Definition
On aeronautical charts, a series of short, tooth-like tick marks drawn along a line — typically a Victor airway — used to identify and locate an intersection along that route.
Plain English
Tiny tooth-shaped marks on a chart that show where an intersection sits along an airway.
Context Anchor
Seen on IFR en route charts and instrument procedure charts when a fix or intersection is identified using a reference line from a navigation aid.
Derivation
From Latin 'serra' meaning saw. The marks look like the teeth of a saw blade, which is why they're called serrations.
Why Pilots Care
Accurate identification of intersections confirms you are on the correct airway segment and at the proper fix for altitude or routing changes.
Intuition Check
Do not read serrations as damage, terrain, or a rough surface. On an instrument chart, they are intentional tooth-like marks that identify a reference line used to locate a navigation point.
Example Sentence 1
The serrations along the airway pointed toward the VOR whose radial formed the intersection.
Example Sentence 2
When the DME read 12 miles, the serrations on the chart lined up with the second VOR radial, verifying the fix.