Notice just added to Factory site: (FF-1207)

[dick seiders]

WOW! Thanks, John. I never saw the post by Larry because I looked away for about a minute. I am amazed that so many are having the problem! It's clear to me now what a major issue it is. I will take my 12 down and check the bolts this weekend and provide feedback. I only have 43 hrs, but I will look. I will still call on Rotax at Lockwood for input. Does anyone know if the correct size Nordlocks are available and will they fit the recessed hole? Perhaps the Nordlocks with Loctite Blue in combination is the answer?
I won't fail to check this site again for more than a day or two as it's obvious that it is RV12 flyers talking to one another that will save our a--es and likely before any other comunication from mfrs. The only suggestion I want to make to all is when something this hot happens maybe we should put URGENT in caps in the thread title. I rolled right by the thread w/o checking it as I felt -well that's just addressing a 100 hr check issue.
Thanks again John for alerting me.
Dick Seiders

[Mich48041]

The Nord-Lock NL10 washer dimensions for 10mm bolts are:
10.7mm hole, 16.6mm OD, 2.0mm thick
http://www.nord-lock.com/default.asp?url=337.16.37
I do not know the hole size of the engine mount.
So far I have found two sources:
http://www.mcmaster.com/#nord-lock-washers/=9vo5pp
http://www.clipsandfasteners.com/Nord_Lock_s/210.htm
Joe

[MartySantic]

I tried to take a measurement at the hangar, but, could not get dial micrometer reading. Way too much stuff in the way. Will have to take a set of calipers out there and measure the ID of the bushing. Anyone have it in their garage?

[mrt890]

Mcmaster-Carr indicates that the bolt head diameter is 16.0mm so a nord-lock washer set may fit.

[JohnF]

I hope I ordered the correct Nord Lock washers from McMasters. I asked for their part # 91074A131, 0.65" OD, and 0.4"ID. $5.25 for a set of 10 pair..
their catalog shows them for a M10 bolt.

[MartySantic]

Just remember, Nordlock washers and loctite have not been suggested, or approved by Rotax or Van's. They may or may not be a good solution. If you use them, you have become the design engineer, assuming all the responsibilities of the design engineer!!

I am going to modify the shroud, check all four capscrews (at 360 in-lbs), and WAIT for a preventative solution from Van's. And then, most likely reduce the inspection interval until the solution comes our way.

[dick seiders]

Marty, you are probably correst, but the Nordlocks, (if the bolts are long enough) and blue loctite can't hurt. The question is how long till we hear from Van's? I don't intend to ground my 12 for an indefiinite period. An interim fix is better than none and the blue loctite sounds like it has been working for those who have tried it. I will plan to re-check the fasteners at each oil change, or 35 hrs.
Dick Seiders

[Tony_T]

Originally Posted by MartySantic

Just remember, Nordlock washers and loctite have not been suggested, or approved by Rotax or Van's. They may or may not be a good solution. If you use them, you have become the design engineer, assuming all the responsibilities of the design engineer!!

Well, maybe, Marty, and part of the reason for the 2" high sign we see when we climb aboard.

With the present design, every time I head out across the Straight of Juan De Fuca I would be visualizing those bolts jiggling loose like in the video you posted. Not going to go that way.

According to their website Nord-loc washers have been available since 1982, but are apparently not well known in the experimental aircraft world. My DAR ogled the bolts on the brake caliper and asked why they were not safety wired. And again on the prop bolts. I had to explain that they use the Nord-Loc washers, that the bolt heads were not drilled, and that I was not instructed to safety them. I am not sure he had heard of the Nord-Locs.

I have ordered the Nord-Loc washers and if they fit in the holes, will try these, without Loctite. This will allow checking the torque on a frequent basis like you do on the Nord-Loced prop bolts, and with a torque wrench. Nord-loc claims "NORD-LOCK washers positively lock the fastener in a joint which is subjected to extreme vibration or dynamic loads." That would be us. We'll see.

If they loosen then I will probably take off the Nord-Locs and use the split washer and Loctitle 243. Loctite 243 is on the list of chemical stuff that appears in the Rotax manuals although I don't find anywhere where they apply it to the engine mount bolts. But Loctite seems to be the way majority of the industry has gone. I doubt that combining the Nord-Locs and Loctite would be appropriate, but without expert design, who knows?

In rereading the Shroud Modification notice (its not a SB), it looks like Van's feel they have done enough and it is our responsibilty to comply with all Rotax maintenance requirements. I doubt if they are going to propose anything further.

It will be educational to see how the various solutions work out, guys, please keep posting your experiences.

Tony
P.S. Loctite 242 and 243 are both "blue" medium Loctite. I find 242 in the hardware store. I had to order 243 on the internet. 243 is marked "industrial" and has almost twice the break loose torque of 242. They are both in a small inexpensive tube, in a bubble wrap.

[MartySantic]

Sure wish we could get some indication from Van's if more is forthcoming? But, as you have stated, Van's has not issued anything as of yet. DR has a good web-crawler and found the file before any "real" or "official" mother ship notification. A simple yes or no would go a long way to remove some of this tension.

[Peterk]

Originally Posted by Tony_T

Well, maybe, Marty, and part of the reason for the 2" high sign we see when we climb aboard.

With the present design, every time I head out across the Straight of Juan De Fuca I would be visualizing those bolts jiggling loose like in the video you posted. Not going to go that way.

According to their website Nord-loc washers have been available since 1982, but are apparently not well known in the experimental aircraft world. My DAR ogled the bolts on the brake caliper and asked why they were not safety wired. And again on the prop bolts. I had to explain that they use the Nord-Loc washers, that the bolt heads were not drilled, and that I was not instructed to safety them. I am not sure he had heard of the Nord-Locs.

I have ordered the Nord-Loc washers and if they fit in the holes, will try these, without Loctite. This will allow checking the torque on a frequent basis like you do on the Nord-Loced prop bolts, and with a torque wrench. Nord-loc claims "NORD-LOCK washers positively lock the fastener in a joint which is subjected to extreme vibration or dynamic loads." That would be us. We'll see.

If they loosen then I will probably take off the Nord-Locs and use the split washer and Loctitle 243. Loctite 243 is on the list of chemical stuff that appears in the Rotax manuals although I don't find anywhere where they apply it to the engine mount bolts. But Loctite seems to be the way majority of the industry has gone. I doubt that combining the Nord-Locs and Loctite would be appropriate, but without expert design, who knows?

In rereading the Shroud Modification notice (its not a SB or even a letter), it looks like Van's feel they have done enough and it is our responsibilty to comply with all Rotax maintenance requirements. I doubt if they are going to propose anything further.

It will be educational to see how the various solutions work out, guys, please keep posting your experiences.

Tony
P.S. Loctite 242 and 243 are both "blue" medium Loctite. I find 242 in the hardware store. I had to order 243 on the internet. 243 is marked "industrial" and has almost twice the break loose torque of 242. They are both in a small inexpensive tube, in a bubble wrap.

I agree...Van's is done with the issue...they are not in the business of guarantees. Mine is down for the conditional so I will be very interested in the nordlock results. In fact, I'll probably just go ahead and order them while I've got everything apart. They're not cheap but we don't need that many. And like you said, they do a pretty darn good job of holding my prop on.