[TomVal]

I recently noted two ¼ inch hairline cracks on my Sensenich wood propeller Model W62HJ46G. The cracks are on opposite blades. One crack runs perpendicular to the trailing edge and the other runs perpendicular to the leading edge. Neither crack is radiating from a nick in the bIade. The prop has 87 hours on it. I spoke with Charlie at Sensenich and plan to send the prop in for inspection.

I noted that Sensenich offers several ground adjustable props for the Jabiru 2200 & 3300 engines. Their website states that vibration testing has only been conducted on the 80 hp engine. They also have ground adjustable models available for the 85-120 hp engines. If vibration testing has been completed on those models, I may be interested in upgrading the prop.

http://www.sensenich.com/products/item/137

Wrt to Op Limitations, would an upgrade to a ground adjustable prop from fixed pitch constitute a major modification???

The ground adjustable is heavier. The Jabiru cowl is longer than the Rotax cowl. I will also have to consider the impact on Wt & Balance before making a final decision.

 

[Mel]

Wrt to Op Limitations, would an upgrade to a ground adjustable prop from fixed pitch constitute a major modification???

The ground adjustable is heavier. The Jabiru cowl is longer than the Rotax cowl. I will also have to consider the impact on Wt & Balance before making a final decision.

Upgrade to a ground adjustable prop does constitute a major change, but you can make that change yourself. Paragraph (19) of your operating limitations tells you how to do it. Basically a logbook entry and back into phase I for at least 5 hrs.
You would only have to submit a new 8130-6 if you changed to a "controllable" propeller. Controllable propeller, in this case, means "cockpit controllable".

 

[TomVal]

Upgrade to a ground adjustable prop does constitute a major change, but you can make that change yourself. Paragraph (19) of your operating limitations tells you how to do it. Basically a logbook entry and back into phase I for at least 5 hrs.
You would only have to submit a new 8130-6 if you changed to a "controllable" propeller. Controllable propeller, in this case, means "cockpit controllable".

Thanks Mel. I am the second owner of this aircraft. In order to do the 5 hr phase I, I would need my op limits to designate a practice area in my local area. I had to go through this dance with the FAA with my -8 as a second owner in order to open the aerobatic window. The FSDO office initially wanted me to put the aircraft back into a 40 hour phase I just for the aerobatic qualification. I gently persuaded the Fed to just allow me a 5 hr flyoff window and he reluctantly agreed. If I have to go through this dance again, I think I'll on pass on the ground adjustable and just fly where there is no rain.

 

[Mel]

You should be able to have your op lims amended without an inspection just to change your flight test area. After that you can do everything yourself.

 

[TomVal]

You should be able to have your op lims amended without an inspection just to change your flight test area. After that you can do everything yourself.

I may have to find a DAR willing to amend the op limits. I will be out of town for several months so I have some time to work this out.

Once again, thanks for your input.

 

[RVTrumpet]

Just out of curiosity, did you balance the fixed pitch propeller during the 87 hours of operation?

 

[TomVal]

Just out of curiosity, did you balance the fixed pitch propeller during the 87 hours of operation?

No, the prop had not been balanced. Ironically, that and other items was on the agenda to be completed when we return to SC in August. As second owner, I've only flown 7 of the 87 hours on airplane.

 

[TomVal]

Jabiru - Ground Adjustable Prop

I’ve located a DAR in SC that is willing to work with me on upgrading to a ground adjustable prop. My limitation at the moment is that I am 2500 miles away from my RV-12 paperwork. I’ll have to confirm that my op lims permit the change and that the wt & balance will work out. The increase in wt should be okay however the affect on C.G. (non-standard longer cowl) may be uncertain.

Just got off the phone with Charlie at Sensenich. Wrt vibration testing on the Jabiru 2200 their website states the following:

Our 2 Blade Jabiru 2200 propeller is suitable for use on the 80HP Jabiru engine. It has currently not been vibration analyzed for use on any other direct drive engine.

Charlie stated that this prop would also work on the Jabiru 2200 85HP engine. Delivery time for the ground adjustable prop would be 3 weeks.

 

[TomVal]

Well, I got lazy. I decided to forego ordering a new ground adjustable prop and to just send my existing prop in for repair.

My friends pulled the prop and sent it in to Sensenich today. I also spoke with Charlie at Sensenich again. He said the turn-a-round time for my prop would be 2 to 2 1/2 weeks. If I ordered a new ground adjustable, it would take 8 weeks. After OSH orders, it could take even longer.

My sorrows...

I have submitted to only flying in a precipitation free environment.

No one will invite me to be part of a group trip.

I can no longer complain about not being able to fly in the rain.

Feel free to add to the list.

 

[txaviator]

The only thing I'd add, is that your plane should go with you to CA, the next time you'll go back

 

[TomVal]

The only thing I'd add, is that your plane should go with you to CA, the next time you'll go back

Yes...I think about it every time we are out west. But the tranquil allure of peaceful SC draws me...examples follow:

Flying San Diego VFR corridor...beautiful, head on perpetual swivel, playing dodge ball with other traffic...

Flying Charleston...beautiful, eating grapes, looking for naked beach goers, adoring city view...

 

[NASA515]

Where's the Bell and Whistle?

Bob Bogash
N737G

 

[Alschief]

Propeller Issues

We have a 107Hp UL Power 260is with a 64" Sensenich ground adjustable propeller.
We would like to go to a 60" 2 Blade Prop. Both Sensenich and Warp are concerned with these direct drive engines having issues with certain length propellers.
There have been some documented failures.
My advice is to follow what ever the manufactures suggest.

 

[TomVal]

We have a 107Hp UL Power 260is with a 64" Sensenich ground adjustable propeller.
We would like to go to a 60" 2 Blade Prop. Both Sensenich and Warp are concerned with these direct drive engines having issues with certain length propellers.
There have been some documented failures.
My advice is to follow what ever the manufactures suggest.

To add to your comments...

For the Jabiru 2200, the manual states that any "wood" prop made by a reputable manufacturer is acceptable as long as the prop diameter is no greater than 68" and the pitch is between 30-48".

Although Sensenich states they have a ground adjustable prop available for the 2200, vibration testing has only been performed on the 80 hp engine. Jabiru states the following:

To safely use a propeller made of metal or composite material a crankshaft vibration resonance survey as to be conducted to ensure that there are no damaging vibrations

Jabiru presently only recommends one ground adjustable prop. That prop is manufactured by Scimitar (model 4A482U0D). This prop is good for Jabiru 2200 variants up to 85 hp.

Although Charlie at Sensenich stated that their ground adjustable was also good for the 85 hp, without documentation to that effect, and the fact that I would have to obtain a new set of OP Lims to make the change, I elected to KISS and stay with my 62" diameter, 46" pitch wood prop...and just continue to avoid the rain.

BTW, when I was visiting at Jabiru USA, I was shown an engine that had failed due to an improper engine/prop combination. During a rapid power reduction the propeller moment of inertia put enough load on the engine to shear the crankshaft.

 

[TomVal]

Where's the Bell and Whistle?

Bob Bogash
N737G

Bob,

If your ever heard the sound of a Kinner, you don't need a bell and whistle! The engine has a very unique sound.

 

[ArlingtonRV]

I flew one of those (PT-22) out of Oceanside, CA many moons ago. Great fun.

 

[TomVal]

I flew one of those (PT-22) out of Oceanside, CA many moons ago. Great fun.

Do you recall the name of the owner?

I sold my -22 in 2002. It is now in the N.Y. area.

 

[ccsmith51]

.

I think I've figured out that the yellow cap is for oil, and the red cap for fuel. Is that right?

But what is that big thing sticking up in front on the cowl center line, aft of the fuel gauge?

 

[TomVal]

I think I've figured out that the yellow cap is for oil, and the red cap for fuel. Is that right?

But what is that big thing sticking up in front on the cowl center line, aft of the fuel gauge?

Yes...red is fuel, yellow is oil...never let the line boy top you off.

The stove pipe looking thing was part of the carburetor heat system. Fresh air through the stove pipe would mix with heated air in the shroud from the exhaust system.

The green post is called a "Rollover Mast"...an early Ralph Nader enhancement.

It was also used as a lift point for the fuselage. A special fitting would be inserted on the top of the mast for a hoist. There were many training accidents in the PT-22. It was aptly named the "Cadet Killer".

 

[TomVal]

Got word from Sensenich yesterday that my prop had only cosmetic damage to the paint. That was my suspicion also but I wanted a qualified set of eyes to take a look. Sensenich is going to refinish and balance the prop ($200). I should have the prop back in about 3 weeks.

 

[willy057]

I just have a comment about the Jabiru 2200, and the prop problems. In the Titan community, there were quite a few folks running the Jabiru. When the engine first came out, prop cracks were common, no matter what prop. Since the engine is direct drive and turns 3300 rpm., the tips were turning faster than the sound barrier, and that was the cause of the prop cracks. If you would look at most of the planes running the Jabiru, they run a short.....real short prop with a lot of pitch.

 

[TomVal]

I just have a comment about the Jabiru 2200, and the prop problems. In the Titan community, there were quite a few folks running the Jabiru. When the engine first came out, prop cracks were common, no matter what prop. Since the engine is direct drive and turns 3300 rpm., the tips were turning faster than the sound barrier, and that was the cause of the prop cracks. If you would look at most of the planes running the Jabiru, they run a short.....real short prop with a lot of pitch.

Good input. I run a 62" prop. My prop is pitched high at 46 with a Jabiru limit of 48. The normal cruise RPM is 2700 - 2950. At WOT at S.L. I hit 3150 RPM. Thanks for the heads-up. I'll report back if I observe any problems with the prop.

I assume the Titans were running 3 bladed props with shorter diameters.

 

[willy057]

That is correct. I have seen several Sonix (sp) running the Jabiru with a 2 blade, and it was really short as well.