Definition
Critical action steps in an emergency or abnormal procedure that a pilot must perform immediately from memory, without first referring to a written checklist, because the situation does not allow time to locate and read the checklist before acting.
Plain English
The handful of urgent steps a pilot has to know by heart and do straight away when something goes wrong, before reaching for the checklist.
Context Anchor
Seen in emergency and abnormal checklists, especially when the first actions must be taken before there is time to read the full checklist.
Derivation
From 'memory' (held in the mind, no reference needed) and 'items' (individual steps or actions). Together: the steps you must hold in your mind ready to act on, because time will not allow looking them up.
Why Pilots Care
Immediate execution of these steps can prevent further damage or loss of control when every second counts.
Intuition Check
Do not assume memory items mean the whole checklist should be done from memory. They are only the immediate actions that must be known cold; the written checklist is still used afterward when time permits.
Example Sentence 1
After the engine failure, the pilot performed the memory items -- pitch for best glide, fuel selector, mixture, ignition -- before pulling out the emergency checklist to confirm each step.
Example Sentence 2
The checklist required the memory items to be completed before the pilot reached for the written procedure.