Prohibited areas
What prohibited areas are, why they exist, and the consequences of entering one.
A prohibited area is special-use airspace within which flight is not allowed at all. They are established for reasons of national security or welfare — protecting sensitive sites such as the White House and U.S. Capitol (P-56), Camp David (P-40), and certain other government installations.
Prohibited areas are charted with a blue hatched boundary and labeled with a "P-" number (e.g. P-56A/B over Washington, D.C.). The chart margin or Chart Supplement lists the designated altitudes (often surface to unlimited) and the times of designation, which for prohibited areas is typically continuous.
There is no "request permission to enter" for a prohibited area in normal operations — the answer is no. Violations are taken extremely seriously: the airspace around Washington in particular is layered with a Flight Restricted Zone (FRZ) and a Special Flight Rules Area (SFRA), and incursions can trigger an armed intercept and certificate action.
The practical airmanship point: study your route for any "P-" areas during preflight, give them a wide berth, and remember that GPS direct lines can clip a prohibited area's corner. When flying near Washington, D.C., complete the required online SFRA training and follow the special procedures to the letter.
*Reference and training only. Consult current charts, NOTAMs and the FAA AIM.*