What is the maximum altitude associated with the term flight level?

• A. 12,000 ft.
• B. 20,000 ft.
• C. 17,999 ft.
• D. Over 18,000 ft.

Answer: (D)

Flight levels are altitudes expressed with a standard pressure setting (29.92 inHg), used for en-route separation above the transition altitude. In the U.S. the transition to standard pressure begins at 18,000 feet, so flight levels start at 18,000 feet and continue upward. That makes the term inherently associated with altitudes above (and including) 18,000 feet. Therefore, the best description is altitudes over 18,000 ft. You’ll see designations like FL180, FL200, and so on for higher levels.