise, landing, shutdown, and abnormal or emergency situations.
Derivation
From 'check' (to verify) plus 'list' (an itemized series). The aviation use grew out of military practice in the 1930s, after a fatal crash caused by missed configuration steps showed that even experienced pilots cannot reliably remember every item from memory.
Why Pilots Care
They reduce human error by making sure nothing important is missed, directly improving safety and preventing accidents.
Intuition Check
Do not think of a checklist as casual paperwork or a memory aid only. In aviation, a checklist is an operating tool used to confirm that required safety steps are completed.
Example Sentence 1
Before starting the engine, the pilot ran the Before Start checklist to confirm all switches and controls were properly set.
Example Sentence 2
When the engine lost power the crew pulled out the emergency checklist and completed each step in order.