Definition
A reference number printed on an instrument approach procedure chart that identifies the specific revision of that procedure. The amendment number changes each time the FAA modifies the procedure, allowing pilots and chart publishers to confirm they are using the current version.
Plain English
A number on an approach chart that tells you which version of the procedure you're looking at. Every time the FAA updates the approach, the number changes.
Context Anchor
Seen on instrument approach procedure charts as part of the chart identification and revision information.
Derivation
From Latin emendare, 'to correct' or 'to free from fault.' An amendment is a change made to correct or update something. The number simply tracks which round of changes you're looking at.
Why Pilots Care
Ensures the pilot uses the latest version of the approach, which may contain critical safety or procedural changes.
Analogy
It is like a version number on a document. If two copies have different version numbers, you should not assume they contain the same information.
Intuition Check
Do not read amendment number as a score or a count you must calculate. Here it means the published version identifier for that approach procedure.
Example Sentence 1
Before flying the approach, the pilot checked that the amendment number on the chart matched the current published procedure.
Example Sentence 2
When the amendment number increased from 4 to 5, the old chart was discarded and replaced.