What is the purpose of the Minimum Safe Altitude (MSA) during IAPs?

The purpose of the Minimum Safe Altitude (MSA) during Instrument Approach Procedures (IAPs) is to ensure obstacle clearance. MSA is specifically designed to provide a safe altitude for aircraft in the vicinity of an airport, offering a buffer against obstacles and terrain during the approach. By maintaining this altitude, pilots can safely navigate around potential hazards while executing their approach procedures.

MSA values are established based on the highest obstacle in a given area, ensuring that there is a safe vertical separation between the aircraft and any obstacles present. This is particularly important in diverse and challenging environments where terrain and structures can pose risks during an approach.

While minimum flight altitudes and landing clearances are certainly critical elements of flight operations, they serve different purposes. Navigation frequencies do not relate to altitude directly, but rather concern communication and navigational aids. Thus, MSA's primary function is firmly rooted in the safety of the aircraft with respect to obstacles, making obstacle clearance its defining purpose.