The engine trim 4-way beeper switch on the pilot's and co-pilot's collective is active only when which system is in manual mode?

• A. N1 control system
• B. N2 control system
• C. Hydraulic control
• D. VARTOMS (Variable Rotor Speed Torque Matching System)

Answer: (D)

The beeper for engine trim is linked to manual torque matching. In helicopters that use VARTOMS, rotor speed and engine torque are normally kept in balance automatically. The four-way beeper switch becomes active only when VARTOMS is set to manual mode, allowing the crew to manually trim engine torque without conflict with automated control. When VARTOMS is in automatic mode, the system handles torque matching by itself, so the manual trim beeper isn’t active. The other systems mentioned (N1 or N2 control, hydraulic control) don’t govern this manual torque-trim behavior, since they relate to engine spool speeds or hydraulic actuation rather than the manual torque-matching mode.