What does minimum safe altitude (MSA) provide on approach charts?

• A. The minimum altitude for the intermediate segment.
• B. The minimum altitude depicted on approach charts providing at least 1,000 feet of obstacle clearance within a specified distance from the facility.
• C. The altitude of the missed approach point.
• D. The altitude to begin a circling approach.

Answer: (B)

Minimum safe altitude on approach charts is the altitude you can descend to within a defined distance from the navigation facility that guarantees obstacle clearance. Specifically, it provides at least 1,000 feet of clearance (2,000 feet in mountainous terrain) within about 25 nautical miles of the facility. On the chart, these MSAs are shown in sectors around the facility to ensure you have safe clearance if you’re within that radius and not yet established on the exact approach. This is different from the altitude for the intermediate segment, the altitude at the missed-approach point, or the circling minimums.