Originally Posted by
Brian Abraham
It's model dependant. The old 200 model King Airs with the three blade propellers came from the factory with auto feather as an option. From what I was told. It wasn't "cool " or "real men feather there own props". So initially the system was slow to be accepted to the flying population. Still today many older 200's are flying around with no autofeather fitted.
When Beechcraft built the B200 fitted with the new 4 blade Raisbeck props during the certification they discovered that the Vmca increased from 91KIAS to 108KIAS with a windmilling propellor. So a failed autofeather system on the 4 blade versions is a "no go" item and no provision is made in the MEL for you to dispatch with out auto feather.
From a Raisbeck King Air manual
AUTO FEATHERING SYSTEMS:
The Beech Propeller Autofeathering System must be installed, operational, and armed for takeoff, climb and approach.
CAUTION
With one-engine either at idle or inoperative, flaps up and propeller windmilling, VMCA may be as high as 108 KIAS.
As far as I remember, we had the 4 blade quiet turbofan propellers on our King Air 100 and no autofeather. No engine fire extinguishers either.