Which flight level is listed as a warning threshold for descents outside the FAF?

Which flight level is listed as a warning threshold for descents outside the FAF?

• A. FL180
• B. FL200
• C. FL240
• D. FL100

Answer: (A)

Descent timing before the final approach fix is guarded by a warning trigger that tells you not to descend while you’re still outside the final approach segment. The number chosen for this warning is tied to the standard transition level used in many airways and approaches, which is 18,000 feet—represented as FL180 in flight levels. Using FL180 as the warning threshold ensures you’re alerted if you try to descend before you’ve reached the proper segment of the approach, helping maintain the required obstacle clearance and proper sequencing.

So, the reason this level is correct is that it aligns with the common transition altitude/level framework and provides a clear, standardized point to warn about premature descents outside the FAF. The other options don’t serve that standard role as the primary warning level for this scenario.