Question: A minimum safe altitude (MSA) is published for emergency use on instrument approach charts. Flying at or above the MSA will guarantee how many feet of obstacle clearance?
Answer: The MSA provides at least 1,000 feet of clearance over all obstructions within the radius published on the chart. The radius is typically 25 nautical miles but may be expanded to 30 nm where appropriate. (Source: Instrument Procedures Handbook Chapter 5, Page 18)