Which of the following is true regarding flight operations in Class A airspace?

In Class A airspace, it is mandatory for aircraft to operate under instrument flight rules (IFR). This requirement ensures a high level of safety and efficiency in a highly controlled environment, as Class A airspace typically extends from 18,000 feet up to and including 60,000 feet above mean sea level. Given the complexity of operations at these altitudes, including the potential for heavy traffic and reliance on air traffic control for navigation and separation, adherence to IFR is essential.

Operations under visual flight rules (VFR) are not permitted in Class A airspace, as the visual conditions needed for VFR cannot be guaranteed at these altitudes. While some equipment requirements exist, such as the need for radar transponders and other navigational aids, the key feature distinguishing Class A operations is the requirement for IFR.