FAA Instrument Flight Instructor (FII)Instrument RegulationsEasy
During an emergency descent in IMC, a pilot references the Minimum Safe Altitude (MSA) circle depicted on the approach chart. What does this altitude provide?
- AGuaranteed navigation signal reception throughout the sector
- B1,000 feet of obstacle clearance within 25 NM of the reference facility, for emergency use only
- CA planned descent altitude usable for normal approach procedures
- DThe minimum altitude ATC will assign during radar vectoring
Show answer & explanationAnswer & explanation
Correct answer: B. 1,000 feet of obstacle clearance within 25 NM of the reference facility, for emergency use only
The MSA depicted on an instrument approach chart provides at least 1,000 feet of obstacle clearance within a 25 NM radius of the reference navigation facility or fix, and is intended for emergency use only, not for normal approach planning or navigation guidance.
Why the other options are wrong
- A. MSA does not guarantee navigation signal reception, only obstacle clearance.
- C. MSA is not intended for use in normal approach planning.
- D. MSA is a charted reference, not an ATC-assigned vectoring altitude.
Minimum Safe Altitude (MSA)
The MSA depicted on an instrument approach chart provides 1,000 feet of obstacle clearance within 25 NM of a specified navigation facility or fix, for emergency use only.
- 1,000 ft obstacle clearance minimum
- 25 NM radius from the reference facility/fix
- Emergency use only, not for normal navigation or descent planning
Memory trick: '25 and 1,000' — MSA's emergency safety net.