Final answer:
Flight Level 180 (FL180) represents 18,000 feet, Flight Level 190 (FL190) represents 19,000 feet, and Flight Level 200 (FL200) represents 20,000 feet. The altimeter ranges for these flight levels indicate the altitude above mean sea level at which the aircraft is flying. The alimeter range is dependent on atmospheric conditions affecting air density.
Step-by-step explanation:
The altimeter setting for aircraft is a crucial aspect of maintaining proper separation from other aircraft and terrain during flight. Flight levels are standardized layers of airspace used by aircraft for navigation in the altitude range above 29,000 feet (8,850 meters) where the air is too thin for a standard barometer to be useful. The flight level is indicated by a three-digit number representing hundreds of feet.
For example, Flight Level 180 (FL180) would represent 18,000 feet, Flight Level 190 (FL190) would be 19,000 feet, and Flight Level 200 (FL200) indicates 20,000 feet. While I have mentioned the specific altitudes for the flight levels you asked about, it's worth noting that the precise altimeter range for any given flight level will depend on specific aircraft instrumentation and the current atmospheric conditions, which can affect air density.
Given this, referencing a Table A3 related to Altitude to Air Density Relationship could provide data on the expected air density at these altitudes which is helpful for understanding the performance of an aircraft's systems and how it may be affected by the density of the air.