Definition

Airspace of defined dimensions identified by an area on the surface of the earth wherein activities must be confined because of their nature and/or wherein limitations may be imposed upon aircraft operations that are not a part of those activities.

Source: FAA JO 7110.65 ATC

Description

Special use airspace (sometimes referred to as "special use area(s)") is a general term that encompasses various types of segregated airspace where the activities performed within may impact air operations. Examples of such airspace types are:

• Prohibited area - flights in this airspace are prohibited, usually in order to protect some installation on the ground (e.g. a military base, a nuclear plant, etc.).
• Restricted area - flights in this airspace are allowed under certain conditions (e.g. if the aircraft is below certain MTOM or is performing a special mission, such as SAR).
• Danger area - the activities performed in this airspace are hazardous to flights (e.g. launching of anti-hail rockets, artillery firing, etc.).
• Temporary segregated area (TSA) - the airspace is reserved for a single user performing activities that may be hazardous to other traffic (e.g. airforce training, parachute jumping, etc.)
• Temporary reserved area (TRA) - similar to the TSA but crossing by other aircraft can be coordinated with the airspace user.
• Cross-border area (CBA) - similar to TRA and TRA but including airspace on both sides of international border. Normally used for joint activities by airforces of neighbouring states.

Information regarding the designation, use and activation of SUA can be found in national AIPs and other airspace-related documents, such as the Airspace Use Plan (AUP).