In Class A airspace, operations must be conducted under which flight rules?

In Class A airspace, operations must be conducted under Instrument Flight Rules (IFR). This requirement is in place because Class A airspace exists from 18,000 feet MSL (Mean Sea Level) up to and including FL 600 (Flight Level 600), where weather conditions can vary considerably and are often unpredictable. IFR protocols ensure that pilots maintain safe separation from other aircraft and manage navigational responsibilities effectively in these altitudes where visual references can be limited.

Furthermore, Class A airspace is managed by air traffic control (ATC) to provide structured oversight and assistance, which is essential given the higher traffic volumes and complexity. Pilots operating in this airspace must possess an instrument rating, demonstrating proficiency in flying under conditions where visual reference to the ground is not possible due to weather or altitude.

Visual Flight Rules (VFR) and Special VFR are not applicable in this airspace as they are designed for operations where pilots can navigate and control the aircraft primarily by visual reference, which is not feasible in Class A. Experimental rules do not pertain to the requirements governing airspace classifications.