What must a pilot do before entering Class D airspace?

Answer: C — Contact the tower for clearance to enter

Before entering Class D airspace, a pilot is required to contact the control tower for clearance to enter. Class D airspace is typically found around airports with an operational control tower, and its primary purpose is to ensure the safety and efficient movement of air traffic in the vicinity of the airport. By contacting the tower, pilots receive instructions that help manage the flow of traffic and reduce the risk of conflicts with other aircraft. The process involves the pilot providing their intentions and receiving an explicit clearance to enter the airspace. This communication helps the tower manage incoming and outgoing flights, ensuring that all aircraft operate safely in what can be a busy environment. It’s essential for maintaining order in the airspace and following established protocols set by the FAA. Filing a flight plan, switching to approach frequency, or contacting ground control are not necessary steps for entering Class D airspace, though they may have relevance at different stages of the flight or in specific circumstances. For example, filing a flight plan is more relevant for VFR flight in controlled airspace rather than a prerequisite for entering Class D. Ground control usually manages surface operations and doesn't provide the clearance needed for entering controlled airspace.