Definition
Ground-based sensors installed around an airport that measure wind speed and direction at the surface and along the boundary of the airport area, used to detect differences in wind between locations that may indicate wind shear or microburst activity near the runway environment.
Plain English
A network of wind sensors placed around an airport. By comparing what each one is reading, controllers can spot sudden wind changes that could be dangerous for landing or departing aircraft.
Context Anchor
Seen in wind shear discussions, especially when describing airport systems that warn pilots and controllers about changing wind across the airport surface.
Derivation
‘Boundary’ comes from the Old French ‘bonde,’ meaning a limit or edge. Here it refers to sensors placed around the edges of the airport, so the term simply describes wind sensors arranged along the airport boundary.
Why Pilots Care
They provide early warning of wind shear that can cause sudden loss of airspeed and lift during critical phases of flight.
Grounding Statement
Picture one wind reading near the middle of the airport and another near the edge showing a different wind; that mismatch is the warning clue.
Intuition Check
Do not read this as any general sign of wind near a boundary. In this context, it means specific airport wind indicators placed around the airport boundary and used to compare wind conditions across the airport.
Example Sentence 1
The tower issued a wind shear alert after boundary-wind indicators showed a sharp difference between the north and south sensors.
Example Sentence 2
Pilots checked the boundary-wind indicators during preflight to assess possible shear on departure.