Generally speaking you should not utilize the autopilot when flying any light twin single engine. That said if you are single pilot and, it may not be a bad idea to engage it momentarily to maintain a safe attitude while completing something like an approach briefing. I used a KFC 225 momentarily on my Multi IFR training, but found I did not need it. In the sim where you are using a mouse and keyboard to look around and complete actions I can imagine it would be very helpful.
Extra Blurb:
When experiencing an engine failure you are to conduct the appropriate emergency checklist for the phase of flight from memory in a timely manner and then declare an emergency.
My flow for the turbine duke would look like this:
Disengage autopilot
Maintain control (Maintain ALT if able and pitch up to compensate for power loss ensuring your speed does not fall below the blue line speed)
If Fire: extinguish and continue below next two items
Identify the failed engine visually with rpm gauge
verify (utilizing the throttle to ensure the identified engine's gauges are unresponsive to inputs)
Inop Eng Power Lever Idle
Inop Eng Propeller Feather
Inop Eng Condition Lever Cutoff
Op Eng Propeller Full Forward (Not in Checklist but should be)
Op Eng Power Lever 1200 FT-LBS if level; 1260 FT-LBS if climb is required
Establish a safe flight attitude (very important and why you should not utilize A/P):
Hold dead engine wing up with 3-5 degree bank and apply appropriate rudder to keep the turn coordinator ball half out towards the dead engine (consider using rudder trim if extended flight is required on one engine)
Continue rest of checklist items utilizing emergency checklist and declare emergency with ATS
Everything before last bullet point should be able to be executed within 15 seconds of the engine failing if you are proficient. In a piston engine aircraft in cruise phase of flight you would also need to demonstrate executing troubleshooting items from memory as well before cleaning up and feathering the failed engine if the failure was not obviously catastrophic.
