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Old 4th Mar 2003, 16:04
  #141 (permalink)  

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Thumbs up Oh yeah, I forgot

Alkaline detergents come in two forms. Ionic and non-ionic. Ionic detergents contain free Hydroxyl (free Hydrogen) ions and Non ionic detergents do not have free Hydrogen. 99.5% or thereabouts alkaline detergents are ionic.

The free hydrogen can be absorbed by heat treated steel. The entrained hydrogen will migrate to the point of highest stress causing the item to fracture under high stress. This is called Hydrogen Embrittlement.

Alkaline detergents can also cause stress fracture on parts made of PolyCarbonate plastic. These alkaline detergents are wicked so, choose wisely.

That is why the US Military has banned them from use on aircraft.

Has the sky fallen yet? Better yet, have you seen any wolves?


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Old 4th Mar 2003, 18:29
  #142 (permalink)  

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Thumbs up Robinson and WD-40.

This is aimed at the use of WD-40 on Robinson helicopters as well as the maintenance of the helicopters painted surfaces.

Robinson does not approve WD-40 however Corrosion X aircraft grade is approved for corrosion protection. It is available in spray cans and in bulk. You can purchase an application kit and several gallons of Corrosion X for several hundred dollars.

The US Army used corrosion X in a test. Two companies of UH-60s were sent to Somalia. One group of UH-60s was aggressively treated with Corrosion X and the other group had no protection. When the two groups of helicopters were returned they were put into refurbishment. The maintenance cost on the treated helicopters was $192,000 less than the untreated ships.

Robinson also approved another Corrosion X product. The name of the product is REJEX which is used to protect the painted surfaces that get contaminated by engine exhaust and bugs.

Check out their website WWW.corrosionx.com or call them at 1-800-638-7361

Here is a partial lis of those aviation organizations using corrosion X

The Ages Group
AMR Combs
Eurocopter (Aerospatiale)
Chalks International Airways
Comair Air Academy
Confederate Air Force
Erickson Air Crane Co.
Gulfstream Aerospace Technologies
Learjet Corp.
McDonnell Douglas Helicopters
NOAA Aircraft Operations
Northrop Grumman Aircraft
Petroleum Helicopters
Raytheon Aircraft
Rockwell Collins
Saberliner Corp.
Textron Flight Service


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Old 4th Mar 2003, 20:39
  #143 (permalink)  
 
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Wow, quite a post Lu, thanks.
Anybody familiar with CarbonX? We use it (diluted) at our flight school to clean the aircraft. Corrosion is not really a problem, and the blades are just cleaned with water. Im pretty sure this stuff is made for aircraft, it would seem that this stuff is made by the same company but I didnt see anything on the website.

Just want to make sure nobody has had bad experiences caused by CarbonX.
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Old 4th Mar 2003, 21:46
  #144 (permalink)  

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Thumbs up Let me make myself clear on that point.

That should have read $192,000 per helicopter.

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Old 5th Mar 2003, 01:24
  #145 (permalink)  
 
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R 44 Helipods

I have fitted a set of helipods to a 44, they are not particularly user friendly as they don't just clip on/off. The load is useful but won't accept anything as large as a roll on case, more like a weekend bag. It does effect cruise speed but I don't remember the exact figures.
The build quality of the pods wasn't great, they were literally just a spray tank converted with a cut-out door, but it does give you a bit more flexibility for small bags or boxes. Check out www.helipod.co.nz
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Old 5th Mar 2003, 09:51
  #146 (permalink)  
 
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Could I ask the same questions as asked in the first post - but for R22's.

I've been thinking of buying a set for my 22.

My specific questions are:
1. How much calculating, weighing of baggage etc do you have to do to check your C of G when they are loaded.

2. From the web site they look like they might interfere with using the ground handling wheels. Do they or is it just the angle of the photos?

3. Do they decrease your cruise speed or increase your fuel usage to compensate and if so by how much.

4. Anyone know any names or phone numbers of users I could talk to about the above questions before I outlay the $$?

Thanks
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Old 5th Mar 2003, 11:25
  #147 (permalink)  
 
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Vorticey

I didn't ask about which surface was debonded, I'll ask the owner when I see him on Friday.
I do know that I'm buying a longer ladder so I can check the top surface as well.
The problem occurred in R44s and the AD was only for the 44 series but I think it would be prudent to be vigilant with R22 blades as well. The blades are different though (apart from their size) The R22 has alloy D spar and the R44 stainless. I don't know if they use different bonding agent but the fact that one side of the bond is different metal might make a difference. I couldn't be that lucky though

The owner keeps all the local machines at his rural property (he has a fleet of them) and he is fastidious about his machines and does most of the cleaning, washing etc himself. He's the chief pilot so he's with them all the time and the LAME is doing something with one of the machines pretty frequently.

Beyond that who could say. As far as is known they don't use it.

I hope having bare metal leading edges isn't the cause because every Robbo I've seen with over about 500 hours on the blades has no paint on the outer leading edges. Again I think it would be a case of, if that were the cause every blade here would have delaminated.


Mr. Zuckerman

Unfortunately as I said Robinson gave a very general answer to a specific question. Their reply was a page from a manual which just said automotive wax. No type or quality specified. Not much help.

Where did you get the information that Robinson do not approve the use of WD-40? I haven't been able to find that sort of specific information but if its available, officially, I would like to get it. Though they didn't say so, I got the impression from their brief reply and attachment that they weren't too keen to actually name names. Maybe again for fear that an apparent endorsment might prove to run against them if a problem ensued.
But they also did't say what you could NOT use either.

My LAME rang around operators and distributors here in OZ and came up with carnuba automotive wax. If I recall carnuba is some sort of organic oi l /wax from a tree or plant (though I am delving back into the dark recesses of my memory there.

CorrosionX doesn't seem to be available here in this part of OZ.

Now, Mr. Zuckerman, you wouldn't be trying to baffle and impress us with lots of big words would you?


Something something Meta Silicate penta hydrate - sounds a bit glassy to me.
Alkaline agents having free hydrogen Don't you mean acids have free hydrogens and alkalines accept hydrogens.
Free hydroxyl (Free Hydrogen)
MonoButyl Ether in a detergent (mmm, maybe, though the ether linkage would would render it very insoluble in ionic solution like detergent and probably defeat its purpose. If one end of the chain were a butyl what's on the opposite end of the ether bond?
Whoops, just remembered you are right...some of the short chain aromates are included in engine degreaser types to help dispersion into water when you wash off the stuff.

I take that bit back.

Ah well doesn't matter its all one up-manship isn't it.
Some of us Robbie drivers have more letters after our names than in them

Now with regard the falling sky. I do recall - I checked the posts -and that it was your good self who first saw the waxy shadow of debonding and cried that it proved the sky was falling on all users of such evil unauthorised stuff. And it was your own post which revelled in the call that WD-40 in sheeps clothing caused the problems (of course - self protected by the little insertion at the start it could be a "manufacturing anomoly" but.......)
If I recall I mentioned a few lines indicating perhaps there might be more to it, as lots of blades gets lots of WD 40 and lots of blades (in fact all except 2) don't debond every time they turn.

Now I DO agree with you that if the manufacturer doesn't endorse then we shouldn't use it. I have written back to Robinson for a more specific answer and again I'll post it when I get an answer.

Till then I'm off to buy a bigger ladder and some maybe some carnuba wax
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Old 5th Mar 2003, 12:37
  #148 (permalink)  
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Apparently they do affect the ground handling wheels, but if its as easy as advertised - 30 seconds whip on and off.............
 
Old 5th Mar 2003, 14:14
  #149 (permalink)  

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Thumbs up Yeah but....

The bit about the sky is falling and crying wolf was placed there for you the reader to exclaim and at the same time saying to yourself, ”Oh no, not again”.

The lesson in detergent chemistry was included because if I said don’t use detergents or car wax on your helicopter or on the blades you might wonder why not.

As for the helicopter manufacturer endorsing one product over another that is not the case. It is required that both military and civil airframe manufacturers test or have tested every product that is to be used on or in their respective aircraft. If it happens that two different manufacturers submit competing products and both pass the test procedures then both products can be used. In any case the manufacturer is required to include the names and / or specs of the products and publish these product names in the maintenance manual or the parts catalog for the helicopter or aircraft.

In some cases the manufacturer will assign their own spec number for a given product and not identify the product by name forcing the operator to purchase the product from them more than likely at an inflated price.

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Old 5th Mar 2003, 19:13
  #150 (permalink)  
 
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Arrow

RobboRider: Corrosion X has been available through Aviall, in spray paks or 5 litre containers.
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Old 5th Mar 2003, 20:11
  #151 (permalink)  
 
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My LAME rang around operators and distributors here in OZ and came up with carnuba automotive wax.
Be careful. Very few automotive waxes these days are primarily carnuba. Most of those with some carnuba also have cleaners of some sort in the wax. It is my impression that real carnuba wax tends to be very stiff as well and may need some heat to soften to wear it is workable.

You can get the real carnuba wax, but you have to look for it. Best bet would probably be an outfit that sells to the high-end collector or detailer.
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Old 7th Mar 2003, 08:53
  #152 (permalink)  
 
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Sprocket

I'll go to Aviall myself tomorrow then. I ran them one morning this week but the guy I spoke to said he hadn't heard of it. But you get plenty of times where you strike the wrong guy who hasn't heard of something but if you'd got one of the others the answer would have been more favourable. He tried to tell me Innox was the bee's knees but I've used that on a boat motor and I reckon it never lasted as long as the WD 40.


Speaking of answers; Try this

[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[
Dear Mr. Martin:

RHC is not aware of any debonding problems associated with any waxes or corrosion inhibitors.

With respect to waxes, use a carnuba-type wax if you ever intend to repaint your blades. Silicon-type waxes, while not prohibited, have an annoying tendency to cause "fish-eyeing" in subsequent paint applications. I do not know if the same holds true for the "modern polymeric substances" you mentioned. Also, to preclude the possibility of frictional heat buildup, do not use power tools on blades.

Regarding corrosion inhibitors, we have for may years recommended either ACF-50 or Corrosion-X, mainly because of their superior corrosion protection properties over the omnipresent WD-40. We have no objection to your continued use of WD-40, but do not spray it on Teflon-based hinges such as MR hub hinges, rod ends, tail rotor drive shaft damper pivots, governor or carb heat assist friction clutches, etc, or any rubber belts.

We are aware of debonding problems due to excessive heat from either direct (flame, or heat gun) or indirect (power tools) sources, which is why our Maintenance Manuals (MM) contain warnings to avoid heating blades above 175 degrees F. We also prohibit the use of chemical paint strippers on blades.

Presently, there is no published list of specifically approved corrosion inhibitors for our aircraft; we will incorporate such a list in a future MM revision. I am not familiar with RP-7; is the CRC product you refer to actually CRC-3.36?

Sincerely,
Patrick Cox
RHC Tech Support

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
Direct from the horses mouth.

Cheers
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Old 7th Mar 2003, 14:44
  #153 (permalink)  

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Thumbs up Pat Cox speaks.

Pat stated that they recommended that the blades never be exposed to temperatures over 175-degrees F. When I worked in Iran we had air temperatures of 113-degrees F and the ground temperature was 168-degrees F and inside the helicopters it was over 180-degrees F and it fried most of the avionics. Solar radiation is a killer and mechanical devices can soak the heat up so the local temperature (of the mechanical item) was far in excess of the local air temperature. I would assume that the two Oz Robinson’s that exhibited debonding operated in similar temperature extremes.

Lord the manufacturer of elastomeric elements on helicopters stated that if an elastomeric element were exposed to temperatures of 160-degrees F for a total period of one hour in the parts lifetime the part life expectancy (MTBF) would be cut in half.

If solar radiation was the cause of the debonding then the killer has claimed two lives (blades)


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Old 7th Mar 2003, 23:41
  #154 (permalink)  
 
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We regularly put temperature sensing tape on bearings, does this mean putting them on the blades would be a good idea???
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Old 8th Mar 2003, 00:36
  #155 (permalink)  
 
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It never gets that hot here.

We get the occasional 40 - 42 degree day (by this I mean once or twice on a bad year. ) Further west they get lots of 40 - 44 degree days in summer but never get any air temps as high as those which Lu experienced in Iran. That machine spent a lot of its time operating along the coast and closer areas so I doubt the temps it was exposed to were very high or high for very long.

The blades are out in the sun - so on those bad days the actual temp on the blades probably is very high - as high as 175 degrees? I don't know. Maybe, but as far as I know no one has measured it and published the data. Maybe thats a good little project for some engineering student. I suppose putting telatemp strips on the blades would be the easiest way find out.
But I'd be worried about one coming off in flight and unbalancing the blades.

I suspect the high temps would only apply to blades not in flight so you could probably get by without even leaving them on permanently - and having to do track and balances when they were put on. Just have to remember to take them off before starting up.

I guess again the case is - why only two blades suffering - and especially why the blade on a machine that spent most of its time at far lower temperatures down here along the coast. Why not the dozens of machines that permanently live and work in the hot climate?

I still haven't had a chance to ask the owner about which surface debonded. He didn't turn up at the aero club last night. I'll ask him when I see him.
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Old 8th Mar 2003, 00:37
  #156 (permalink)  

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Thumbs up How hot is hot?

To: Shawn Coyle


I don’t believe it would stick. However there are handheld infra red sensors similar to what a doctor sticks in your ear to take your temperature that could be used for this purpose.

My intro reads How hot is hot and here is an example. We landed our aircraft at Corey Field an outlying field at Pensacola during the summer. Our aircraft was on the ground for about five minutes when I was approached. I was told that the base order was that on a three blade prop one blade must be up and the other two down. I climbed up and onto the wing and the skin was already over 160-degrees F and getting hotter. My feet and skin were burning and in trying to hand move the prop a gas pocket caused the prop to rotate. I almost fell off the wing and by the time I got down my butt, my feet and my hands were burnt. I told the guy to screw the base order or to do it himself. Anyone that has pulled maintenance under similar conditions will know what I am talking about..


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Old 8th Mar 2003, 00:38
  #157 (permalink)  
 
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robborider

what are you going to carrie in them, foam?

i wonder do the skids need reinforcing, the manual states nothing can be attached to them.
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Old 8th Mar 2003, 07:48
  #158 (permalink)  
 
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The distributer told me they are approved for 46 lbs if you are using one or 100 lbs each if you are using both.

I think their actual attachment point is on the bottom frame rather than the skid, but I may be wrong there cos I haven't actually seen a set in the flesh.

Obviously that weight is part of your all up max weight so it is just redistributing what you are going to carry.
But then I do a lot of trips where: me plus son plus camping gear is below max weight but above the volume that is comfortable in the cabin.

But if the Vne is dropped I'm not that keen cos on our Secret Mens Business (see http://secretmensbusiness.homestead.com )trips I'm trying to keep up with a squadron of fixed wingers who are TAS-ing about 100 - 105 kts. While I'm TAS-ing at 90 the separation is good but if it dropped me down to say 80 kts it starts making me too far behind.
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Old 10th Mar 2003, 02:34
  #159 (permalink)  
 
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i have heard from a reliable source that both the blades had
delaminated, how bizarre is that.
one blade was a very small section but the blade that failed the most had delaminated from the tip and in one metre. the laminate had peeled back.

it is not known yet where the delamination started.
the main delamination occured at the spar in front of the trim tab.

i also heard that the pilot had full throttle with the collective fully down and only just maintaining rpm because of the drag.

i am sure that the pilot would not have been able to see properly with the huge ammount of vibration present. he was extremely lucky to get it near the ground but unfortunately they hit a wire. the pilot suffered minor spinal injuries but is ok and the passenger is back at work.

the blades have gone back to the usa, to franks.
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Old 10th Mar 2003, 08:38
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Imabell: It sounds like these guys were lucky to survive. I did hear last week that the wire may have slowed their descent but that was probably only rumour.

Obviously a full auto was out of the question.

RobboRider: Corrosion X (MIL-C-81309E) part number for aerosol cans is 80102 and 84004 for gallon container.
Sometimes you get a better response from the suppliers when you give them a part number.
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