Which system must be in manual mode for the engine trim 4-way beeper to be active?

• A. VARTOMS
• B. FCS
• C. EIS
• D. IAS

Answer: (A)

The audible signal for engine trim is tied to manual trim control, so it will only be active when the system that handles engine trim is in manual mode. That system is VARTOMS, which directly interprets your trim inputs and drives the engine trim accordingly. When VARTOMS is in manual mode, your 4-way trim commands are being applied by hand, and the beeper serves as a real-time alert that trim is actively changing.

The other systems listed don’t control engine trim in the same hands-on way. The flight control system (FCS) governs flight surfaces and autopilot functions, the engine information system (EIS) provides data but doesn’t drive trim, and the indicated airspeed system (IAS) relates to speed data. None of these trigger the engine-trim beeper in the same manner as manual trim via VARTOMS, so the beeper remains silent when they’re active.