Air navigation charts have clearly delineated areas which depict restricted airspace. Air traffic control in a given region will notify pilots of their proximity to such areas before the line has actually been crossed.
Once an aircraft approaches restricted airspace, air traffic control will contact the crew by radio and warn them to turn away. Pilots are obliged to respond to these warnings. If there is no response and the plane crosses into restricted airspace, the air traffic controller notifies the nearest military airfield. The airfield will dispatch fighter aircraft.
Fighter aircraft will approach the aircraft in violation and take a predetermined intercept position and identify themselves by radio. If no contact can be made or if the pilot is unwilling to follow orders, the intersecting aircraft will take a more aggressive stance and attempt to force the aircraft into a positive response.
If there is still no response or attempt by the unauthorized aircraft to return to unrestricted airspace, the interceptor aircraft may be called on to fire on the aircraft to prevent imminent attack or harm to persons or sensitive targets on the ground or in the air. Interceptor aircraft will respond with differing levels of aggression depending on the situation, air space and the aircraft in question.
