Commercial Checkride Practice Test 2025 - Free Practice Questions and Study Guide

Class A airspace is defined as the airspace from 18,000 feet mean sea level (MSL) up to and including 60,000 feet MSL. This specific range is crucial for maintaining safe and orderly flow of air traffic, particularly among high-altitude commercial flights that are flying under Instrument Flight Rules (IFR). In Class A airspace, all aircraft must operate under IFR, which provides regulations for safe navigation alongside other aircraft in this busy and controlled environment.

The minimum altitude begins at 18,000 feet MSL because this level is where the airspace becomes significantly more congested due to commercial airline traffic. Above 60,000 feet MSL, the airspace is less structured and does not fall under Class A rules. Therefore, the altitude range specified in the correct answer accurately reflects the regulatory framework for Class A airspace, ensuring pilots and air traffic controllers are aware of the operational requirements and environment at these altitudes.