Definition
In airspace terminology, 'prohibited' describes a designated block of airspace within which the flight of aircraft is not allowed, except by specific authorization from the controlling agency. A Prohibited Area is established for reasons of national security or welfare and is depicted on aeronautical charts with a 'P' followed by an identifying number (for example, P-56 over the White House).
Plain English
Aircraft are not permitted to fly through this airspace at all, unless they have been given specific permission. It is the strictest type of airspace restriction.
Context Anchor
Seen on aeronautical charts, in airspace descriptions, and in routing or clearance discussions when an aircraft must avoid an area or action that is not allowed.
Derivation
From the Latin 'prohibere,' meaning 'to hold back' or 'forbid' (pro- 'away' + habere 'to hold'). In aviation use, it carries the strongest sense of the word: entry is forbidden outright, not merely discouraged or conditional.
Why Pilots Care
Entering a Prohibited Area without authorization can result in interception by military aircraft, certificate action, and in sensitive areas, a serious national security response. Unlike Restricted Areas, there is no 'when not active' window — Prohibited Areas are always off-limits without specific clearance.
Intuition Check
Do not read prohibited as “not recommended” or “use caution.” In aviation, prohibited means the operation is not allowed unless a specific authorization makes it legal.
Example Sentence 1
While planning the route, the pilot noticed a Prohibited Area near the destination and adjusted the flight path to remain well clear.
Example Sentence 2
ATC advised the flight to turn immediately to avoid entering prohibited airspace.