Next step in the 175B, insurance companies are a pain! CS prop question

[Wayne]

Well, sent my info to the insurance, they got back to me, through one of
the other partners, and said they needed more information. They wanted to
know how many hours I had in a 175B, I said I had none, but shouldn't the
172 count? It's the same except for the CS prop. So I gave them what they
wanted, and they said that I was covered now for dual until I got 2 hours
and a sign off. Went and did that tonight, now I'll fax them a copy of the
signoff and away I go! I hope. I won't be suprised if they want something
else though.

Love the plane though, man what a difference from a 150. 15 years older
than what I was flying and so much nicer. I only wish it had a back window
so I could hold centerline better.

Still a little weired out about the CS prop though. Read what I could
find and it seems like everyone I talk to has a different opinion on what is
right and wrong. Some say climb at 24MP and 2400 RPM prop. Cruise at 23
squared. The tach has a red area marked and is noted that you shouldn't run
in that range for an extended period, it's around 1700-2000 RPM's I think.
What's up with that? Vibration? Harmonics? I was also told to use full prop
if under 100MPH or under 15MP. Can anyone enlighten me on this?

Wayne

[BTIZ]

> squared. The tach has a red area marked and is noted that you shouldn't
run
> in that range for an extended period, it's around 1700-2000 RPM's I think.
> What's up with that? Vibration? Harmonics? I was also told to use full
prop
> if under 100MPH or under 15MP. Can anyone enlighten me on this?
>
> Wayne

Yes, harmonics and vibrations, there are many aircraft that have similar
limitations, the C177 comes to mind, and also some 3 bladed Arrows.

Full Prop if under 100MPH? not sure about why that one.. but I'm sure the
idea of going to full prop (high RPM) when under 15in MP, you are most
likely below the "prop governing range" and want the best performance, if
your under 15in MP you are either "throttled back" for descent, or very high
MSL.

enjoy the plane..
BT

[Ron Natalie]

"Wayne" > wrote in message ...

> Still a little weired out about the CS prop though. Read what I could
> find and it seems like everyone I talk to has a different opinion on what is
> right and wrong. Some say climb at 24MP and 2400 RPM prop. Cruise at 23
> squared. The tach has a red area marked and is noted that you shouldn't run
> in that range for an extended period, it's around 1700-2000 RPM's I think.
> What's up with that? Vibration? Harmonics? I was also told to use full prop
> if under 100MPH or under 15MP. Can anyone enlighten me on this?

Get you to your POH. Do NOT listen to old wives tales especially when it
comes to geared engines. Running the GO-300 at incorrectly l low RPM
settings is one of the reason they got a bad name.

[Ron Natalie]

"BTIZ" > wrote in message news:sxh0b.5319$Qy4.1728@fed1read05...

> Full Prop if under 100MPH? not sure about why that one.. but I'm sure the
> idea of going to full prop (high RPM) when under 15in MP, you are most
> likely below the "prop governing range" and want the best performance, if
> your under 15in MP you are either "throttled back" for descent, or very high

Bad idea in geared engines to run the prop forward in descents. There's always
a tiny amount of play in the gearbox. You don't want to spend a lot of time
with the prop driving the engine.

[Wayne]

This one's not geared, it was replaced with an O-360

"Ron Natalie" > wrote in message
. ..
>
> "BTIZ" > wrote in message
news:sxh0b.5319$Qy4.1728@fed1read05...
>
> > Full Prop if under 100MPH? not sure about why that one.. but I'm sure
the
> > idea of going to full prop (high RPM) when under 15in MP, you are most
> > likely below the "prop governing range" and want the best performance,
if
> > your under 15in MP you are either "throttled back" for descent, or very
high
>
> Bad idea in geared engines to run the prop forward in descents. There's
always
> a tiny amount of play in the gearbox. You don't want to spend a lot of
time
> with the prop driving the engine.
>
>

[Wayne]

Yeah as well and diving and running the engine rpm up from the dive. But
mine has an O-360, not the old O-300. The POH isn't so easy since it's a
mod. The 100MPH and 15MP came from an O-360 manual if I remember right.
Wayne
"Ron Natalie" > wrote in message
. ..
>
> "Wayne" > wrote in message
...
>
> > Still a little weired out about the CS prop though. Read what I
could
> > find and it seems like everyone I talk to has a different opinion on
what is
> > right and wrong. Some say climb at 24MP and 2400 RPM prop. Cruise at 23
> > squared. The tach has a red area marked and is noted that you shouldn't
run
> > in that range for an extended period, it's around 1700-2000 RPM's I
think.
> > What's up with that? Vibration? Harmonics? I was also told to use full
prop
> > if under 100MPH or under 15MP. Can anyone enlighten me on this?
>
> Get you to your POH. Do NOT listen to old wives tales especially when it
> comes to geared engines. Running the GO-300 at incorrectly l low RPM
> settings is one of the reason they got a bad name.
>
>

[[email protected]]

On 18-Aug-2003, "Wayne" > wrote:

> Still a little weired out about the CS prop though. Read what I could
> find and it seems like everyone I talk to has a different opinion on what
> is right and wrong. Some say climb at 24MP and 2400 RPM prop. Cruise at 23
> squared. The teach has a red area marked and is noted that you shouldn't
> run in that range for an extended period, it's around 1700-2000 RPM's I
> think.
> What's up with that? Vibration? Harmonics? I was also told to use full
> prop if under 100MPH or under 15MP. Can anyone enlighten me on this?


The STC covering the engine change should have included a supplement for the
POH (actually, it's probably an "Owner's Manual" on an old Cessna). This
supplement should include a new set of performance charts that allow you to
figure, among other things, percentage of power at given MP/RPM settings.
Which to use? Well, for TO and max performance climb the prop should be at
max RPM. The prop control should also be put full forward after you retard
the throttle to land. (Do it earlier in the pattern and the sudden increase
in engine speed will likely give a start to your passengers.)

For cruise, any recommended MP/RPM combination is fine. You may find that
the engine runs smoother at some settings than at others. Of course, you
should avoid RPM settings in the red arc, which may cause excessive
sympathetic vibrations.

You have probably already been instructed that, in making power changes that
involve both throttle and prop controls, you should pull back on the
throttle first (for reducing power) and push forward on the prop control
first (for increasing power).

-Elliott Drucker

[Ron Natalie]

"Wayne" > wrote in message ...
> This one's not geared, it was replaced with an O-360
>
Nevermind.