Class A Airspace is a type of controlled airspace that extends from 18,000 feet up to 60,000 feet above sea level. It is primarily used by commercial airliners and other high-altitude aircraft. In this airspace, pilots must operate under instrument flight rules (IFR), meaning they rely on instruments for navigation and cannot fly solely by visual reference. To enter Class A Airspace, pilots must obtain an air traffic control (ATC) clearance. This ensures safe separation between aircraft and helps manage the high volume of traffic in this busy airspace. All aircraft operating in Class A Airspace must be equipped with specific communication and navigation equipment.