The VAR NR caution on the CAD and MAN pushbutton illuminate in flight if the engines experience a torque split that exceeds what percent?

• A. 10
• B. 15
• C. 20
• D. 25

Answer: (B)

Torque split is the difference in torque output between the engines. When that imbalance becomes significant, warning systems alert the crew to prevent handling issues, increased wear, or stress on the drivetrain. The VAR NR caution for the CAD and MAN pushbuttons lights up in flight when the torque split crosses a specific threshold, signaling that the engines are not producing power evenly.

The threshold chosen—fifteen percent—strikes a balance: it’s low enough to catch meaningful imbalances quickly but high enough to avoid nuisance alerts from normal, small fluctuations. A lower threshold like ten percent would be too sensitive, while higher thresholds such as twenty or twenty-five percent could let a harmful imbalance go unchecked for longer. Hence, fifteen percent is the best, and aligns with the given answer.