Definition
A National Security Area is a defined block of airspace established at locations where there is a requirement for increased security and safety of ground facilities. Pilots are requested to voluntarily avoid flying through these areas. When circumstances require a more stringent measure, flight may be temporarily prohibited under 14 CFR 99.7.
Plain English
An area of airspace around a sensitive ground site where pilots are asked to stay clear voluntarily. If the situation gets serious enough, the FAA can make avoiding it mandatory.
Context Anchor
Seen on aeronautical charts and during preflight planning, especially when checking the route for security-related airspace restrictions.
Why Pilots Care
Failing to avoid these areas can lead to interception by military aircraft or other security responses.
Intuition Check
Do not read NSA here as the National Security Agency, and do not assume it is always permanently closed airspace. In FAA airspace use, an NSA is a security-related airspace area that pilots are usually asked to avoid, unless a current restriction makes avoidance mandatory.
Example Sentence 1
While planning the route, the pilot noticed a National Security Area near the power plant and adjusted the course slightly to remain clear.
Example Sentence 2
During preflight planning, the student identified the NSA around the nuclear facility and planned an alternate route.