What is the "last assigned" altitude and how is it used during lost communications?

What is the "last assigned" altitude and how is it used during lost communications?

• A. The altitude of the highest terrain.
• B. The last altitude assigned by ATC to the aircraft.
• C. The altitude to descend to at the destination.
• D. The minimum IFR altitude.

Answer: (B)

When flying IFR and you lose radio contact, you follow the last altitude ATC cleared you to maintain. That last assigned altitude becomes the baseline you stay at until you either regain communications or receive a new clearance that changes it. This keeps you in line with what ATC had instructed and preserves proper separation from other traffic and terrain. The other options don’t fit because they aren’t the clearance you were given to follow during a communications failure. The altitude of the highest terrain is a safety consideration, not what ATC cleared you to. Descending to the destination’s altitude might violate the last clearance you held. The minimum IFR altitude is a safety floor for obstacle clearance, but it’s not the default you follow when you have a previously assigned altitude indicating a different level.

When flying IFR and you lose radio contact, you follow the last altitude ATC cleared you to maintain. That last assigned altitude becomes the baseline you stay at until you either regain communications or receive a new clearance that changes it. This keeps you in line with what ATC had instructed and preserves proper separation from other traffic and terrain.

The other options don’t fit because they aren’t the clearance you were given to follow during a communications failure. The altitude of the highest terrain is a safety consideration, not what ATC cleared you to. Descending to the destination’s altitude might violate the last clearance you held. The minimum IFR altitude is a safety floor for obstacle clearance, but it’s not the default you follow when you have a previously assigned altitude indicating a different level.