Instrument Rating Checkride Practice Test

What are the instrument hemispheric altitudes for flying at 0-179°?

1. Even thousands

2. Odd thousands

3. Variable depending on the aircraft type

4. No specific requirement

The correct answer is: Odd thousands

The correct answer, indicating odd thousands, relates to the rules governing altimeter settings in controlled airspace for instrument flight rules (IFR) operations. In the United States, the Federal Aviation Administration (FAA) specifies that when flying at altitudes from 0 to 179 degrees magnetic course, aircraft must maintain odd thousand-foot altitudes. This means that if a pilot is flying in this range, they would be at altitudes like 3,000 feet, 5,000 feet, 7,000 feet, and so forth. The rationale behind this system of odd and even altitudes is to promote vertical separation among aircraft navigating in opposite directions. For flights at magnetic courses between 180 and 359 degrees, even thousand-foot altitudes (like 4,000 feet, 6,000 feet, etc.) are specified. Understanding this system is crucial for maintaining safe distances from other aircraft, which is especially important in busy airspace. By adhering to these altitude rules, pilots contribute to the overall safety and efficiency of air traffic operations.