Definition
The crosswind leg of the airport traffic pattern when entered from outside the pattern by crossing over the runway at pattern altitude near the middle of the runway, then turning to fly perpendicular to the runway on the upwind side before joining the downwind leg.
Plain English
It is the point where a pilot flies across the runway at the middle, at pattern height, and then turns to fly across the wind before joining the normal traffic flow around the airport.
Context Anchor
Used when discussing traffic-pattern entries at non-towered airports, especially when a pilot is joining the pattern from the opposite side of the runway.
Derivation
Midfield' simply means the middle of the airfield, and 'crosswind' refers to the leg of the pattern flown across the wind, perpendicular to the runway. Together they describe both where the crossing happens and which leg of the pattern it becomes.
Why Pilots Care
Allows other pilots to know your exact location so they can avoid conflicts while entering or flying the pattern.
Intuition Check
Do not read “midfield crosswind” as a wind condition at the middle of the field. Here, it describes the airplane’s path across the runway area near midfield.
Example Sentence 1
Arriving from the north with a south-side downwind in use, the pilot crossed midfield at pattern altitude and turned onto the midfield crosswind before joining the downwind for Runway 27.
Example Sentence 2
An aircraft reporting midfield crosswind lets others time their downwind entry safely.