Where are the oxygen overboard discharge indicator and servicing panel located?

• A. Left side only
• B. Right side only
• C. Both Left and Right sides
• D. Top of the fuselage

Answer: (C)

Oxygen system components are provided on both sides of the fuselage to ensure quick, convenient access for maintenance and operations, and to support redundancy in servicing and monitoring. The overboard discharge indicator shows when oxygen is venting to the outside, so having it on both sides lets crews visually confirm proper discharge from either side during checks or servicing. The servicing panel gives access to the oxygen system for refilling, inspection, and maintenance, and duplicating this panel on both sides means ground crews can service the system without having to reach a single location. Because of this symmetrical arrangement, both sides being equipped is the standard and practical setup.