Teldorserious,
since I am unable to upload attachments (I am waiting suggestions from the Administrator)
I copy herebelow the relevant parts of the AFM (you can anyway download it from different websites)
Rev.0 Issued 21-oct-2005
Pag.2-2
Minimum control speed
Autofeather system operative 100 KIAS
Propeller windmilling 128 KIAS
Engine failure in flight below Vmca
Pag 3-6
1 Power lever (operating engine) Reduce power to maintain control
2 Airspeed Increase above VMCa
3 Power Lever (Operating engine) AS REQUIRED
4 Inoperative engine : SECURE as per ENGINE SECURING Procedure
Limitations pag 2-9
Autofeather system limits
WARNING : no take off is authorized with AF inoperative
1 The AF system must be pre flight checked operational prior to take off
2 The AF system must be used for TO and Landing operations
The P180 is not allowed to TO with AF inoperative ; besides, the single-engine climb performance , and all other single-engine performances, are all based on a feathered propeller.
Different things are the cause of the high VMCa (windmilling) : among them, the fact that the tail arm is ‘short’, and this impact not only on the rudder authority, but also on the tail damping during a dynamic engine failure, where the yaw rate has been considered extremely high .
Daniel