FAA Ground School Practice Test

To determine the height of the base of the ceiling in relation to the terrain elevation of 1295 feet Mean Sea Level (MSL), it is essential to understand the relationship between MSL and Above Ground Level (AGL).

The elevation given corresponds to the ground level or terrain height. When we talk about AGL, we are measuring the height above that terrain level. The question requires us to find out how high the ceiling is above the ground.

In this case, the value of 505 feet AGL means that when you start from the terrain height of 1295 feet MSL and then go to a height of 505 feet above that terrain, the overall height from MSL would be:

1. Start with the terrain elevation: 1295 ft MSL.

2. Add the AGL height: 505 ft AGL.

This gives a total of 1295 + 505 = 1800 ft MSL.

Therefore, the provided figure of 505 feet AGL correctly indicates the height of the base of the ceiling above the terrain elevation of 1295 ft MSL. This is why this answer is logically consistent and accurate based on the ceiling reference in aviation, which measures from the ground level (