The designation R1 refers to which of the following doors?

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

Answer: (C)

R1 designates the door on the right side of the aircraft that is at the forward position. The letter indicates the side (R for right) and the number shows the door’s position along the fuselage, with 1 being the forward-most door on that side. Therefore, it’s the forward service door on the aircraft’s right side, typically used for galley/service access rather than passenger boarding.