RJet Cadet Interview Practice Test

MSA defines the altitude needed to guarantee obstacle clearance inside a specific circle around a navigation aid. That circle has a radius of 25 nautical miles. Within this 25 NM zone, the minimum altitude shown as MSA ensures you have safe clearance over terrain and obstacles, making it a reliable reference when flying near the nav aid. It’s not about a larger radius or outside the circle, and it does relate to terrain elevations because the purpose is to maintain obstacle clearance.