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Posted

It seems the sierras are a solid design, CASA hasn't said anything against it. I read somewhere that this plane is too light on pitch (lighter than most kit builds). Has anyone flown both the rv12 and sierra?

 

 

Posted

We are lucky that we didn't have to wait for blokes like Lawrence Hargrave, Octave Chanute, Otto Lillienthal, Wilbur and Orville, Glenn Curtis and a host of others to complete their aeronautical engineering degrees.

 

The airplane involved in the incident with the ferris wheel is probably unique. I've yet to see conclusive proof that it was actually constructed in Morgan's factory. Where is the proof that the fuel line was fitted in that way by Morgan? Fuel filters have to be changed as part of regular maintenance. Who is to say that someone has been lazy when they last changed this one?

 

Every airplane we operate is built and maintained with a "she'll be right, mate!" attitude. It just depends on the person involved where on the descending scale from 'near perfection' to "how'd you get away with that?" the expression of the attitude falls.

 

OME

 

 

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Guest asmol
Posted

Tongue in cheek!

 

I thought it was only ostriches than had their heads in the sand, not Emu's, Old Man Emu ?

 

Anyway i understood CASA validated the questionable building problems by stopping the company building factory built aircraft and from now onwards they can only sell kits unless they DEMONSTRATE compliance with ASTM/LSA standards. That's the way i understood the report and fallout.

 

I do agree not every plane ever built needs to be certified or built by engineers BUT the buyer or pilot/passengers needs to be at least made aware of these facts. Would something else have taken out the ferris wheel plane in the future like a control stick coming off because of the bodgy job, or the wires attached to the fuel lines wearing through and catching fire, who knows. I just know my partner wont let me buy a plane while the media is full of accidents every week as front page news. She forgets that i ride my V Max to the airport to look around and almost every trip come close to death also.

 

 

Posted
I thought it was only ostriches than had their heads in the sand, not Emu's, Old Man Emu ?

Head in the sand? This is the way I'm looking at it:

 

meerkat.jpg.62c80cd51b342a48ed579d2d670fe32f.jpg

 

OME

 

 

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Posted

Very small diameters are not suited for worm drive hose clips (re fuel lines) They distort and may cause a leak. The "barb"on the inner fitting should resist the fuel line coming off. Often the rubber has to be cut lengthwise to get the fuel line off when it's been there a while. Zip ties?? I don't like the look of them but it's possible they would pass a pull off test if the design of the tie was good. Like all things thetywould have a "life", (as the fuel lines do).

 

Nyloc nuts are OK in some places where no heat is likely to affect them. You can't re use them indefinitely and the thread they go on has to be undamaged, and the correct number of threads sticking through. Nev

 

 

Posted

The best fuel line clamps IMHO are Norma Cobra clamps which are one piece stainless steel hose clamps that don't come undone & are very low profile with no bits poking out to catch anything. They are removable and re-usable. They are made specifically for the diameter of hose you have. I have used these exclusively in my build. There are special pliers for installation & removal but you don't need them as a good set of ordinary pliers and a fine point screwdriver to aid in removal is all that is needed. See http://normapacific.com/Listing/Products+-+Hose+Clamps/NORMACLAMP%AE+Cobra+One+Piece+Hose+Clips

 

 

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Posted
Head in the sand? This is the way I'm looking at it:[ATTACH=full]35662[/ATTACH]

 

OME

Love the photo of a Meerkat tail dragger. 014_spot_on.gif.1f3bdf64e5eb969e67a583c9d350cd1f.gif

Alan.

 

 

Posted
Thanks guys.Kaz

It's true Kaz, I'm married to a Lawyer and she's always screwing me.

 

 

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Posted
Skiting eh? You are probably living off her earnings too I suppose. Nev

Could do (as she could off mine) but no, I'm one of those sexist bastards who believes it's the man's prerogative to slay the beast and drag it home for the woman to clean and cook it.

 

 

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Posted
It's true Kaz, I'm married to a Lawyer and she's always screwing me.

How much do you have to pay?; I thought they were very expensive.

 

 

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Posted
How much do you have to pay?; I thought they were very expensive.

I married her, i.e. I paid the ultimate price, with my life.

 

 

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Posted

So you are posting this humorously. (if you paid with your life), post humously. Most only lose their freedom when they sign up. Nev

 

 

Posted
yes, but a financial advisor is more of a salesman for financial products, nothing more.. you will find degree qualified economists and the like designing said products...

Now this worries me...

 

really? used to be common practice to use Zip ties instead of proper hose clamps? i have never seen a zip ties as a hose clamp, ever, anywhere. not even in a goKart.

I can assure you that they were common place in early ultralights and still being used. If you doubt their effectiveness get a piece of hose worm drive clip on one end and cable tie on the other and pressure test until one leaks, you will be surprised. Then replace the worm drive which failed with a cable tie and increase the pressure until the something breaks you will be surprised. Then throw away the piece of broken fuel hose.

 

 

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Posted

RAA should issue an immediate requirement to remove these items from fuel line assemblies.

 

These are actually cable ties, designed for the realively low tension job of bundle electrical wiring into a "harness"

 

Sure we've adapted them for many other uses, usually associated with tidying things up.

 

However, their achilles heel is that the plastic or nylon deteriorates in a relatievly short time; I've had them fail in agricultural use where there was sunlight in less than one summer period.

 

The secondary problem around fuel lines is that in the case of a fire they usually perform at around Z-2 standard which says:

 

  • They may not burn for more than 30 seconds (in tension, as in being used as a hose clamp, elasticity will begin immediately, and a hose under pressure can be pushed off, providing a major fire fuel source.
     
     
  • Specimens are allowed to drip flaming particles, so if you are using them in the engine bay, instead of a small fire burning out, they can ignite other areas.
     
     

 

 

Forget about the clowns who have been using them; DON'T EVEN THINK ABOUT IT!

 

 

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Posted

30 seconds in a fuel fire, hmmm, don't think cable ties come into the equation.

 

 

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Posted

Afuel fire can be caused by a cable tie perishing and cracking and in that case its fire properties are secondary, but most fires are electrical or due to oil being spilled or an oil line failing. The fire may only be smouldering. Im those cases you will have been trained in how to manage the aircraft down to the ground, including assymetrical flight to keep flames to one side. If a cable tie softens or elasticises THEN you have the big fuel fire.

 

 

  • Caution 1
Posted

A fuel fire can be caused by an a engine failure, an electrical failure, a hose clamp failure, a fuel pump failure, a crash landing failure, a fuel hose failure. And?

 

 

Posted

....and a steel clamp cannot catch fire and doesn't perish due to oil, heat or sunlight.

 

I've been through the steel clamp issue that Facthunter mentioned, and went over to the thin stainless steel type, and the overlap issue doesn't occur there.

 

The stainless steel hose clamps are petty cash.

 

However, and someone mentioned earlier there are even better ones.

 

 

Posted

Yep sure is, and? I really do wonder if you fly cause it seems a bit to dangerous for you.

 

 

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Posted

IF you are serious about engine fires we would pay more attention to isolating fuel and oil and a better firewall. We have a lot of pressured oil lines on a lot of motors and oil coolers which can fail. ALL this stuff needs inspection and maintenance. Your oil and fuel lines should be replaced regularly, long before they show evidence of deterioration , and use quality components. Nev

 

 

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Posted
Yep sure is, and? I really do wonder if you fly cause it seems a bit to dangerous for you.

Yes I do, and no it doesn't; and any thinking person will understand the safety advantage of a steel clamp.

 

 

Posted

Sometimes these things are not as obvious as they seem. The main thing with hoses is the hose quality, and the raised bit you push it over. A plain pipe is not safe , no matter what the clamp unless a strip goes to a fixed point to anchor the clamp and prevent it coming adrift. Nev

 

 

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