MCD stands for Main cabin door.

MCD stands for Main cabin door.

• A. Main cabin door
• B. Main control device
• C. Median cabin doorway
• D. Maximum cabin door

Answer: (D)

MCD is used in aviation to refer to the Main Cabin Door—the primary door used for passenger boarding and deplaning. This is the standard expansion you'll see in crew communications and cabin procedures, so recognizing it as “Main Cabin Door” helps you quickly identify the door involved in boarding, deplaning, and, in emergencies, evacuations. The other phrases aren’t standard terms in airline contexts—they don’t describe a door used for passengers, so they aren’t correct expansions of this acronym.

MCD is used in aviation to refer to the Main Cabin Door—the primary door used for passenger boarding and deplaning. This is the standard expansion you'll see in crew communications and cabin procedures, so recognizing it as “Main Cabin Door” helps you quickly identify the door involved in boarding, deplaning, and, in emergencies, evacuations. The other phrases aren’t standard terms in airline contexts—they don’t describe a door used for passengers, so they aren’t correct expansions of this acronym.