When is CTAF used at KSDL?

The correct answer is that CTAF (Common Traffic Advisory Frequency) is used at KSDL after hours when the tower is closed. This is because CTAF is utilized in uncontrolled environments or when air traffic control services are not available. After the tower closes, pilots communicate on CTAF to announce their intentions and maintain situational awareness among other pilots in the vicinity of the airport, ensuring safe operations.

During hours when the tower is open, pilots are typically required to communicate with the control tower instead of using CTAF. The use of CTAF is essential in maintaining safety and efficiency in the airspace surrounding an airport when there are no air traffic controllers available to manage the traffic. Therefore, operating on CTAF when the tower is closed allows for continued coordination and communication among pilots.