3-blade prop?

We were hoping that our prop would last until the city was done
repaving our horrible taxiways. There was no sense in replacing it
while we were literally picking up stone chips on every flight.

Well, on our first flight after getting back in our own hangar, with
our beautiful new taxiways (after fighting for 8 years to get them
resurfaced!), we picked up a nice thin sheen of oil on the windshield.

We've cleaned everything up, and plan on keeping a close eye on it, but
I know we're getting close to needing to do something with the prop --
it's past due in time.

We would either go with an overhaul, or now would be the time to
install a 3-blade prop, both for inproved smoothness of operation (the
Lyc O-540 ain't known for smoothness) and improved ground clearance (we
like grass strips).

Any input either way would be great. Anyone converted to the 3-blade
prop in the Pathfinder/Dakota/Cherokee Six line? Anything good or bad
to say would be helpful.

Thanks!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote:

We would either go with an overhaul, or now would be the time to
install a 3-blade prop, both for inproved smoothness of operation (the
Lyc O-540 ain't known for smoothness)

In the various Cessna forums I monitor, owners have reported mixed results
going to 3-blade. Some have complained of *more* vibration, though noise is
less. Something about the engine dynamic balancers, though there is
controversy about this.

Hartzell recommends replacing the lord mounts with this conversion,
according to one 210 owner who had it done.

What do the Piper owners say?

--
Dan
C172RG at BFM

Dan Luke wrote:
Hartzell recommends replacing the lord mounts with this conversion,
according to one 210 owner who had it done.

What do the Piper owners say?


You definately need to plan on replacing the mounts. Lord makes
a mount specific to the McCauley 3 blade installation and I believe
that the installation kits include these new Lord mounts.

Having recently installed a McCauley 3 blade on my PA24-250 I
can tell you it is smoother and has less vibration than the old
two blade. The climb is much better...I have to literally stomp
on the brakes during run-up or it will drag me onto the runway.

My cruise performance actually increased from 155 to 160 Kts.
This is probably due to the new APP cowling (and full length
nose gear doors) installed at the same time. For my installation
the MaC 3 blade was really the least expensive choice as the
the Hartzell alternatives (to eliminate the AD my prop had)
were more expensive. Besides... look how many ADs Hartzell keeps
coming up with.

Any input either way would be great. Anyone converted to the 3-blade
prop in the Pathfinder/Dakota/Cherokee Six line? Anything good or bad
to say would be helpful.

How much weight (useful load) and efficiency are you willing to donate
to the prop?

Compare two-blades to three-blades.

http://www.hartzellprop.com/index2.htm

http://www.mccauley.textron.com/home.html

Jay Honeck wrote:


Any input either way would be great. Anyone converted to the 3-blade
prop in the Pathfinder/Dakota/Cherokee Six line? Anything good or bad
to say would be helpful.


Can't vouch for the PA32's, but there's definitely an improvement on
the large engined Navions with the three blade (or in Ron Judy's case
the four blade). The only problem is they just don't sound like
Navions anymore. Of course, I have to stop maligning those
installations since I got mine.

I'd check what it does to your W&B though. I don't know what the
CG range is on the PA32, but I think the three blade is going to
move it forward.

"Jay Honeck" wrote:
We would either go with an overhaul, or now would be the time to
install a 3-blade prop, both for inproved smoothness of operation (the
Lyc O-540 ain't known for smoothness) and improved ground clearance (we
like grass strips).

One thing that may not be obvious is that the 3-blader will probably weigh
more. I think I remember looking up the paperwork on my club's Arrow (3
blades installed by a previous owner) and it was 11 pounds more.

The weight itself may not be a problem, but hanging out on the nose, it
makes a big difference in CG (which, depending on your CG now, may be a
good or a bad thing).

Jay Honeck wrote:

Any input either way would be great. Anyone converted to the 3-blade
prop in the Pathfinder/Dakota/Cherokee Six line? Anything good or bad
to say would be helpful.

Jay, sorry I cannot offer any specifics about your aircraft, but I can
share my decision when I was presented with the option of installing a
three-blade on my Bonanza a couple of years ago.

This was my list of pros and cons of going to a three-blade:

Pros:
- quieter
- better climb rate
- coolness factor

Cons:
- cost
- reduction of cruise speed by a few knots

I, too, recall reading about some who had problems with vibration after
upgrading.

In the end, I decided that the cost didn't justify the pros and the
marginal loss of cruise speed was not the direction I wanted to move after
stepping up from a C172.



--
Peter

: Pros:
: - quieter
: - better climb rate
: - coolness factor

- Shorter takeoff too, no?

: Cons:
: - cost
: - reduction of cruise speed by a few knots

I don't remember if you said you had a lightweight PM starter on your bird,
Jay. If not and you put one on, that would offset the increased weight on the nose
with a 3-bladed prop.

-Cory

--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

I don't remember if you said you had a lightweight PM starter on your bird,
Jay. If not and you put one on, that would offset the increased weight on the nose
with a 3-bladed prop.

Yeah, we've got the lightweight starter, so we're good there.

As far as any loss in useful load, I won't notice 11 pounds on 1460.
The W&B might be an issue though -- Atlas is already a bit nose-heavy.
Nothing a toolbox in the luggage compartment doesn't cure, though.
(And when we've got four on board, all is good.)

Anyone got any experience with CS props going bad? The oil on the
windshield was minimal, and there was only slight evidence of oil on
one blade. Is this something that could:

a) Stay the same over time
b) Get worse little by little
c) Let loose all at once

Also, can anyone recommend a good prop shop?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:
Anyone got any experience with CS props going bad? The oil on the
windshield was minimal, and there was only slight evidence of oil on
one blade. Is this something that could:

a) Stay the same over time
Yes
b) Get worse little by little
Yes, or even get better.
c) Let loose all at once
Probably not, but of course you should have it all
inspected by your A&P, or just take off the spinner
and have a look yourself to see if its even coming
from the prop/hub.

A small amount of oil on the windscreen now and
then does happen, especially when weather temp
changes a lot. And, it may not be coming from the
prop. You'd be suprised at just how such a very small
amount of oil can get slung around by the prop and
get on the windscreen.