In the context of aviation and aerospace, the Air Defense Command (ADC) refers to a military organization responsible for detecting, tracking, and engaging airborne threats, such as enemy aircraft, missiles, and drones, to protect a nation's airspace and territory.

The primary mission of an Air Defense Command is to:

1. Detect and identify airborne threats using radar, sensors, and other surveillance systems.
2. Track and monitor the movement of these threats to determine their intent and potential impact.
3. Engage and neutralize or destroy the threats using surface-to-air missiles, anti-aircraft artillery, or fighter aircraft.

The Air Defense Command typically consists of several components, including:

1. Surveillance and detection systems, such as radar and early warning systems.
2. Command and control systems, which coordinate the response to airborne threats.
3. Air defense missile and artillery systems, such as surface-to-air missiles and anti-aircraft guns.
4. Fighter aircraft, which can be scrambled to intercept and engage enemy aircraft.

The Air Defense Command plays a critical role in national defense, as it helps to protect against airborne threats, such as:

• Enemy aircraft, including bombers, fighters, and reconnaissance planes.
• Ballistic and cruise missiles.
• Drones and unmanned aerial vehicles (UAVs).
• Other aerial threats, such as helicopters and transport aircraft.

In the United States, the Air Defense Command was a major command of the United States Air Force (USAF) from 1946 to 1975, responsible for defending the country's airspace against airborne threats. Although the command was disestablished in 1975, its functions and responsibilities have been absorbed by other USAF organizations, such as the North American Aerospace Defense Command (NORAD) and the Air National Guard.