Pawnee 235 vs 260

We will be purchasing an additional PA25 for our club, and like many other facilities noise is becoming a bigger issue. Our current Pawnee has a 235 HP motor which has had the 250 HP STC (domed pistons) with a fixed pitch prop. The STC has performed well with far better climb performance when towing heavy glass 2-seaters. My question is whether a 260 HP Pawnee with a constant speed prop is louder that the 235 fixed pitch prop? I have heard this rumor, but have never been able to verify it.

Any and all input is welcome.

Skip Guimond

On Monday, November 14, 2016 at 2:03:03 PM UTC-5, wrote:
We will be purchasing an additional PA25 for our club, and like many other facilities noise is becoming a bigger issue. Our current Pawnee has a 235 HP motor which has had the 250 HP STC (domed pistons) with a fixed pitch prop. The STC has performed well with far better climb performance when towing heavy glass 2-seaters. My question is whether a 260 HP Pawnee with a constant speed prop is louder that the 235 fixed pitch prop? I have heard this rumor, but have never been able to verify it.

Any and all input is welcome.

Skip Guimond

The constant speed prop will allow a higher RPM which gets you more horse power and also better acceleration due to low pitch. The higher RPM means higher tip speed on the prop which is where the big noise comes from.
UH

YES! The 260 Pawnee with constant speed prop is ear shattering. When I
towed with it I always reduced prop RPM just after liftoff and, after
glider release, I reduced to the bottom of the green arc, about 2,200
RPM as I recall. I towed with a 235 Pawnee at Black Forest, about
1,000' higher than Moriarty, and it towed just fine. I also towed with
it at some 8,500' airports without difficulty.

On 11/14/2016 12:03 PM, wrote:
We will be purchasing an additional PA25 for our club, and like many other facilities noise is becoming a bigger issue. Our current Pawnee has a 235 HP motor which has had the 250 HP STC (domed pistons) with a fixed pitch prop. The STC has performed well with far better climb performance when towing heavy glass 2-seaters. My question is whether a 260 HP Pawnee with a constant speed prop is louder that the 235 fixed pitch prop? I have heard this rumor, but have never been able to verify it.

Any and all input is welcome.

Skip Guimond

--
Dan, 5J

On Monday, November 14, 2016 at 6:17:20 PM UTC-6, Dan Marotta wrote:
YES! The 260 Pawnee with constant speed prop is ear shattering. When I
towed with it I always reduced prop RPM just after liftoff and, after
glider release, I reduced to the bottom of the green arc, about 2,200
RPM as I recall. I towed with a 235 Pawnee at Black Forest, about
1,000' higher than Moriarty, and it towed just fine. I also towed with
it at some 8,500' airports without difficulty.

On 11/14/2016 12:03 PM, wrote:
We will be purchasing an additional PA25 for our club, and like many other facilities noise is becoming a bigger issue. Our current Pawnee has a 235 HP motor which has had the 250 HP STC (domed pistons) with a fixed pitch prop. The STC has performed well with far better climb performance when towing heavy glass 2-seaters. My question is whether a 260 HP Pawnee with a constant speed prop is louder that the 235 fixed pitch prop? I have heard this rumor, but have never been able to verify it.

Any and all input is welcome.

Skip Guimond

--
Dan, 5J

That Pawnee sounds like the trumpets of Jericho, loudest tow plane I've ever been around. If you want to **** off all your neighbors, get one.

I have seen a four bladed composite prop on a Pawnee. That Pawnee was pretty quiet and was used at a high altitude airport.


On Monday, November 14, 2016 at 5:49:26 PM UTC-8, wrote:
On Monday, November 14, 2016 at 6:17:20 PM UTC-6, Dan Marotta wrote:
YES! The 260 Pawnee with constant speed prop is ear shattering. When I

We have a 260 Pawnee "85P" with a constant speed prop. At max rpm on takeoff the sound rivals the aeroshell aerobatic team with their T6's. We reduce the prop rpm to 2600 climbing thru 100ft agl for noise concerns. After release we bring the prop back to 2500 rpm for the decent.

At contests if noise isn't a concern we leave the prop at max rpm for tow and decent. A 260 Pawnee with a constant speed prop is hard to beat for max launches per hour.

Operating cost is much higher with the constant speed prop. That needs to be considered in a club.

Franklin
Citrus Soaring

On Monday, November 14, 2016 at 7:54:51 PM UTC-7, Jonathan St. Cloud wrote:
I have seen a four bladed composite prop on a Pawnee. That Pawnee was pretty quiet and was used at a high altitude airport.


On Monday, November 14, 2016 at 5:49:26 PM UTC-8, wrote:
On Monday, November 14, 2016 at 6:17:20 PM UTC-6, Dan Marotta wrote:
YES! The 260 Pawnee with constant speed prop is ear shattering. When I

I think all of the Pawnees operating at Boulder may have 4 bladed props and mufflers as a noise concession. Mile High Gliding has the US STC for the Hoffman HO4/27BHM-185. Pretty sure it's wooden/composite construction.

Frank Whiteley

On Tuesday, November 15, 2016 at 3:54:51 AM UTC+1, Jonathan St. Cloud wrote:
I have seen a four bladed composite prop on a Pawnee. That Pawnee was pretty quiet and was used at a high altitude airport.



Almost all Pawnees in Sweden uses 4-blades props. Significant less noise and longer towing times but not significant longer.

On Monday, November 14, 2016 at 2:03:03 PM UTC-5, wrote:
We will be purchasing an additional PA25 for our club,. .

Hey, Skip . . we upgraded from the 235 to the 260 several years ago and, at the same time, installed the Hoffman 4-blade prop as a concession to noise complaints. Works like a charm, towing loaded two-place ships off a paved 3000'runway, field elevation 700', occasional density altitudes of 2500' or so.

Jim Kellett, Resident Curmudgeon

I object to all the criticism

The 260hp Pawnee can easily be made to pur like a little kitten.
We have one for sale

http://glidersource.com/cgi-bin/post.cgi?id=869

This particular Pawnee is made to be quiet and goes like a charm.
Hoffmann 4 bladed constant speed prop and muffler does the trick.

Feel free to be in touch