Definition
Published altitudes depicted on instrument approach charts that provide at least 1,000 feet of obstacle clearance within a specified distance (typically 25 nautical miles) from a designated reference point on the airport, such as a navigation aid or airport reference point. They are intended for emergency use only and do not guarantee navigation signal coverage or communications.
Plain English
These are altitudes printed on approach charts that tell a pilot how high to fly to safely clear obstacles near an airport in an emergency. They are a backup, not a normal part of the approach.
Context Anchor
Seen in instrument procedure information and chart records where the FAA lists altitude references for the area around an airport.
Why Pilots Care
They give pilots a known safe altitude to descend to when they cannot receive further ATC instructions or when visibility is lost.
Grounding Statement
Think of these altitudes as an emergency floor for the airport area: stay at or above the floor to preserve obstacle clearance while you sort out the problem.
Intuition Check
“Safe” does not mean safe for every purpose or every phase of flight. Here it means the altitude provides obstacle clearance in the stated airport area, usually as an emergency reference, not as permission to fly that altitude in place of a clearance or procedure altitude.
Example Sentence 1
After losing communications during the approach, the pilot climbed to the published minimum safe altitude shown on the chart for that sector.
Example Sentence 2
The approach chart listed an airport minimum safe altitude of 2,800 feet within 25 miles of the VOR.