Dual channel in ______ mode is prohibited.

• A. FMC tactical
• B. FMC automatic
• C. FMC manual
• D. FMC exercise

Answer: (A)

When operating the Flight Management Computer with dual channels, you have two independent data paths that can provide redundancy. However, certain modes impose restrictions because having both channels active can create timing or data conflicts with how that mode handles mission-critical information.

In tactical mode, the system expects a single authoritative data source to drive navigation and displays used for mission execution. Allowing dual-channel operation could produce conflicting data or timing mismatches that might degrade situational awareness or impact tactical decisions. To prevent that risk, dual-channel operation is prohibited in tactical mode.

In the other modes, dual-channel operation is permitted because their data flow and display requirements don’t impose the same deterministic constraints as tactical mode.