What is the function of a part-time tower indicated in an IAP?

A part-time tower indicated in an Instrument Approach Procedure (IAP) signifies that the air traffic control tower operates only during certain hours or under specific conditions. This means that the tower may be staffed and providing air traffic services at designated times but is not continuously operational around the clock.

The essential function of a part-time tower is to facilitate limited operations based on the predetermined schedule, accounting for factors like traffic volume and operational needs. During the hours when the tower is closed, pilots flying in and out of that airport may need to operate without live air traffic control assistance, often relying on procedures for uncontrolled airports or coordinating with other traffic as necessary.

This information is crucial for pilots when planning their arrivals and departures, as they must be aware of the times the tower is open for operations to ensure compliance with air traffic instructions and procedures.