What is the Mandatory altitude?

• A. An altitude depicted on an instrument approach chart with the altitude value underscored and overscored; aircraft are required to maintain altitude at the depicted value.
• B. An altitude that must be avoided during the approach.
• C. An altitude indicating minimum obstacle clearance.
• D. An altitude used for determining fuel planning.

Answer: (A)

A mandatory altitude is an altitude published on an instrument approach chart that must be maintained at a specified point or segment. It is shown with the altitude value underscored and overscored, and you are required to stay at or above that altitude until you reach the next published altitude or fix where a new clearance applies. This designation ensures obstacle clearance and proper sequencing as you proceed through the approach. It isn’t an altitude to avoid, nor a general route-wide obstacle clearance altitude, nor something used for fuel planning.