FAA Airline Transport Pilot (ATM)Navigation, Air Traffic Control and ProceduresHard
A pilot flying an RNAV (GPS) approach loses situational awareness after a distraction and needs an immediate safe altitude reference using the Minimum Safe Altitude (MSA) circle depicted on the approach chart, centered on the IAF. What does the MSA guarantee, and how should it be used?
- A2,000 feet of obstacle clearance, but only in designated mountainous terrain
- B500 feet of obstacle clearance, and it may be used for extended climbs along the route
- C1,000 feet of obstacle clearance, authorized for use throughout the entire approach
- D1,000 feet of obstacle clearance within the specified radius, for emergency use only
Show answer & explanationAnswer & explanation
Correct answer: D. 1,000 feet of obstacle clearance within the specified radius, for emergency use only
The MSA provides 1,000 feet of obstacle clearance within the specified radius (typically 25 NM) of the reference facility or fix depicted on the approach chart. It is intended for emergency use only and does not guarantee navigation signal coverage or reflect an operationally usable altitude for normal approach segments.
Why the other options are wrong
- A. 2,000 feet is not the MSA standard, and MSA applies regardless of terrain type as charted.
- B. 500 feet is insufficient; MSA provides 1,000 feet, and it is not meant for extended use.
- C. MSA is not authorized for use during normal approach segments, only emergencies.
Minimum Safe Altitude (MSA)
An altitude depicted on an instrument approach chart providing 1,000 feet of obstacle clearance within a specified radius (usually 25 NM) of a reference facility or fix, intended for emergency use only.
- Provides 1,000 ft obstacle clearance within the charted radius
- Centered on a navigation facility, waypoint, or IAF
- Intended for emergency use only, not routine navigation
- Does not guarantee radio reception or communication coverage
Memory trick: 'MSA = My Safety Anchor' for emergencies only, 1,000 ft guaranteed