Sensenich Ground Adjustable Prop

[Steve Pierce]

No idea, waiting on the FAA. Will updater this thread as things move along.

[BritishCubBloke]

No idea, waiting on the FAA. Will updater this thread as things move along.

Thanks. Presumably Catto has given up on the STC process now?

[MoJo]

No idea, waiting on the FAA. Will updater this thread as things move along.

Last I heard.

Flight testing not quite complete due to wreck. ( When will this start again?)

Things should happen fast after testing (fed’s slow down complete.)

Props are being built, and should be sent out fast after the rubber stamp.

[Utah-Jay]

….
Props are being built, and should be sent out fast after the rubber stamp.

Don’t bet on that, mine was supposed to ship Feb 28th, they are a least a month behind as mine might ship in the next couple of weeks. I think the experimental market is keeping them busy at the moment

edited to add: it’s shipping today

[Steve Pierce]

Cooling and dive tests complete. Have to do performance test now, take-off, climb and landing. After that data is compiled they put the noise test criteria together but the FAA noise test engineer has ass chap with the noise test DER. The DER has an amazing reputation around here and works with McCauley and Hartzell but someone has a burr up their butt. Sensenich does not have enough production to keep up with demand. Can't hire enough people. I am going to Sensenich the week after next to tour the plant. Will report back.

[MoJo]

The DER has an amazing reputation.

and therein lies the the problem. Being married to someone that has worked for both state and federal government for nearly 30 yrs, I can tell you that Government competence is not allowed, seriously discouraged, and will always be punished.

[BC12D-4-85]

Local experimental PA-18-160 will get back to back Borer/Sensenich adjustable starting this weekend. Prop arrived this week. Will report tho not my plane. It's on Aero skis so the pull in deep snow will be interesting.

Edit: Will also try to get him to do climb rate and cruise speed vs fuel flow and airspeed at his preferred rpm.

Gary

[See_ya]

3 months and so far so good. Holding up better than the Pawnee I was using before.

[BC12D-4-85]

Here's the initial test results from 3/26/22 in Fairbanks for the 82" Sensenich. It was +40F at ~450 msl with wind less than 5 mph. Plane is EXP PA-18-160 w/Dakota Cub wings, long gear, and Thrustline engine mount. Owner is pleased. So far better performance compared with a Catto 82/40 and Borer 82/42.

Capt. Eddie at the stick

[BC12D-4-85]

^^^^There will be more testing in the coming weeks as the owner explores the prop's performance envelope. Things like cruise performance vs fuel flow and rpm. One thing I noted while he was testing was it cranked and started quickly...same for shutdown. It spun up fast if power was needed in flight. Weight of about 19# compared with metal Borer at 33# we had just removed.

Edit: One thing I noted as an observer was the sound signature on takeoff. At the "0" pin full flat pitch setting it sounded smooth during takeoff and pulled good like the Borer 82/42. At "2 and 4" pins it initially sounded like ducks farting in shallow water...typical for some blade cavitation common to getting on step with a floatplane until it starts really pulling.

Blade track was checked to be within 1/8" and it reportedly ran very smooth with no rpm-related rough spots. It truly took 5 minutes to change the prop pitch with the supplied variable diameter setting pins. The supplied Nord-Lock washers under the bolt heads make it easy and secure. We checked the torque of the bolts after an initial run and after every pitch change. They held true after a few flights.

The only concern now may be to add a cover plate over the adjusting pin holes to exclude water and debris. There's threaded holes next to them to attach a cover (or just duct tape ) I was impressed with the quality of the setup and would own one. They make an EXP for my Taylorcraft.....hmmmm.

Gary

[BC12D-4-85]

Here's a final test sheet for Post #169 above. It includes a test flight with adjustment pin #5 of the six available (0 through 5; 0 is the flattest pitch). Capt. Eddie said #5 still performed well on takeoff but was best for cruising. Next testing will be with a loaded airplane. Current fights were pilot and half or less fuel in the Dakota tanks.

Gary

[bjenkins]

This was my Cessna that was able to get the field approval. The local FSDO was great to work with and forwarded it to the Chicago ACO engineers. So no DER was involved, it was all FAA. I just completed the O-360 engine swap, so still flying with the prop in the middle pitch setting but the performance is incredible.

[DJ]

Wow what a Bird! What does it weigh?

Sent from my SM-G965U1 using SuperCub.Org mobile app

[KevinJ]

Looks like a ripper!

[bjenkins]

We put it on scales after the engine conversion and it weighed 1302lbs.

[KevinJ]

Stripped interior? Any other pics? Might be a unicorn

[bjenkins]

I have a partial interior, all of the seats, door panels, and front side panels. With the O-360 and light weight she climbs very well. 1/2 tanks and me, it’s easy to see 1700-1800fpm at 75mph.

[Farmboy]

And then comes Brian, showing off the nicest 172 in the states, but it identifies as a 180/170 to the casual observer.

If only he can keep it out of the brush he flys in.
pb

[bjenkins]

Thanks Peter! Are you questioning how it identifies?!? 😆

Since I finished the install I have gotten overwhelmed with messages about it. I hope it opens up more opportunities for others to do the same.

[jrussl]

Sent from my iPhone using SuperCub.Org mobile app

[Farmboy]

LOL Jeff!

[jrussl]

I see that Sensenich is now starting to market these props.

https://www.avweb.com/aviation-news/...t-ga-aircraft/

Any more info on the certification for the O-320 variants?

Jeff

[Steve Pierce]

They just received the Type Certificate on the prop. This is a big deal because now it is easier for others to obtain other STC's on different aircraft. As far as the STC on the 150/160 hp Super Cub is concerned it is in a quagmire between FAA noise test engineers and their pother engineers as to the testing procedures. We are finishing up repairs on the aircraft the FAA ran off the runway this week. I can say this has been a frustrating experience on so many levels. The good thing is I have learned a ton and the Sensenich engineers are great to work with and have taught me a lot about props. Just installed an STC'd 180 hp prop on an Amphib Super Cub on Tuesday, saved 24.5 lbs, leading edge won't erode away like aluminum and the pilot tells me it is getting off the water quicker as well.

[hotrod180]

..... We are finishing up repairs on the aircraft the FAA ran off the runway this week......

Are they gonna make their own pilot take a 709 check ride?

[BritishCubBloke]

Any news yet?

[Steve Pierce]

No, I will keep this thread current as we proceed.

[KevinJ]

Good props. Worth the wait.

[TxAgfisher]

Looking forward to hearing more - these McCatto lengths/pitches are all over the place so I think it would be hard to get an apples to apples test short of measuring thrust output on the same powerplant for all the combinations.

[KevinJ]

Seat of the pants, after going back and forth from an 84” Catto to the GA, says the GA pulls as hard out of the hole but is considerably faster even on the finest pitch. Also glass smooth if care is taken keeping the pitch and clamshell halves lined up.

One area the Catto may win on is the strength of their nickel leading edge. The stainless leading edge on my GA appears softer or maybe it’s just not as lucky as my Cattos

Maybe Ford will chime in. He’s had a chance to play swap-a-prop on both wheels and floats.

[RaisedByWolves]

Seat of the pants, after going back and forth from an 84” Catto to the GA, says the GA pulls as hard out of the hole but is considerably faster even on the finest pitch. Also glass smooth if care is taken keeping the pitch and clamshell halves lined up.

One area the Catto may win on is the strength of their nickel leading edge. The stainless leading edge on my GA appears softer or maybe it’s just not as lucky as my Cattos

Maybe Ford will chime in. He’s had a chance to play swap-a-prop on both wheels and floats.

You almost didn’t get it back. It’s really impressive that everything is the same except the pitch, how much cruise you will get.
On the climb pitch (0) I got 2560 static, 2550 indicates 85mph

On the cruise pitch (5) 2350 static 105mph cruise. There’s a noticeable difference in takeoff performance.


Sent from my iPhone using Tapatalk

[Steve Pierce]

A little more info on setting prop pitch and torqueing.
Steve,

The most common source of vibration after repitching a propeller is incorrect blade angle.The clamp gap on each side of the blades should be equal prior to setting pitch. A visual check is generally sufficient, but feeler gauges or similar tools may be used if desired.

Hand-tighten the clamp and through mount bolts until turning the blades requires some effort to counteract the friction. The blades should be snug but movable with moderate effort. Ensure the clamp gap is kept equal during this process.


After setting the pitch for a blade, tighten the clamp bolts(roughly 1/4 to 1/2 turn) around that blade to ensure it does not change pitch while adjusting the remaining blade. Ensure the clamp gap is kept equal during this process.


Torque the 4 mount bolts incrementally to full torque. Applying full torque to 1 bolt prior to tensioning others can rock the mount cover and change pitch of the blades(one blade goes up and one blade goes down).


Torque the 4 clamp bolts incrementally to full torque. Then re-check all bolts. It is common for a clamp bolt to turn another 1/8-1/4 turn after torquing the clamp bolts.


Recheck that clamp gap is approximately equal. You can also use the next pin size down to check that neither blade de-pitched during installation.

[frequent_flyer]

Who does FAA authorize to adjust the prop pitch on an aircraft with a standard airworthiness certificate? What, if any, log entries are required?

Just curious because the closest I can legally get to the propeller on my PA-28 is to check/replace the safety wire. I'm not considered competent to remove/replace/torque the bolts that secure its fixed pitch prop.

[gntw]

A little more info on setting prop pitch and torqueing.
Steve,

The most common source of vibration after repitching a propeller is incorrect blade angle.The clamp gap on each side of the blades should be equal prior to setting pitch. A visual check is generally sufficient, but feeler gauges or similar tools may be used if desired.

Hand-tighten the clamp and through mount bolts until turning the blades requires some effort to counteract the friction. The blades should be snug but movable with moderate effort. Ensure the clamp gap is kept equal during this process.


After setting the pitch for a blade, tighten the clamp bolts(roughly 1/4 to 1/2 turn) around that blade to ensure it does not change pitch while adjusting the remaining blade. Ensure the clamp gap is kept equal during this process.


Torque the 4 mount bolts incrementally to full torque. Applying full torque to 1 bolt prior to tensioning others can rock the mount cover and change pitch of the blades(one blade goes up and one blade goes down).


Torque the 4 clamp bolts incrementally to full torque. Then re-check all bolts. It is common for a clamp bolt to turn another 1/8-1/4 turn after torquing the clamp bolts.


Recheck that clamp gap is approximately equal. You can also use the next pin size down to check that neither blade de-pitched during installation.

thanks Steve will try this

[dgapilot]

Who does FAA authorize to adjust the prop pitch on an aircraft with a standard airworthiness certificate? What, if any, log entries are required?

Just curious because the closest I can legally get to the propeller on my PA-28 is to check/replace the safety wire. I'm not considered competent to remove/replace/torque the bolts that secure its fixed pitch prop.

Off the top of my head, unless the ICA that comes with the STC says otherwise - Given that adjusting ground adjustable props is not listed in 14 CFR 43 Appendix A under Preventive Maintenace or as a Major Repair, that would put it as a Minor Repair by the definition in 14 CFR 1.1. No matter who does it, 14 CFR 43.9 would require a maintenance record entry.

[Penguin]

Steve - any more info behind the curtain? I tore my leading edge on my Borer on my last flight. I'm not sure it's dressable. I might have to hold tight and wait for the STC to pop.