What does the S mean in a WRB element?

• A. AOG or OSS
• B. Start of schedule
• C. Schedule status
• D. Special order service

Answer: (A)

In this context, the S in a WRB element signals a special urgent category that triggers expedited handling. Specifically, it denotes AOG (Aircraft on Ground) or OSS, meaning the item or service is needed to get an aircraft back in the air or to support critical, time-sensitive operations. This flag is used to route and prioritize these requests so they receive faster attention and resources. Other options don’t align with how WRB coding uses S for urgent, critical scenarios, such as scheduling terms or a generic “special order service,” which aren’t the standard meaning tied to WRB elements.