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RV-12 and RV-12iS Service Publication Updates dated October 6 2020

greghughespdx

Well Known Member
Advertiser
Every now and then things need to come in batches!

We’ve published a number of RV-12/12iS service/documentation updates to the Van's web site. They include some revised plans pages, two new service letters, one new service bulletin, one revised service bulletin, and a number of other key document revisions:

For the RV-12 with 912ULS engines, please refer to new Service Bulletin SB-00026 and related documentation updates (below) regarding retaining plates for carburetor springs on 912ULS engines. The SB requires inspection and installation of a new part at or before the next condition inspection, to prevent potential unacceptable spring wear on the carb throttle shaft. The RV-12 Maintenance Manual is the latest update, and as such applicable to all owners/operators of the original RV-12, of course.

  • RV-12 SB-00026 (new)
  • RV-12 SB 18-03-06 (revised to include reference and requirement to comply with SB-00026)
  • RV-12/12iS Section 49U
  • RV-12 Section 50
  • RV-12 Maintenance Manual (MM)

We have also published a service letter allowing the installation of finger-grip knobs RV-12 vent assembly, which can make it easier to open and close the air vents. Note that these have been available in new RV-12 kits for several months, and this document allows existing SLSA airplane owners/operators to install them and remain compliant.


We published updated RV-12iS documents and assembly instructions related to the use of the updated GTN 650xi IFR NAV/COM radio (often called the IFR Avionics package) and other related components. Note that these most recent FTS/PAP/MM/POH documents are, of course, applicable to all customers operating an RV-12iS.

  • RV-12iS Flight Test Supplement (FTS) (updated)
  • RV-12iS Production Acceptance Procedure (PAP) (updated)
  • RV-12iS Maintenance Manual (MM) (updated)
  • RV-12iS Pilot Operating Handbook (POH) (updated)
  • RV-12iS Sections 42PiS, 42MiS, 53BiS

Service Letter SL-00024 was published along with related updates to RV-12/12iS Maintenance Manual and other connected plans pages/documents, specifying the need and requirement to perform a dynamic balance of the ground-adjustable pitch propeller at the next condition inspection or sooner, and any time the prop pitch is changed.

  • SL-00024
  • RV-12iS Production Acceptance Procedure (PAP) (updated)
  • RV-12 Production Acceptance Procedure (PAP) (updated)

Updates have been made to the RV-12/12iS Plans Sections to ensure excess thread-locking fluid is not used when addressing trim servo issues/maintenance

  • RV-12iS/RV-12 common Section 11iS-U

Plans pages changes have been published for the RV-12iS related to our change from Garmin's GMC 307 to the GMC 507 Autopilot Control Module (new part and design). Related wire harness drawing updates were also recently published on our Suport Downloads page.

 
Service Letter SL-00024 was published along with related updates to RV-12/12iS Maintenance Manual and other connected plans pages/documents, specifying the need and requirement to perform a dynamic balance of the ground-adjustable pitch propeller at the next condition inspection or sooner, and any time the prop pitch is changed.

Does this mean that I need to do this before I have the DAR come out for the initial E-LSA AW inspection? Or will I be good?.. and can fly to a shop that has dynamic balancing equipment after the AW cert? (i don't think the local shop on my airfield does balancing)
 
Throttle Spring Retainer VA-00276

Greetings,

Please make the retainer part number VA-00276 available to order online.
It currently cannot be found or ordered online.

Thanx,

Mike Clark
 
Please make the retainer part number VA-00276 available to order online.
It currently cannot be found or ordered online.

It's searchable now - you can search for "VA-00276" on the web store home page. It will come up in the search results and is available for order.
 
Does this mean that I need to do this before I have the DAR come out for the initial E-LSA AW inspection? Or will I be good?.. and can fly to a shop that has dynamic balancing equipment after the AW cert? (i don't think the local shop on my airfield does balancing)

You should complete the dynamic prop balance at your first opportunity. Your DAR should not require the Service Letter be completed to issue the airworthiness certificate. We'll take a second look at the language of our service letter, as well. Prop balancing is not often practical to have completed prior to the first flight, due to circumstances such as yours, but it should be done as soon as you are able since setting the initial pitch is technically considered a change. A dynamic balance can make a real difference and can result in a significantly smoother running/feeling engine and will help prevent vibration-induced damage over time, as well as potential vibration-related electronics issues that can occur at any time.
 
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Given that the prop blades must be removed at each conditional inspection to check the torque of the hub, does each condition inspection constitute a "change" and repeat dynamic balance? Does re-installing the blades to the same pitch as "last time" suffice to avoid the requirement to balance again?

I have spoken with two shops that do dynamic balancing, but they were leery of working on the 912, due to the reduction gearing. Do you have any technical references we can use to help such shops to accomplish a dynamic balance?

Thanks in advance,
-dbh
 
Given that the prop blades must be removed at each conditional inspection to check the torque of the hub, does each condition inspection constitute a "change" and repeat dynamic balance? Does re-installing the blades to the same pitch as "last time" suffice to avoid the requirement to balance again?

I'll be interested in the answer to this question. Very costly to dynamic balance prop every year...
 
Yes, I absolutely agree that balancing is worth the effort.. for comfort and for engine life.. and I did plan on flying out somewhere to do it after Phase I. Just trying to get through the DAR process without getting jammed up on anything.
 
Given that the prop blades must be removed at each conditional inspection to check the torque of the hub, does each condition inspection constitute a "change" and repeat dynamic balance? Does re-installing the blades to the same pitch as "last time" suffice to avoid the requirement to balance again?
-dbh

Fortunately for the newer propellers, the Sensenich ICA doesn't require removing the blades during the annual inspection.
 

Attachments

  • Sensenich propeller ICA Apr 2019.pdf
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I'm also interested in finding a shop that will perform this service for my -12 once I am done building. If anyone has any recommendations for places in the north eastern US I would appreciate hearing about them.

Googling did yield this article: https://www.kitplanes.com/balancing-act/ which shows how to perform this on a -12.
 
Yes, I absolutely agree that balancing is worth the effort.. for comfort and for engine life.. and I did plan on flying out somewhere to do it after Phase I. Just trying to get through the DAR process without getting jammed up on anything.

Definitely understood. Check your PMs - thanks.
 
Everyone - Anticipate an update from us in the next couple/few days on the prop balancing requirement topic. We will post updates here.

Thx

greg
 
Not sure why you need to remove the blade. If the nuts don’t budge I call it good. A couple of annuals the nuts moved and I had to pull the blades to access the bolt heads, but usually the thunder gods smile upon me.
 
Dynamically Balancing Prop

I’ve been thinking about this…. What if I have an accident with my airplane and my insurance company disallows a claim because of non-compliance with Service Letter or Service Bulletin?

I can see a lawyer’s argument going like this… “It says right here that Van’s Aircraft recommends removing the propellor every twelve months for inspection and they also recommend dynamically balancing the propellor every time it is disassembled. The logbooks show that the airplane owner/builder decided against Van’s Aircraft recommendation and did not dynamic balance his propellor every year”.

Can you imagine what a peer group of twelve individuals what conclude? In a legal proceeding, I doubt if there would be any distinction between Service Letter and Service Bulletin. In either case, the aircraft designer is recommending a maintenance inspection for continued airworthiness. The lawyer would probably make the case that the owner is acting as an A&P mechanic and has no formal training to do so. Airplanes crash and juries are sympathetic. Throw in the word “Experimental” and all bets are off.

Words have meaning – PILOT’S LIVES MATTER.
 
Jim's words are correct here, I'm not sure where this is going but to have wording about balancing a prop as a S/B is a touchy at the very least.
I've done my prop balancing several times, and so far my balance master has worked the best so I actually always have a balanced prop no matter what I do or touch on it.
 
What I don't understand is a good many RV12's have been flying for 10 years plus, why is this now required? As I see it "Letters" are a recommendation and not mandatory. Also there seems to be a SB or SD that comes out after a few months like the NLG replacement which I believe was due to one incident. What has happened to cause the need for Prop balancing? This stuff seems to be never ending...
 
RV-12/RV=12 is Service Publication UPdates dated October 6, 2020

Jim,

I just don't see an insurance company denying a claim because a service bulletin was not done. If the aircraft is E-LSA, service bulletins are not required. The other side of the argument is if the manufacturer thought it was required, they would have issued a safety alert which is required.
 
Jim,

I just don't see an insurance company denying a claim because a service bulletin was not done. If the aircraft is E-LSA, service bulletins are not required. The other side of the argument is if the manufacturer thought it was required, they would have issued a safety alert which is required.

I have completed all SB's to-date but I have no intention of disassembling the prop and dynamic balancing every twelve months...
 
I have completed all SB's to-date but I have no intention of disassembling the prop and dynamic balancing every twelve months...

I would think that, at least on the E-LSA model RV-12, that this would be a directive from Sensenich, not Van's? They build and manufacture the parts that would need balancing, that Van's buys and redistributes for sale.
 
Here’s my vote on annual prop balance:👎

How many times did Vans balance the prop on their original factory demo airframe?
 
SL-00024 REV 1 Published

We published SL-00024 REV1 this morning, which expands the language and clarifies time of compliance requirements.

What changed:

  • For aircraft that are within the first 15 hours of flight, or which are currently under construction: Complete the propeller balance before reaching 15 total flight hours.
  • For flying aircraft that have already exceeded 15 hours of flight and have not had a propeller balance: Complete the propeller balance within the next 10 hours of flight.
Also, note that this SL references new revisions the Maintenance Manual (MM) and Production Acceptance Procedures (PAP) documents for the RV-12 and RV-12iS. Those are in process and we plan to publish them the next few business days. We are publishing the revision to the Service Letter to help get timeframe clarity to everyone now.​

Thanks for your patience on this one.

greg
 
Here’s my vote on annual prop balance:👎

How many times did Vans balance the prop on their original factory demo airframe?

It's has been and continues to be balanced in a manner that is consistent with this service letter - and then some. We make changes to those airplanes all the time, and prop balancing has always been something we do as a matter of course.

The original "legacy" RV-12 demonstrator was recently sold to our employee flyting club, and they also balance the prop per the terms of this SL.

Balanced prop = smoother, less-prone-to-fatigue, safer airplane.
 
Why

Can somebody explain why this has suddenly become an issue? Has there been some incidents because of this?
 
Can somebody explain why this has suddenly become an issue? Has there been some incidents because of this?

Yes. There have been multiple examples of damage/issues caused by imbalance of the propeller. These include but are not limited to broken pitot tubes, ADAHRS error or failures, and fatigued of parts.
 
Yes. There have been multiple examples of damage/issues caused by imbalance of the propeller. These include but are not limited to broken pitot tubes, ADAHRS error or failures, and fatigued of parts.
Why would a propeller imbalance cause ADAHRS failures? The answer is important to me because I have been having ADAHRS failures, and haven’t found the cause even after replacing the ADAHRS three times.
 
Why would a propeller imbalance cause ADAHRS failures? The answer is important to me because I have been having ADAHRS failures, and haven’t found the cause even after replacing the ADAHRS three times.

Failure, meaning vibration-induced failure to properly display accurate information due to vibration transmitted through the airframe to the electronics unit is what we have observed at times. Of course there are a variety of things that can cause vibration-related issues on an ADAHRS unit.
 
There is an important change that took me by surprise when I was printing out PAP v2.3 (issued on 10/30/2020) not mentioned in the ChangeLog on the website:

Change trim adjustment knob position for Garmin autopilot installations

Previously, the PAP instructed you to increase the potentiometer position to a point where the trim motor starts working, then add 1/8th of a turn.

The new instructions have you change the pot to the maximum setting.

I'm not sure why the change, or exactly what this setting does, but it seems important since too low of a setting seems to prevent the trim buttons on the stick from working.
 
There is an important change that took me by surprise when I was printing out PAP v2.3 (issued on 10/30/2020) not mentioned in the ChangeLog on the website:

Change trim adjustment knob position for Garmin autopilot installations

Previously, the PAP instructed you to increase the potentiometer position to a point where the trim motor starts working, then add 1/8th of a turn.

The new instructions have you change the pot to the maximum setting.

I'm not sure why the change, or exactly what this setting does, but it seems important since too low of a setting seems to prevent the trim buttons on the stick from working.

Yes, a change was made in the latest PAP: The trim adjustment knob setting on the AV-60000 was changed to "max" due to issues where the trim motor was not driven at the correct speed for some G3X installations.

So if the aircraft's trim works as desired, there is no need to change anything (which is why we are just changing the PAP and not publishing some other service doc). If the trim motor doesn't work as desired (doesn't run correctly), one can make the adjustment to the setting on the AV-60000. Of course, if the airplane is already flying the trim motor functionality should already have been set and confirmed in the process of the acceptance procedures and any anomalies addressed prior to flight (as with all anomalies). This was noted on a small number of builds and hence addressed in the PAP.
 
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I didn’t see this service letter for prop balancing until a few days ago and didn’t find a lot of choices in SE WI for this service. I talked with the CubAir A&P at HXF in Hartford, Wi about this and he now has a new DynoVibe on order. I will be first in line to get my prop balanced by him.

He will also supply this service as part of his contribution to our Hartford High School RV 12 build program. Some times it just pays to ask.
 
dynamic balancing

I'm a little late to the party, so this is a bit of a shotgun blast on various aspects of prop balancing and the Sensenich product line.

A propeller dynamic balance addresses the entire rotating assembly on the aircraft, including engine, spinner, spacer, mounts, etc, not just the propeller.
Even if every individual part is perfectly in spec for balance and geometry, there are manufacturing tolerances to everything on earth and tolerance stackup can result in the propeller assembly being slightly off center or an out of balance tolerance.

Once a dynamic balance is complete, you don't have to redo it until there is a major change to ANY of the following: propeller, spinner, engine, gearbox, or engine mounts.
You can take the propeller or spinner off or even take out the blades, just make sure everything is placed back in exactly the same original position.
This includes all the spinner parts are put back in the same index positions.
**A new dynamic balance would be required if any parts are changed out or if the propeller blades are replaced, repaired, repainted, or positions swapped in the hub. Small parts such as spinner screws or prop bolts can be replaced without a new dynamic balance, but replacing spinner plates, spinner dome, blades, hub halves, etc will invalidate the dynamic balance and require a new balance job.


To date, Sensenich has not required a dynamic balance for continued airworthiness or for installation of any of our propellers, be they wood, metal or composite.
Rotax requires a dynamic balance for any new propeller installation on the 912 series of engines. This is specified in the Rotax 912ULS Installation Manual IM_912 edition 2 revision 1 Chapter 61-00-00 page 4.
Van's recently released a Service Letter on RV12 aircraft that mandates dynamic balance on the propeller as part of the Production Acceptance Procedure. SL-00024 10-30-20. This is to be within the first 15 operating hours.
While not required by Sensenich, a dynamic balance is certainly recommended for new installations since it can reduce vibration from the entire rotating assembly and provide a more pleasant aviating experience.
While propellers are sometimes the culprit, vibration can also come from the following: spinner out of balance, spinner setup (wobbles during rotation), mounting flange runout, spacer tolerances (not used on RV12), carburetors not sync'd, gearbox overload clutch too tight, etc.


Our early two blade aircraft hubs, model 2A0R5 revision D or earlier, do have a disassembly inspection specified for annual. This was a carry-over from our earliest composite propeller procedures over 20 years ago for all propeller/engine combinations.
With over 25 million operating hours across our composite propeller models, we have been slowly updating maintenance instructions on our most recent models with extended disassembly intervals.
Our latest 2A0R5 hubs (revision E and later with three holes in the hub cover) and our Service Bulletin hub cover replacements (revision D1 with only a single big center hole) do not require disassembly until reaching the 2000 hour Time Before Inspection interval.

A dynamically balanced two blade prop can be pretty smooth, but a three blade propeller is just inherently smoother from the start.
Blatant advertising: Sensenich released a new 3 blade 70" adjustable pitch carbon propeller in 2019 with better performance than our 2 blade propeller, and it can be removed from the engine in one piece without taking it apart and having to reset blade angles on reinstallation. It does require an all new spinner, though.


Steve B at Sensenich
 
I sort of stated that I thought it was Sensenich's call on balancing requirements about a month ago, they make them, they warranty them.

Except it is not their call. At least not exclusively.
Sensenich is an oem part supplier for the RV-12.
That does give them authority to issue service related inspection requirements, bulletins, etc., but vans aircraft manufacturers the airframe and has authority to regulate anything related to that complete entity.
 
I just bought a Dynavibe GX3 to balance my 912 and provide the service to others.

I had balanced it 100 hours ago with an older Chadwick that had not had calibration in some time. The builder of my -12 helped and we got it to .06 ips (according to the Chadwick). The previous balance was a few years prior and I did not read the ips before starting. In any case the .06 was a noticeable difference, not only to me but to other non-aviation passengers.

Today I spent some time learning the Dynavibe and working with it and my plane. I did 3 consecutive balances and each one ended the same with similar weight solutions. Before I started the balance was .10 ips. Now it is finished it is .02 ips. It is considered a good balance if it's below .07 ips. I went further to a finer balance to see how precise I could get. The GX3 is a good tool.
 
I just bought a Dynavibe GX3 to balance my 912 and provide the service to others.

I had balanced it 100 hours ago with an older Chadwick that had not had calibration in some time. The builder of my -12 helped and we got it to .06 ips (according to the Chadwick). The previous balance was a few years prior and I did not read the ips before starting. In any case the .06 was a noticeable difference, not only to me but to other non-aviation passengers.

Today I spent some time learning the Dynavibe and working with it and my plane. I did 3 consecutive balances and each one ended the same with similar weight solutions. Before I started the balance was .10 ips. Now it is finished it is .02 ips. It is considered a good balance if it's below .07 ips. I went further to a finer balance to see how precise I could get. The GX3 is a good tool.

Previous owner balanced mine, when he did the Sensenich hub update, but I'm curious to what level. Once I finish up my PPL, I'd like to see how well mine checked out, to verify, with you sometime out at REI.

Randy
 
I just bought a Dynavibe GX3 to balance my 912 and provide the service to others.

I had balanced it 100 hours ago with an older Chadwick that had not had calibration in some time. The builder of my -12 helped and we got it to .06 ips (according to the Chadwick). The previous balance was a few years prior and I did not read the ips before starting. In any case the .06 was a noticeable difference, not only to me but to other non-aviation passengers.

Today I spent some time learning the Dynavibe and working with it and my plane. I did 3 consecutive balances and each one ended the same with similar weight solutions. Before I started the balance was .10 ips. Now it is finished it is .02 ips. It is considered a good balance if it's below .07 ips. I went further to a finer balance to see how precise I could get. The GX3 is a good tool.

I just purchased one as well and am waiting for it to be shipped. I plan to provide the service to others. So if anyone needs to balance I am in Eastern Washington. I will be doing them for free for a short time to learn the art and gain experience.
 
seagull,
Can you provide some pictures of your setup and some instructions on the process?

The instructions are not difficult but more than I want to write here. You can find manuals online for the balancer.
To state it simply, you mount the optical sensor and accelerometer to the engine in the correct locations and alignment > run the engine at cruise RPM > take reading > shutdown > add weights as recommended by the balancer > repeat. After each test the ips will be reduced. When you are at the ips level that is acceptable to you remove test weights and mount permanent weight.

50641191853_d56d8dddf2_c.jpg
 
Can you tell us what the “test weights” are and how they’re applied?

The test weights are normal flat washers. Stack a few up to get the total grams required. In the case of the RV-12 the "test" weights are added under the head of the screws that attach the spinner to the backplate (10). typically the balancer will split the total weight between 2 adjoining screws. The final weight is calculated for a smaller diameter and added to the back plate with a bolt and nut. You drill the hole at the recommended position.
 
Thanks very much. It’s something I’ve been wondering about- simple when you know the answer.
 
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