Definition
Instrument approach procedure charts published for use by civil (non-military) pilots, depicting the routes, altitudes, courses, and minimums required to fly a specific instrument approach into an airport. In the United States, these are produced by the FAA and by commercial providers such as Jeppesen.
Plain English
The printed or digital pages that show a pilot exactly how to fly an instrument approach into an airport, made for civilian flying rather than military.
Context Anchor
Seen in instrument flying, chart briefings, and FAA chart margin information when identifying the type of approach chart being used.
Derivation
Civil' here means non-military (from Latin civilis, relating to citizens). 'Approach plate' is long-standing aviation slang for an instrument approach chart -- 'plate' refers to a printed page, originally a metal printing plate. So 'civil approach plates' simply means approach charts for civilian use, as opposed to military versions.
Why Pilots Care
These charts contain the legally required information for flying an instrument approach -- courses, altitudes, missed approach procedures, and minimums. Flying an approach without the correct, current plate is unsafe and not legal under instrument flight rules.
Intuition Check
Civil does not mean “polite” here. It means the approach chart is for non-military aviation use, as opposed to a military procedure or chart.
Example Sentence 1
Before starting the approach, the pilot pulled up the civil approach plate for the ILS to runway 27.
Example Sentence 2
Before departure the instructor confirmed they had the current civil approach plates for the planned alternate.