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-   -   RV-12: Engine Mounting Cap Screws Inspection (https://vansairforce.net/community/showthread.php?t=65020)

MartySantic 12-01-2010 09:08 PM

Quote:

Originally Posted by DonFromTX (Post 489896)
Think of the poor slobs flying around in 12's that are NOT on this forum!

I posted the same a week ago. Van's has always sent an e-mail to the RV-12 owners when an issue has arisen.

I have not received such an e-mail for this VERY important AIRWORTHINESS issue. Van's Aircraft is ON my RV-12 nameplate. Should I not expect more??

Yes, a post is on their website. BUT, an e-mail to all owners would be most appropriate. I am aslo worried about the guy that is flying and really does not monitor VAF or the net.

This has been and will continue to be my only beef with Van's with respect to this issue. Van's should have made the effort to contact all. Sad!!

Will I build another..... Will I recommend the RV-12 to others...........Let's see how this issue comes to conclusion.

DonFromTX 12-01-2010 09:34 PM

I can certainly understand taking a careful look at the whole problem rather than some quick and silly stuff, but some sort of warning would be of no cost to them while they engineered a top notch solution. After all, keeping a bolt from coming loose on an aircraft is not something that has never been solved before.

rgmwa 12-01-2010 11:10 PM

Quote:

Originally Posted by DonFromTX (Post 489920)
I can certainly understand taking a careful look at the whole problem rather than some quick and silly stuff, but some sort of warning would be of no cost to them while they engineered a top notch solution. After all, keeping a bolt from coming loose on an aircraft is not something that has never been solved before.

I agree. However if you read the first couple of lines of the Service Notice, it is quite clear that Vans regard checking of these bolts "at regular intervals" as a Rotax maintenance requirement. As they go to some trouble to quote the relevant Rotax Maintenance Manual references, it's probably hard to dispute this.

They have also flagged the seriousness of these bolts coming loose by recommending a check "before further flight". This, together with the modification allowing access to all the bolts for inspection purposes, is probably all they need to do to satisfy their duty of care obligations.

However, I think an initial email to all Rotax purchasers alerting them to the problem, and advising them to check the Service Notice would have been a responsible move, and avoided some of the negative comments that have been expressed here.

I also doubt that they will come up with any recommendations for securing the bolts, as it is clear from the notice that these are regarded by Vans as Rotax bolts, not Van's bolts. If that is the case, then perhaps Rotax will issue something, but Vans are probably not in a position, legally, to go any further at this point. At least, not without input from Rotax.

DonFromTX 12-02-2010 07:36 AM

I understand, that makes sense. Thanks

Geico266 12-02-2010 07:58 AM

Quote:

Originally Posted by rgmwa (Post 489943)
I agree. However if you read the first couple of lines of the Service Notice, it is quite clear that Vans regard checking of these bolts "at regular intervals" as a Rotax maintenance requirement. As they go to some trouble to quote the relevant Rotax Maintenance Manual references, it's probably hard to dispute this.

Rotax makes airplane engines, not airplanes. Their engines are installed into airframes. The Rotax Installation manual, Page 35 states the bolts used to secure the engine to the airframe are the responsibility of the airframe manufacturer, that would be Vans Aircraft. Other airframe manufacturers have issued SB's to cover these exact same bolts dating back to 1999. The real question is; Why can't Vans Aircraft step up to the plate and warn their customers of what is clearly an airworthiness issue. Clearly, IMHO this is their responsibility.

clucier 12-02-2010 09:45 AM

(In regards to Verns post on Lockwood)

Vern, if they did not check one of the bolts which is a required item in the 25 hour inspection how did the sign off that they completed the inspection, frankly that is disturbing, they just decide not to check a bolt when it is difficult? If this is true I would never seriously consider using them again, especially since bolts have been found (or rather not) to be missing.

MartySantic 12-02-2010 10:00 AM

Quote:

Originally Posted by clucier (Post 490023)
(In regards to Verns post on Lockwood)

Vern, if they did not check one of the bolts which is a required item in the 25 hour inspection how did the sign off that they completed the inspection, frankly that is disturbing, they just decide not to check a bolt when it is difficult? If this is true I would never seriously consider using them again, especially since bolts have been found (or rather not) to be missing.

You should be asking not Vern, not Lockwood but the company with the highest time RV-12s. Please do not crucify anyone for sharing! Sharing such information may save your arse.

vernhendershott 12-02-2010 11:30 AM

Hi Chris,

The bolt that they could not have checked was fine, for what that is worth, we can all have bad days, perhaps this was one of theirs. The only reason I mentioned it is if they did check the other three, then one fell out in about 10 hours, so if we are to set a reasonable interval to see that the bolts are still tight what should it be? With the data presented on this list I would expect the FAA to issue an AD Note requiring the checking of the bolts every 5 hours if they did AD Notes on experimental aircraft, we are lucky that they do not but if we follow Van's current instructions (install the bolts and split ring lock washer dry to the called out torque) then we should be checking the torque about every five hours. Forgive me if this does not sound like the kind of fun I wanted to have.

I think with blue loctite we should be good with a drop of Torque Seal and a visual inspection at 25 hours for now and if the situation remains stable then perhaps fifty hours which would match up with the oil change interval and it would not be much of an issue.

The above is only one man's thoughts, you should come to your own conclusions and do what you need to, to keep your aircraft safe to fly.

Best regards,
Vern

jte65 12-02-2010 12:16 PM

Have any loosened following previous confirmation they were tight?
 
I asked this question as part of a post within the related thread a few days ago but have not seen any replies so I will ask it again.

Has anyone found a loose bolt following a prior confirmation that they were still fully torqued? In other words, has anyone else definitively checked all of them at say 25 hours and then had them come loose later? Sounds like Vern does not know for sure whether his were checked given that he did not do the check himself. This seems like an important question, as it may suggest that if they do not loosen during the initial 25 hours, perhaps they will not subsequently. Also helps those of us who found ours tight at 25 hours to gauge how frequently we need to recheck them.

Jeff

MartySantic 12-02-2010 12:24 PM

Read back thru this thread. John's (okiejohn) info on page 3 of this thread may be the answer you are looking for. There are a couple of others.

JBPILOT 12-02-2010 01:56 PM

THE FACTS ARE - -
 
The bolts come loose - PERIOD ! Does it make a difference when - really ! They come loose. Loose bolts will create lots of problems in the threads.

Put on plenty of Loctite 'blue', and paint mark them, then LOOK at them as often as you feel comfortable. If you have good threads, put on plenty of Loctite, and *THEN* you have a problem - that is when we need to hear from you ! I think we have the solution. I have about 100 hours on mine since I put Loctite on them. HAVE NOT MOVED ! That is good enough for me. DO NOT BREAK THEM LOOSE to check them. If they have not moved, they are tight enough. If you feel the need to take one out, clean the threads and do it all over again, but just LOOK at them, don't try to tighten them or you will break loose the Loctite and then it will not be as affective.

John Bender

DonFromTX 12-02-2010 01:58 PM

I think you are correct, we are looking for a complicated solution to a simple problem.

rgmwa 12-02-2010 02:53 PM

Quote:

Originally Posted by Geico266 (Post 490000)
Rotax makes airplane engines, not airplanes. Their engines are installed into airframes. The Rotax Installation manual, Page 35 states the bolts used to secure the engine to the airframe are the responsibility of the airframe manufacturer, that would be Vans Aircraft. Other airframe manufacturers have issued SB's to cover these exact same bolts dating back to 1999. The real question is; Why can't Vans Aircraft step up to the plate and warn their customers of what is clearly an airworthiness issue. Clearly, IMHO this is their responsibility.

Larry, I agree entirely that VAN's should have been much more pro-active in dealing with this critical safety issue, and I can only assume it's a case of "responsibility shared, responsibility halved". I'm just trying to understand how they may be thinking based on their actions so far.

clucier 12-02-2010 05:01 PM

Quote:

Originally Posted by vernhendershott (Post 490057)
Hi Chris,

The bolt that they could not have checked was fine, for what that is worth, we can all have bad days, perhaps this was one of theirs. The only reason I mentioned it is if they did check the other three, then one fell out in about 10 hours, so if we are to set a reasonable interval to see that the bolts are still tight what should it be? With the data presented on this list I would expect the FAA to issue an AD Note requiring the checking of the bolts every 5 hours if they did AD Notes on experimental aircraft, we are lucky that they do not but if we follow Van's current instructions (install the bolts and split ring lock washer dry to the called out torque) then we should be checking the torque about every five hours. Forgive me if this does not sound like the kind of fun I wanted to have.

I think with blue loctite we should be good with a drop of Torque Seal and a visual inspection at 25 hours for now and if the situation remains stable then perhaps fifty hours which would match up with the oil change interval and it would not be much of an issue.

The above is only one man's thoughts, you should come to your own conclusions and do what you need to, to keep your aircraft safe to fly.

Best regards,
Vern

Thanks Vern,

I was not looking to crucify anyone but it concerns me if someone I am paying to do a thorough required inspection of a machine that could kill me if improperly maintained misses a step, i start wondering what other steps did they miss or just not complete. No one is perfect but thats why we use checklists, I would suspect they have checklists for the inspections, I know I would.

if they just chose not to do it because the shroud was difficult they should inform you of that and let you make a decision.

I truly hope it was a once in a long while event but ask yourself what if the tech "forgot" to torque your prop and it came off in flight.

I digress, and from everything I hear and see (until this) Lockwood is a first rate organization so not trying to beat them up to badly here but....

I truly hope everyone continues to share information like this good bad or in-different, it,s what makes a difference in our hobby.

rschy 12-02-2010 05:02 PM

Quote:

Originally Posted by MartySantic (Post 489902)
I reviewed the ROTAX Line Maintenance page. What are you trying to tell us?? It is merely a list of consumables??? The manual SPECIFICALLY tells us when and when not to use loctite.

In the case of the engine mount bolting, all of the USA repair centers seem to be using blue loctite for this bolting even tho the line maintenance manual does NOT suggest it.

DUH...... This tells me that Rotax is routinely using Loctite to secure BOLTS and has proof that the product works. As well as properties of the the different types of thread locking products.

BTW 120367 has 19.5 hours and the 3 bolts I check are good but I used blue Locktite on all the fasteners without self locking female ends.

Marty, I'm sorry I made such a stupid post. I thought it might be of interest to some of folks with an imagination!!!!!!!

Boomerang 12-02-2010 05:47 PM

Loose bolts on N7185A, SN#120164, with 52 hours
 
Checked the bottom two bolts right after Larry called me (Thanks Larry) and found the bottom right tight. The bottom left needed about 1/8 turn. Was not able to check the top two bolts at that time because of the inaccesability. The top right looked OK but I really did not look very close at the top left. Just assumed that it was OK. Did a closer visual check today of the top left bolt. The bolt head is just about even with the outside edge of the engine mount. How loose it is (how many turns counter clockwise) I won't know until I can get in there but as a result I am grounded until I can get my 12 to a heated work area. This will take a while. A real bummer.

dick seiders 12-02-2010 08:33 PM

Heard from Rotax Tech again today. He was not willing to commit on the blue Loctite, but I have read enough to feel firm on the 360 torque setting, blue Loctite, and torque seal with checks at each oil change. Until something better comes along, if it does that's where I am going.
Dick Seiders

Peterk 12-02-2010 09:16 PM

What is Going On?
 
Quote:

Originally Posted by dick seiders (Post 490233)
Heard from Rotax Tech again today. He was not willing to commit on the blue Loctite, but I have read enough to feel firm on the 360 torque setting, blue Loctite, and torque seal with checks at each oil change. Until something better comes along, if it does that's where I am going.
Dick Seiders

Certainly is curious. Bolts coming out right and left. Van's doesn't care, the Feds don't care (or don't read VAF...yah right). Those that Loctite swear by it, but neither the engine manufacturer nor the aircraft manufacturer...whom both recommend Loctite in much of the remaining assembly will not do so in this instance. What a bizarre situation! Of course no one did anything about the Zenith wings coming off until how many crashed? Am I missing a liablity issue here? Guess we'll find out when the first 12 smokes a hole in the dirt.

Geico266 12-03-2010 06:50 AM

Quote:

Originally Posted by Peterk (Post 490244)
Certainly is curious. Bolts coming out right and left. Van's doesn't care, the Feds don't care (or don't read VAF...yah right). Those that Loctite swear by it, but neither the engine manufacturer nor the aircraft manufacturer...whom both recommend Loctite in much of the remaining assembly will not do so in this instance. What a bizarre situation! Of course no one did anything about the Zenith wings coming off until how many crashed? Am I missing a liablity issue here? Guess we'll find out when the first 12 smokes a hole in the dirt.

Well said Pete.

The silence from Vans is deafening.

Mich48041 12-03-2010 09:43 AM

Two main issues
 
There are two main issues:

ISSUE 1. Notify RV-12 owners that the engine mount bolts are loosening and falling out.
This is a moral issue. Most of us would like to see RV-12 owners immediately notified to check the bolts. Until then, bolts are slowly vibrating out. RV-12 owners who have had engine bolts loosen can warn others by contacting aviation magazines and the EAA and the FAA. If the magazine editors received letters from several builders, they might write an article or publish the "letters to editors". The word will be spread.

ISSUE 2. Preventing the bolts from loosening.
Split ring lock washers do not work as evidenced by laboratory experiments and RV-12 field experience. It would be nice if we received official guidance on this issue. But manufacturer's do not know any more about solving this problem than the builders. Regardless of engineering theory, it is what works in the field that counts. Rotax mechanics have been using blue Loctite with success, even though they might be reluctant to officially recommend it due to liability concerns. And using blue Loctite seems to be the consensus among RV-12 builders. Nothing is perfect and Loctite has disadvantages. It has temperature limits, should not be disturbed by periodic torque checks, and makes removing bolts difficult. But it works and will keep the bolts from loosening. Another possible solution is using Nord-Lock washers. They work well holding the brake and propeller bolts. Nord-Lock washers are not affected by normal engine block temperatures; they can be periodically checked for torque; and the bolts can be easily removed with a wrench. But regardless of theory, they need to be proven in the field.

We can complain and try to influence others but we can not control what they do. What we can do is spread the word to other builders, perhaps with the help of national and international media. And we can ensure that our own engine mounting bolts do not come loose.
Joe

Peterk 12-03-2010 10:10 AM

Quote:

Originally Posted by Mich48041 (Post 490346)
There are two main issues:

ISSUE 1. Notify RV-12 owners that the engine mount bolts are loosening and falling out.
This is a moral issue. Most of us would like to see RV-12 owners immediately notified to check the bolts. Until then, bolts are slowly vibrating out. RV-12 owners who have had engine bolts loosen can warn others by contacting aviation magazines and the EAA and the FAA. If the magazine editors received letters from several builders, they might write an article or publish the "letters to editors". The word will be spread.

ISSUE 2. Preventing the bolts from loosening.
Split ring lock washers do not work as evidenced by laboratory experiments and RV-12 field experience. It would be nice if we received official guidance on this issue. But manufacturer's do not know any more about solving this problem than the builders. Regardless of engineering theory, it is what works in the field that counts. Rotax mechanics have been using blue Loctite with success, even though they might be reluctant to officially recommend it due to liability concerns. And using blue Loctite seems to be the consensus among RV-12 builders. Nothing is perfect and Loctite has disadvantages. It has temperature limits, should not be disturbed by periodic torque checks, and makes removing bolts difficult. But it works and will keep the bolts from loosening. Another possible solution is using Nord-Lock washers. They work well holding the brake and propeller bolts. Nord-Lock washers are not affected by normal engine block temperatures; they can be periodically checked for torque; and the bolts can be easily removed with a wrench. But regardless of theory, they need to be proven in the field.

We can complain and try to influence others but we can not control what they do. What we can do is spread the word to other builders, perhaps with the help of national and international media. And we can ensure that our own engine mounting bolts do not come loose.
Joe

Joe,

You have it nailed. Number 2 is easier than number 1. I, for one and others I know of are testing the Nordlock theory. Others, Loctite. I expected us to be the beta testers because as you say, "we are the field" and that is the way experimental aircraft are made safer. Your number 1 is very puzzling because it could save lives. We can only contact those we know of. Others have much larger resources to get the message out. And when you realize that many of them are readers and contributors to this forum its stunning. The EAA alone participates in this forum and yet ignores this issue. Are they all waiting for Van's to bless their comments? This is experimental, grass roots aviation, not corporate politics. Of course if you think about it, safety issues only become issues following fatalities. Shouldn't be much of a wait. Thanks for your personal concerns.

JohnF 12-03-2010 10:37 AM

Bolts
 
I have been thinking about this problem really hard of late. I have on hand the Nord Lock washers and both blue and red Loc Tite, and debating which to use.

Fortunately the real harm done so far is only to Van's reputation. I have been a customer since 1993 (I think it was) when I began building an RV6A, and now the RV-12, and in all that time I genuinely believed Van's organization was an honest and forthright organization. This current departure from their highly regarded (and deserved) reputation is really strange. Unless something is done promptly to repair this self-inflected harm it is going to take a long time to undo the damage.

Its only my opinion, and just like belly buttons, we all have one.

JBPILOT 12-03-2010 10:44 AM

Hey John - -
 
I would NOT recommend RED Loctite. It takes lots of heat to get them out, and that may create other issues. I'd again suggest BLUE, and check them often as you feel comfortable. After this morning, I am now at 209.9 hours. They seem to be fine. As I have also said, I have around 100 hours on them, and they have not moved. If we find the nord-lock washers to be good also, fine, use BOTH. You could take them out if you want/need to, but could fly with confidence they are not going to fall out.

John Bender

Jetguy 12-03-2010 12:00 PM

Notify Email From Vans!
 
I just received a Notify email from Vans containing the info about the mounting bolts. So now the info is going out to all owners.:D

E. D. Eliot 12-03-2010 03:16 PM

I have learned that
 
In life, when common sense and practicality 'appear' to have been left behind, that there is a lawyer is involved.

rgmwa 12-03-2010 04:17 PM

Quote:

Originally Posted by Jetguy (Post 490376)
I just received a Notify email from Vans containing the info about the mounting bolts. So now the info is going out to all owners.:D

It's good that they have finally notified owners by email, but you have to wonder why it has taken them nearly two weeks to get around to it. The service notice on Van's website is dated 19 Nov, just two days after Larry G first reported the problem here. I've had great service from Van's ever since I ordered my kit, but this apparent lack of urgency is a puzzle, given the potentially catastrophic consequences of losing these bolts.

Incidentally, they have just issued revision D of page 46-06 in the RV12 section on the website.

yankee-flyer 12-04-2010 08:53 AM

Bolts slightly loose at 20 hours
 
Just finished checking the bolts and modifying the engine shroud on N143WM at 20.1 hours.
All bolts were torqued to 310 in-lb PER THE RV-12 MANUAL at installation. At 20.1 hours all bolts required 10-15 deg of turn to go back to 310 in-lbs. I removed all the bolts, inspected them, coated them with lots of blue Loctite 243, reinstalled them and torqued them to 360 in-lb. All bolts were torque marked so I can see if they've moved at "regular" intervals, whatever "regular" comes to mean. I increased the size of the slot in the shroud so the upper left bolt could be removed. I did not remove the powder coating inside the mount since it hadn't been mentioned at the time and I'm not sure how it can be done with the engine in place.

After removing the lower right bolt it could not be reinstalled until enough pressure was put on ther arm of the mount to flex it down almost 1/16 inch. A friend whose entire career at Wright-Pat says that the problem is due to something in the structure flexing in the right way to set up a resonant frequency-- possible the lower right motor mount arm? That's the only bolt that did not go right back in.

The real problem, and one I'd think the whole LSA community would be VERY concerned about, is that the ONLY structural fasteners in the whole airplane that DO NOT have self-locking nuts, cotter pins, or safety wires are the 4 bolts holding the engine on! Is that ASTM standards??? If so, then I think the first time the FAA finds the engine of an RV-12 a half-mile from the crumpled wreckage, the result will make the CH-601 ruckus look insignificant!

My feeling is that the real solution may be a re-designed motor mount with a way to safety those 4 bolts.


Wayne 120241/N143WM

clucier 12-04-2010 09:07 AM

E-mail notification
 
Well maybe only to those with an engine, I have only the Empennage kit, no e-mail from them and I know they have it, but it makes sense as I don't have an engine yet.

Quote:

Originally Posted by rgmwa (Post 490463)
It's good that they have finally notified owners by email, but you have to wonder why it has taken them nearly two weeks to get around to it. The service notice on Van's website is dated 19 Nov, just two days after Larry G first reported the problem here. I've had great service from Van's ever since I ordered my kit, but this apparent lack of urgency is a puzzle, given the potentially catastrophic consequences of losing these bolts.

Incidentally, they have just issued revision D of page 46-06 in the RV12 section on the website.


MartySantic 12-04-2010 01:00 PM

All Four Capscrews Retorqued to 360 in-lbs
 
Finished checking all four engine mounting capscrews. At 85 hours, found three of the four slightly loose. Was able to get about 1/8 of a turn on the three. The fourth (one of the lower ones) need not budge at 310 in-lbs.

Van's tells you to use a ball end 8mm allen to get to the upper right capscrew. My drip tray was squarely in-line with the capscrew head and as such I had to remove the right side carb, the right side carb flange and drip tray. The o-ring popped out. It had swelled in diameter. It was not crushed. Could not get it back in the slot. Have another on order from LEAF. $6. Suggest having one on hand if you decide to remove the flange and drip tray. It also could have been my o-ring and how it reacted to alcohol free gasoline.

Felt I would get a better torque, and minimize any capscrew head damage if I was square to the capscrew head and had full allen wrench engagement?? A little more work but not hard and I felt better.

Did all of you guys that have checked the upper right have to REMOVE the drip tray??

The o-ring will be here Tuesday or Wednesday. No real problem as we got 7" of snow in the last 24 hours.

rgmwa 12-04-2010 04:20 PM

Quote:

Originally Posted by clucier (Post 490652)
Well maybe only to those with an engine, I have only the Empennage kit, no e-mail from them and I know they have it, but it makes sense as I don't have an engine yet.

Same here, Chris. I haven't received an email, but then haven't ordered my engine yet either. I hope that by the time I do, Vans and Rotax will have got their heads together and come up with an official fix.

Tony_T 12-04-2010 07:07 PM

Finished the "easy three", using Nord-Locs
 
About 3 weeks ago I found my bottom right was almost out and lost. The bottom left was about 1 turn from tight. I replaced the bottom two bolts dry and clean using the carbon steel Nord-Loc washers and no Lock-Tite. Because I wanted to get on the upper right bolt with a regular allen socket, like Marty I removed the right carb and drip pan. The O-ring was somewhat swollen in diameter. I used a bit of Easy-Turn fuel lube to stick it back into the slot. I will order a couple of spares for future. The upper right mounting bolt took about 30° rotation before the torque wrench clicked at 26 ft-lb. I replace the upper right lock washer using the carbon steel Nord-loc and no Lock-Tite. I torqued all three bolts to 30 ft-lb, dry, per the latest Notice. I ran out of time today and will need another day to do the shroud mod and the upper left bolt.
I am committed now to trying the Nord-Loc washers without Lock-Tite. I really want to be able to put the torque wrench on them when I inspect them. Because the Nord-Locs are unproven by field experience on the engine bolts, I plan to check them at 15 hours. Then 25 then perhaps longer. If the bolts loosen, I will probably remove the Nord-Locs and use Lock-Tite blue 243, like the majority of others. Right now I feel pretty confident the Nord-Locs will work and they are a more elegant solution than glue :rolleyes:.
I did an engine start today to check for leaks because I had done an oil change. The motor was noticeably smoother at idle with all the bolts back in. I had noticed some increased vibration when the motor was cold, and I thought it was due to colder weather. It was due to the loose bolts and so I wanted to mention the obvious; any increase in vibration would be reason to pull the cowls and check things over.

Tony

DonFromTX 12-04-2010 07:54 PM

Someone mentioned earlier that perhaps the bolts coming loose are NOT the problem, only the symptom of another deeper problem with the design of the engine mount itself. It seems to me that if it is flexing enough to loosen bolts, then perhaps it needs a brace somewhere to stiffen it up. If so, that would also shine some light on the slow response so far for a fix. I would submit that even after the bolts are secured, it may be a good thing to keep a close look at the motor mount itself, looking for signs of distress cracking etc...

rschy 12-04-2010 08:00 PM

Nord-locs are for application without heat cycles. Why wouldn't you loctite when a 100% of the people using it including myself haven't had any problems?
IMHO not using a ball driver like Van's suggest is a lack of common since. The problem is the powder coat anyway. Get rid of it and you can just use the split ring lock washers.

Mich48041 12-04-2010 08:06 PM

Nord-Lock washers
 
Quote:

Nord-locs are for application without heat cycles.
rschy,
Where did you read that? I am interested in reading the full report and reason behind that.
Thanks,
Joe

todehnal 12-05-2010 05:16 AM

Quote:

Originally Posted by Tony_T (Post 490818)
I am committed now to trying the Nord-Loc washers without Lock-Tite. I really want to be able to put the torque wrench on them when I inspect them. Because the Nord-Locs are unproven by field experience on the engine bolts, I plan to check them at 15 hours. Then 25 then perhaps longer. If the bolts loosen, I will probably remove the Nord-Locs and use Lock-Tite blue 243, like the majority of others. Right now I feel pretty confident the Nord-Locs will work and they are a more elegant solution than glue :rolleyes:.
Tony

Hey Tony,
I also am using Nord-Locs without the glue, only I am not flying yet. Please keep us informed as you accumulate hours. Not having loctite in there, you will be able to check the actual torque values for change! I sure like that idea.
Tom

Mark Henderson 12-05-2010 08:40 AM

Removing the powder coating from the mating surfaces per Vans new instructions is no problem for those who haven't hung their engine. For the 65 + who are flying, it's another issue. Anybody tried this yet?

JBPILOT 12-05-2010 09:00 AM

Mark - good point but -
 
For those of us that have had loose bolts ( most of us ), the surfaces in question have had time to work off tiny imperfections, and compress the paint to the point it is not that big an issue. If you add plenty of Loctite, and retorque them, I think they will stay put just fine. If in doubt, take one out at the next annual, and clean it and put it back in. If you keep an eye on the torque seal, and if it has stayed put, you have little to worry about. With 'blue' Loctite, you could re-do them every annual if it makes you more comfortable. Check the torque before you remove them just to see if you can detect any changes. I think everyone will find that 'blue' will satisfy this BIG problem. Lets report anything we find as we go along. If something better comes along, fine, but Loctite should give you comfort for now.

John Bender

Mich48041 12-05-2010 09:26 AM

Which came first?
 
The old saying, "Which came first, the chicken or the egg?" applies to the powder coat. Did the powder coat wear away first and thus loosened the bolts? Or did the bolts loosen first and then the moving parts wore away the powder coat? I suspect the latter. Some builders have NOT removed the powder coat and have used Loctite on the engine mounting bolts and have flown many hours without the bolts coming loose.
I agree with John Bender. Loctite will prevent the bolts from turning. It will be interesting to hear from those who are using Nord-Lock washers after a long test period. Van's service bulletin to remove powder coat and tighten to 30 foot pounds should extend the time before the bolts come out. :D
Joe

Peterk 12-05-2010 10:42 AM

Nordlocks
 
As Joe said earlier, the true testing is done in the field, not on a calculator. Like Tony and some others I too am going to use the Nordlocks without the Loctite simply because I think we need to be trying different methods and reporting back for future builders. I have nothing against Loctite, just think we need more than two people taking another path. My plane has 185 hours on it so much should be settled in. We'll see how it goes. Like Tony, I have read nothing in the tons of Nordlock info that relates to heat. Would like to see that. And of course, Rotax (and thereby Vans) will not endorse Loctite (or Nordlocks) and I can understand why. Loctite cannot be retorqued without removal and cleaning. Nordlocks have never been tried period on this engine. Thus goes the experimental aircraft business. As long as we all keep each other up to date on regular check-ups, things should be fine. My only remaining concern is for the poor slobs who build away in their garage and don't have a computer and put their bolts in with those stupid split washers. We all know where that ends up.

MartySantic 12-05-2010 11:03 AM

Quote:

Originally Posted by Peterk (Post 490951)
My only remaining concern is for the poor slobs who build away in their garage and don't have a computer and put their bolts in with those stupid split washers. We all know where that ends up.

Which brings up a question. Does Van's Aircraft consider their notification a MANDATORY change? I would certainly think that would be the case with respect to this flight critical item.

We were told MANY times during the early build process, with the multitude of REVISED plan pages that VAN'S would SPECIFICALLY state to the builder via a notification if a change was considered to be MANDATORY and REWORK is required.
This did occur with a few previous items.

I received two e-mails from Van's. The first was the FF-1207 top cooling shroud modification. The second indicating the capscrew torque should be increased to 30 ft-lbs per the ROTAX documentation, and the powder coating should be removed on the engine mount mating surface. Nowhere a hint that the retorque would most likely cure the problem and the retorque, torque seal and periodic inspection should be sufficient. (My interpretation.)

Nowhere a hint that this change was mandatory. Did I miss an e-mail?

HAS THEIR NOTIFICATION POLICY CHANGED??


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