View Single Post
  #9  
Old August 16th 08, 03:08 AM posted to rec.aviation.owning,rec.aviation.piloting
BT
external usenet poster
 
Posts: 995
Default Adjustable Prop for a Cessna 150

Don't forget the CG change.. losing 14# on the nose is a lot.. you are going
to be tail heavy
BT

"Charles Talleyrand" wrote in message
...
On Aug 15, 3:10 pm, "Vaughn Simon"
wrote:
"Charles Talleyrand" wrote in message

...

Suppose I put this prop on my Cessna 150. It only weighs 9.5 pounds,
as compared to the Sensenich weight of 24 pounds. So I save 14.5 #.


But it will make a largish change in your CG. The fuel and passenger
load
for a 150 are both near the CG, so you might end up putting a few pounds
of
ballast in the tail to stay within the CG envelope. That would cost you
some of
the initial weight advantage.

Can anyone guess how this would effect my performance? How much
better climb and how much better cruise?


Nobody can answer that question until you specify a pitch. Any given
fixed
pitch prop will be optimized for climb (at the expense of cruise speed)
or
cruise (at the expense of takeoff and climb performance) or somewhere in
between.



Actually, one can assume that it will climb at least as well as the
standard climb prop, and cruise at least as well as the standard
cruise prop.

The difference between the cruise (normal) prop climb performance, and
the climb prop climb performance, will be available to cruise prop
users.

The difference between the climb prop cruise performance, and the
cruise prop cruise performance, will be available to climb prop users.

Anyone know these numbers?

Alternatively, there must be planes that have used both fixed and
constant-speed props. Anyone know the difference?