What term denotes a level of constant atmospheric pressure related to 29.92 inches of mercury, expressed as hundreds of feet?

• A. Flight Level
• B. Barometric Level
• C. Altitude Level
• D. Pressure Level

Answer: (A)

Flight level is the altitude reference tied to standard pressure. It designates a level of constant atmospheric pressure defined by the standard atmosphere at 29.92 inches of mercury, and it is expressed in hundreds of feet. That means a flight level indicates how many hundreds of feet above sea level the aircraft would be if the altimeter were set to 29.92 inHg, regardless of local weather pressure. For example, FL180 means 18,000 feet. This standardization is used to maintain vertical separation above the transition altitude when flying above areas where local pressure settings would vary. Other terms aren’t used to describe this standard pressure-based altitude reference.