Originally Posted by
Aucky
..I was looking at it from a stuck/fixed governor perspective where the first thing you will see is a TQ mismatch caused by lever inputs...
With a digital engine control, such as in the S76C++, the first thing you will see is the blue DECU capsule light come on. This will remove power to the stepper motor in the fuel control unit resulting in a fixed fuel flow for that engine irrespective of collective position. Changing the collective position will now cause a torque mismatch. Although there could be a malfunction causing the stepper motor to go full open and things can then get exciting quickly, particularly if the collective position had a low power demand when the malfunction occurred.
If we had a very competent pilot in the simulator and he wanted a challenge to fill in some idle time, double DECU failure did the trick, one just after the other. i.e. both engines in manual fuel control. That malfunction would never happen for real, but it is covered in the RFM. It's a good challenge for the pilot to find a way to land without over spinning something.