AIM 4-1-5 Communications Release of IFR Aircraft Landing at an Airport Without an Operating Control Tower
Chapter 4. Air Traffic Control · Section 1. Services Available to Pilots
A reference copy of the official AIM text for study. It is not legal advice or an FAA interpretation; always confirm against the current official source.
Aircraft operating on an IFR flight plan, landing at an airport without an operating control tower will be advised to change to the airport advisory frequency when direct communications with ATC are no longer required. Towers and centers do not have nontower airport traffic and runway in use information. The instrument approach may not be aligned with the runway in use; therefore, if the information has not already been obtained, pilots should make an expeditious change to the airport advisory frequency when authorized.
REFERENCE-
AIM, Para 5-4-4, Advance Information on Instrument Approach.