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Morgan Sierra safety

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

I think that the issue is that a small fire melts the cable tie and it then becomes a big fuel fire.....

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Your carburetter is a source of possible fuel leakage. All you need is a faulty float or grunge under the needle or overpressure from the auxiliary fuel pump. Pressurised fuel lines should consider upgraded fittings rather than push on and clamp. Horses for courses. Nev

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The fuel didnt leak from a hose that came off, cable ties are one of the best ties just look at a out board motor tank. The fuel filter was NOT forward of the fire wall as stated. The fuel tank split open. The 747 has wires inside the fuel tank, there is no safety issue with tiring a wire to a fuel proof line to stop it vibiriting, this was removed ,but it will brake with vibrating. there was no shafing of the trim bungee this was made up.the stick yes some one in the work shop has not done a good job here . Have a good look at a piper of such and you can find fault with anything. The reason it never passed the second time we did all the paper work by our tech guy the first thing he said my plane hit a ferris wheel. and then condemned ever thing we had done, no through of how much time and money a small business has put in. Also the guys did walk away and not taken away . I get abusive calls and mail that it flew into a hole, but i can tell you that is not the case ,it took out the two main outer supports and two gondoliers. A 22G main fuse stayed together.So if you think it a crap aircraft you had better take a closer look at the imported craft. Your aussie designed aircraft are going to come out better in a crash.

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You are in "wheel" trouble with CASA if you hit a Ferris wheel. It's something you don't get over easily.. Many others don't get the opportunity to hit one and become famous. Mostly Ferris wheels aren't put in stupid places, near where planes fly.. Nev

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It is interesting to note that the damaged Sierra was repaired and lived to fly again....I bet my Cessna 150 wouldn't have.

Alan.

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A Cessna 150 is pretty tough. They have proven themselves over the years. Nev

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

 

Here fishy fishy fishy.

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Going back to the actual Morgan design....what do others (including builders) think of pop rivets going into FRP ribs? Is the fibreglass strong enough to hold a rivet over time...especially with the uneven temperature expansion/contraction of the metal skin over the plastic ribs?

 

Also, the stabilator appears to have all the FRP ribs epoxied to a single metal torque tube (is that the right term?). Again, it seems to me in the long term that epoxy might lose adhesion to the metal due to uneven expansion/contraction. Of all the joints in a plane they are the ones I would most hate to fail. Comments?

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As long as you use a washer behind the rivet and epoxy the rib to the skin it should ok

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Epoxy shrinks as it cures and also shrinks a small amount over time so the grip on the roughened tube is very good. I did a test piece on a tube and could not get it to separate.

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what do others (including builders) think of pop rivets going into FRP ribs? Is the fibreglass strong enough to hold a rivet over time...

 

Yes, no problem. I have rebuilt a number of '60's and 70's Ossa, Montesa, Bultaco and the odd 1960's Rickman that have a number of riveted fiberglass parts in a vibrating, stressful situation and none were an issue after 30 to 40 years. Done some fiberglass kitcar stuff as well using rivets for various things.

 

 

Also, the stabilator appears to have all the FRP ribs epoxied to a single metal torque tube (is that the right term?). Again, it seems to me in the long term that epoxy might lose adhesion to the metal due to uneven expansion/contraction.

 

Correct and probably not ideal, not because of contraction etc, but simply because fiberglass doesn't bond to metal permanently and one day it will separate, that's a given, the question is "when", not "if". That could be 100 years but I still don't like those odds.

 

There's 6 ribs per side, after glassing as per instruction, pop a rivet in the second and third from the outside on the vertical face facing the rear (where the tube is in compression), and 4 rivets equally around the circumference on the outside one (number 6). Do not rivet the inside 3. That will be enough.

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There are cable ties and cable ties. Good quality nylon cable ties will outlast the rubberised fuel line that they are constricting and so long as they are not exposed to ultraviolet radiation, as stated by others they are better than hose clips. ATSB were looking for anything they could find to assign blame. The same as whinging about an electrical cable being cable tied to a fuel line. As Garry pointed out there are electrical cables routed inside fuel tanks in many aircraft.

 

The fibreglass ribs have a CSM base with a roving cap around the rivet face circumference. The rivets are very solid in this substrate. I suspect that Bex's use on motorbikes had perhaps thicker glass but less extensive reinforcement.

 

I have no concern with the glass to alloy tube assembly of the stabilator. Glass does not stick well to a smooth alloy surface but rough it sufficiently and it won't separate.

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The fiberglass rib will still be in one piece long after a metal rib has cracked and fallen out over time. only the Cheetah rear rib that has more load on it we use metal washers.

The tail spar roughen up to attach the glass rib, the glass is always shrinking to the tube and making the bond tighter over time. its not going anywhere, and vibration is not going to have any effect over time. its the best of all worlds.

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The tail spar roughen up to attach the glass rib, the glass is always shrinking to the tube and making the bond tighter over time. its not going anywhere, and vibration is not going to have any effect over time. its the best of all worlds.

 

Yes it's a good application of FRP which shrinks around an object. Have used it for large steel outlet couplings on fuel tankers and fire crash tenders.

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any rivet through fibreglass should have a washer under its head, and definitely under its tail. even bucked solid rivets.

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The tail spar roughen up to attach the glass rib, the glass is always shrinking to the tube and making the bond tighter over time. its not going anywhere, and vibration is not going to have any effect over time. its the best of all worlds.

 

Sure Fiberglass is asymptotic, but it's main shrinkage takes place over the first week or 2 and the shrinkage is not greater than it's expandable range due to heat. Not my opinion, scientific fact.

 

Fiberglass does not permanently bond to metal, roughened or not, and again, not my opinion, that's factual science. The joint will eventually fail, go ask 3M, Selleys, Cyberbond or someone similar.

 

Besides just knowing how poorly metal and fiberglass bonds from many years of playing with the stuff and that's it's veritable lore (for a change), I did a whole series of dedicated coupon and other testing last year including fiberglass and a range of expensive epoxys. Here is some of those tests, some Morgan builders might recognise the offcuts in the video ....

 

th_liquidnails_zpsd7da0b2a.mp4

 

epoxy.thumb.jpg.8288bc1c6bda7c47463ddf8e0dc7ee3a.jpg

 

All tests failed to be considered as a standalone joint, fiberglass easily one of the weakest. Surprisingly, common hardware store "Liquid Nails" type was consistently one of the best and is actually the video above.

 

Anyway, not here for a fight, I was asked the question and I answered. If you choose to fly with the standard setup, that's your prerogative, I won't and for the addition of 5 minutes work and a couple of rivets I don't see why anyone wouldn't support that.

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In flying IF there's any doubt, try and make it NO doubt. Testing assemblies as a sample relies on the assumption the variation on quality is small. The Fokker F27 was redux bonded.( Thermosetting I believe) The Fairchild version was riveted . Later....More fatigue without the glue. but that's another aspect..Nev

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Sounds like you'll be flogging China made Morgan ....

 

That would involve the theft of someone's else's hard work and intellect (registered or not), not something I do.

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Not if you had approval, license or whatever....

 

I offer you a categorical assurance of "No".

 

I simply needed an easily modifiable plane to test some ideas and conduct some engine experiments with and I didn't have time to scratch build my own - and as always, I chose to spend my money in Oz.

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I offer you a categorical assurance of "No".

 

I simply needed an easily modifiable plane to test some ideas and conduct some engine experiments with and I didn't have time to scratch build my own - and as always, I chose to spend my money in Oz.

 

I'm definitely not saying there is anything wrong with doing it. Might even be a good thing.

I'm not a China basher....... It's simply the manufacturer to the world.....

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I'm definitely not saying there is anything wrong with doing it. Might even be a good thing.

I'm not a China basher....... It's simply the manufacturer to the world.....

 

No problem, I wasn't referencing it towards China nor did I take your comments as me possibly doing it that way because I'm in China, I just don't believe in the theft of other's hard earn't IPR (intellectual property rights or patents, legally registered or not) regardless of where I am at.

 

I'm definitely not saying there is anything wrong with doing it. Might even be a good thing.

 

I had the idea some years ago and I contacted every Australian aircraft company I could find including digging up dead ones. Spoke or visited them all bar one. With the exception of none, all have some serious delusions of how awesome they are pertaining to their worth and or product, the levels vary of course from genuine pride in themselves, understandable, to the one guy who thinks his business is worth triple the total value of his entire retail sales for the last 20 years.

 

So yeah, nah, I'll pass thanks.

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Fiberglass does not permanently bond to metal, roughened or not, and again, not my opinion, that's factual science. The joint will eventually fail, go ask 3M, Selleys, Cyberbond or someone similar.

 

That is correct, but we were talking about FRP being laid in such a way that when it shrinks it locks on to mutilated steep and the mutilations - grooves and protrusions provide a mechanical lock.

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That is correct, but we were talking about FRP being laid in such a way that when it shrinks it locks on to mutilated steep and the mutilations - grooves and protrusions provide a mechanical lock.

 

Oh I understand exactly what's being proffered. After the bond has broken, over time the back and forwards movement will grind it smooth and eventually slip around.

 

Sure, that may be 100 years and millions of cycles ..... but maybe not. Who knows, you guys are only guessing and you have no empirical evidence available, that's the problem. You may have sealed up some static pipes, but this joint has constant cyclic shear stress applied along with constant expansion/contraction at different material rates trying to tear it apart - even when it's just sitting.

 

I've stated the plane is very safe and crashworthy so I'm obviously in support of the design overall and I have promoted the Morgan to individuals ho ask and in the HBA forum. I'm not here to cause drama and panic, but this bit is simply not up to my standard and it's technically not a good idea, as well as the fuel tank construction being too thin considering it's in the cockpit. A couple of simple rivets fixes this issue, lay up the tank thicker or replace it (as Sloper did) fixes the other. Minor, but important fixes.

 

It's not law to build to the original specs, that's only a guide, once the kit is in your possession it's up to you.

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