Which term denotes the altitude published to ensure obstacle clearance for a given area?

• A. Minimum Safe Altitude
• B. Minimum Reception Altitude
• C. Mean Sea Level
• D. Military Training Route

Answer: (A)

The altitude published to ensure obstacle clearance for a given area is the Minimum Safe Altitude. This figure on IFR charts provides a guaranteed buffer above terrain and obstacles in a defined region—typically enough clearance to protect you within about 25 miles of a navigation aid, commonly 1,000 feet in non-mountainous areas or 2,000 feet in mountainous regions. It’s there to keep you safe if you’re uncertain of your exact route or if you momentarily lose navigation signal. In contrast, Minimum Reception Altitude relates to reliable nav signal reception, Mean Sea Level is just the reference height, and Military Training Route pertains to airspace used for training.