Not all checklist items are equal. Most protect against inconvenience. A few protect against a smoking hole. Those are the killer items, and a good checklist makes sure they show up in the phase where forgetting them kills you.
The usual suspects
- GEAR, down and confirmed before landing. The most expensive thing you can forget in a retractable.
- FUEL, selector on the fullest usable tank before takeoff and before landing. Running a perfectly good airplane out of usable fuel is heartbreakingly common.
- FLAPS and TRIM, set for takeoff. A mis-set trim on rotation is a control emergency at the worst altitude.
- FLIGHT CONTROLS, free and correct before every takeoff. Thirty seconds buys you out of a controls-jammed takeoff.
- DOORS and HARNESSES, secured before takeoff. Rarely deadly on its own, but a popped door has distracted pilots right into the ground.
Killer items earn their spot on a short list. When you're cutting to keep a checklist usable, you cut convenience items. Never these.