Definition
Blocks of airspace, defined by published lateral and vertical limits, within which the flight of aircraft is not permitted at any time. Prohibited areas are established for reasons of national security or other interests of national welfare and are depicted on aeronautical charts with the letter P followed by an identifying number (e.g., P-56 over the White House and U.S. Capitol).
Plain English
A specific patch of sky you are not allowed to fly through, ever. The government has closed it off because flying there would create a security risk or threaten something important on the ground.
Context Anchor
Pilots encounter prohibited areas during preflight planning and on aeronautical charts when choosing a safe and legal route.
Derivation
From the Latin prohibere, meaning 'to hold back' or 'forbid.' The word carries the strongest possible sense of 'not allowed' — stronger than 'restricted,' which only sometimes blocks entry. That distinction matters here: prohibited means closed, period.
Why Pilots Care
Entering without authorization violates federal regulations and can trigger interception or enforcement action.
Intuition Check
Do not read “prohibited” as “not recommended” or “use caution.” In this FAA context, it means flight through that airspace is not allowed unless specifically authorized.
Example Sentence 1
While planning the cross-country, the student noticed P-40 near Camp David and adjusted the route to remain well clear of the prohibited area.
Example Sentence 2
Only aircraft with prior clearance from the controlling agency may enter a prohibited area.