Definition
A small metal vane or plate fitted near the static port opening to prevent rain, ice, dirt, or other foreign matter from entering the static system, while still allowing ambient air pressure to reach the static line.
Plain English
A little shield placed at the static port that blocks rain and debris from getting inside, but still lets outside air pressure through so the instruments can sense it.
Context Anchor
Seen in diagrams of the pitot/static system, especially the internal parts of a pitot tube connected to the airspeed indicator.
Derivation
From the verb 'baffle,' meaning to block, deflect, or restrain. The plate baffles (deflects) unwanted material away from the opening.
Why Pilots Care
Keeps water out of the lines so airspeed and altitude instruments continue to read correctly in rain or after flying through clouds.
Analogy
It is like a small splash guard inside a pipe: the pressure can still pass through, but water or debris is less likely to go straight down the line.
Intuition Check
Do not read “baffle” as meaning “confuse” here. In this context, a baffle plate is a physical shield that deflects or blocks unwanted flow without stopping the needed air pressure.
Example Sentence 1
During preflight, the pilot checked that the static port and its baffle plate were free of dirt, insects, and ice.
Example Sentence 2
During the preflight inspection the pilot verified that the baffle plate drain hole was clear so moisture could escape.