none of the prop planes I flew had feathered props spin by the wind, ok, really,really slow, but not at high RPM
If the airplanes you mention were reciprocating-engine-equipped….the props would Not Spin….due to piston-compressions.
Fooling-around…on ferry flights…or taking the machine back ”home” after maintenance…. it was a (unauthorized) frivolous demonstration / action to feather Both Props on a King-Air while in-flight.
The free-wheeling props would spin very-slowly… likely not due to relative-wind…but most likely the result of powerplant-design…. The PT-6 engine was a reverse-flow turbine, in which the gas-generator produced hot-exhaust gas, purely for the purpose of ”blowing” it against a free-wheeling turbine geared to a feathering propeller.
(In fact, in arctic conditions it was not unheard-of for a person to actually Hold the prop stationary while the engine was started… the “horse-holder” (that‘s My Personal little “joke” in-reference to old cavalry-practice)… would then step-away After the engine was started. This little exercise was to allow the turbines to reach operating temperatures prior to allowing the prop power-turbine-to-combustion liner clearances to stabilize.) I don’ t believe that was actually necessary… or called-for by the mfr’r…but it was not an uncommon practice in -0 temps by some operators.)
