We’ve got another Part 107 video test prep question of the week. This week we are dealing with question on airspace, specifically what happens at an airport with a part-time tower when the tower isn’t operating?
The question is:
Outside control tower hours Class D airspace is:
- either class G & or E
- stays the same
- Class A airspace
To be clear this is only in situations where an airport has a part-time tower, where it does not operate all the time.
First, it is not the last answer because Class A airspace only exists at and above 18,000 feet MSL to 60,000 or what is called flight level 600 (drop the last two zeros).
The second answer is also incorrect because it does not continue to be Class D airspace outside or control tower hours.
So, this means that the first answer is correct. When a control tower at a Class D airport is not operating, the airspace becomes either Class G or Class E airspace. But how do we know which one a specific airport changes to? Glad you asked.
Know Your Sources of Airport Information
There is a source of information called the Aeronautical Information Manual (AIM). In this manual there is a section that says:
At those airports where the control tower does not operate 24 hours a day, the operating hours of the tower will be listed on the appropriate charts and in the Chart Supplement U.S. During the hours the tower is not in operation, the Class E surface area rules or a combination of Class E rules to 700 feet above ground level and Class G rules to the surface will become applicable. Check the Chart Supplement U.S. for specifics.
To put this in terms that are more clear, if you’re flying near an airport that has a part-time tower, you’re actually going to want to check the airport facility directory (AFD). The AFD will give you details on that specific airport.
Just by way of example, below is the AFD information for the airport with the identifier KPRC. Although this information appears to be old, it is a good example of the AFD providing the answer to this question. As you can see, outside of tower hours, the airspace reverts to Class E airspace.
The good news about a question like this is that the FAA would have to give you the AFD information for you to make a determination about whether a part-time tower airport reverts to Class G or Class E airspace. If you need a quick refresher on airspace, check out our article on airspace classifications.
As long as you know that the airspace changes to class E and/or Class G, you should be good on the test.
