What must be published and functioning for an airport to request a Contact Approach?

For an airport to request a Contact Approach, a published instrument approach is essential. This requirement exists because a Contact Approach is a procedure that allows pilots to navigate visually while remaining under instrument flight rules (IFR). The procedure is initiated when pilots have the desired vertical and lateral weather conditions and can achieve visual contact with the airport or its environment.

The necessity of having a published instrument approach ensures that there is an established procedure for arriving aircraft, allowing air traffic control (ATC) to safely guide the aircraft towards the approach path. This helps in maintaining safety standards and streamlining operations, as the pilots must be familiar with the published approach to transition from IFR to visual navigation effectively.

Having a published approach plate is critical to provide necessary information like altitudes, airspeeds, and navigational guidance, which assists the pilots in navigating safely during the approach phase. The other choices do not specifically address the need for a structured approach procedure recognized in IFR operations, which is central to facilitating a Contact Approach.