Definition
A phrase used by ATC to indicate that an instruction, clearance, procedure, or condition differs from what is normally expected or published. It alerts the pilot that something out of the ordinary is being issued and warrants closer attention.
Plain English
ATC is telling you, 'Heads up — what I'm about to give you isn't the usual thing.' It's a flag to listen carefully because the instruction or condition is different from normal.
Context Anchor
Seen in FAA airport, chart, procedure, and facility information when a runway, sign, light, marking, or procedure has a known difference from the usual standard.
Derivation
Standard comes from an old word for a fixed flag or point of reference. Over time it came to mean an accepted rule or normal model. Not Standard means the item does not match that accepted model.
Why Pilots Care
Pilots must follow the specific published instructions rather than defaulting to standard procedures, which affects planning, expectations, and safety margins.
Intuition Check
Do not read Not Standard as meaning unsafe or unusable by itself. It means the item does not match the normal FAA standard, so the pilot should pay attention to the published details.
Example Sentence 1
Tower advised 'right traffic, not standard' for Runway 27, so the pilot was careful to fly right-hand patterns instead of the usual left.
Example Sentence 2
The controller cleared us for a not standard traffic pattern due to construction on the normal runway.