On Wed, November 26, 2008 4:16 pm, Lynn Matteson wrote:
>
> I'm a rookie...why would you have to adjust the pitch of the prop
> during takeoff? Seems like you'd set it for takeoff and go, then
> change it to cruise when you get there....no?
These props aren't constant speed props that you probably used in your certified
experience. So, you don't control them the same way.
With a cockpit adjustable (not-constant speed) prop, at run-up, you set the prop
to
maximum horsepower rpm, WOT. As soon as you begin to roll, you're going to either
have
to increase the pitch or pull back the power to control the rpm. Best practice
is
normally to keep adding pitch as required until until you reach best angle or best
rate speed. When you reach traffic pattern altitude then you reduce power as you
would
in a fixed pitch propeller configuration. At this point you might need to adjust
the
pitch again for best economy.
--
Paul A. Franz, P.E.
PAF Consulting Engineers
Office 425.440.9505
Cell 425.241.1618
