What does the term "APRX" in a NOTAM signify?

The term "APRX" in a NOTAM indicates that the information provided is estimated or approximate, specifically in context to its validity until it is either cancelled or replaced. This means that the NOTAM will remain effective unless the issuing authority sends out another NOTAM that specifically cancels it or provides updated information.

Using "APRX" helps to communicate that pilots and other aviation personnel should remain aware of the content's provisional nature and should expect that it could change, but they can rely on the current NOTAM until they receive official notification otherwise. This emphasizes the continual need for vigilance and up-to-date information in aviation operations, particularly concerning changes that could affect safety and flight planning.