Which door is designated as R1 in aircraft door labeling?

• A. Aft service door, aircraft left
• B. Forward service door, aircraft left
• C. Aft service door, aircraft right
• D. Forward service door, aircraft right

Answer: (D)

R1 designates the first door on the right side of the aircraft when looking forward. Doors are labeled by side (Right) and numbered from the nose toward the tail, so the forwardmost door on the right is R1. This door is typically a forward service door used for catering or crew access. Doors on the left side or further toward the rear would have different designations, so they are not R1.