Definition
TY is a NOTAM contraction used to indicate the type or category of an item being reported, such as the type of approach, equipment, lighting, or facility affected.
Plain English
TY is shorthand for the word 'type.' It tells you what kind of thing is being described in a NOTAM.
Context Anchor
Seen in FAA abbreviation lists and shortened pilot notices where space is limited.
Derivation
“Type” comes from an old word meaning a mark, model, or pattern. That helps here because a type is the pattern or kind something belongs to.
Why Pilots Care
NOTAMs are written in tight, abbreviated language. Knowing that TY simply means 'type' lets you read the message without stalling on the shorthand.
Intuition Check
TY does not mean typing on a keyboard here. It means the kind or classification of something being described.
Example Sentence 1
The NOTAM listed the TY of approach affected by the lighting outage.
Example Sentence 2
Pilots must enter the correct TY code when filing the flight plan.