Definition
Northbound describes an aircraft, route, or traffic flow moving in a generally northerly direction. In aviation publications, charts, and NOTAMs, NB is used as a shorthand to indicate the direction of travel, often when describing airways, traffic patterns, runway flows, or restricted airspace activity.
Plain English
Heading north, or flying toward the north.
Context Anchor
Seen in shortened aviation notices, route descriptions, airport notes, and other compact written information where directions are abbreviated.
Derivation
From 'north' (the cardinal direction) plus '-bound,' an old English suffix meaning 'ready to go' or 'headed toward.' The same pattern gives us eastbound, westbound, and southbound.
Why Pilots Care
Prevents navigation errors by making directional instructions unambiguous in routing and position reports.
Intuition Check
Northbound does not always mean an exact 360-degree heading. It means the overall direction of movement is toward the north.
Example Sentence 1
The NOTAM advised that NB traffic on V23 should expect holding due to weather near the next reporting fix.
Example Sentence 2
The controller cleared the helicopter to continue NB at 2,000 feet.