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Heads up elevator failure JetLegent Hawk

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Old 12-01-2011, 03:27 PM
  #26
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: YellowAircraft

Hi,

Post after post; thread after thread. Same problems. Same results. Why, oh why do these guys get away with this? Wait... I know... because we keep buying.

We (the jet-modelling community) should formulate and sign an electronic petition and deliver it to every major overseas manufacturer of jet-powered ARFs. The notice should basically state that from now on, a detailed, progressive photo-documentation of the installation/fabrication of the critical structures (that we can't see without an x-ray) is considered a basic, REQUIRED item and we want it in the box with the ARF. When they get ready to glue that top skin onto the wings and stabs, they take a pic first. When they get ready to close up the area that contains the stab shaft, they take a pic of the anti-rotation pin in all its structurally adequate glory FIRST. Same with the gear mounts, etc. It won't cost them more than a few extra minutes during the construction and a few pages of color copying. Heck, we can even stipulate that they may jack the price up five or ten bucks to cover that (as it's a small price to pay for a little extra peace-of-mind).

This way, if you were interested in ARF ''X'', you could ask for an emailed file with those pics and know BEFORE you buy that there's glue on your ribs/spars and that your shaft isn't going to crack a glue joint and start rotating in the stab. If we, the end-users, collectively demand that, then wouldn't that motivate them to build it properly?

Just a thought...
Shawn,I like that idea.Not a perfect solution but a step in the right direction.If a jet went down,.. and the crash damage did not reflect the pictured construction as k-son has suggested.That would be fraud and that MFG(X) would be toast period.Pictures would give some idea and piece of mind to what is under the skin.
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Old 12-01-2011, 03:37 PM
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: rhklenke


Quote:
ORIGINAL: dubd

Not saying CARF is perfect, no company (regardless of industry) is, but the perception is that they have much higher standards than other ARF companies. I don't think that is by accident.
Agreed. I don't think though that the pictures that they provide are enough to prove that their structure is sufficient and I'm not sure that even pictures to the level that Sean suggests is enough.

Bob

True,

But at least you have a better idea what you're buying! When you buy an ARF with a full-flying stab, you have no idea what's going on in there. If they provided you a picture of what's in there...particularly if they provided that in advance...then you'd be far better informed as a consumer. If you don't like how they built it, you don't buy it. If all these people who post these horror stories had seen the messes they bought in advance, I don't imagine they would have bought. When you put your $5k worth of gear into an ARF, you'd like to know what's cooking under the hood. I don't see the drawbacks...
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Old 12-01-2011, 04:00 PM
  #28
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Default RE: Heads up elevator failure JetLegent Hawk

so if they put the time into it to make it right.. IT COSTS TOO MUCH....

make it cheap so people will buy it... inferior quality...  YOU WONDER WHY...

no different from all the other rc groups....
 

you just loose 5000.00 turbines and  get a thinner wallet. 
but keep complaining, and then we can have annuals on turbine powered aircraft, faa inspections, more waivers, ans so on.

i guess it goes back to " don't fly more than you can afford to lose"



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Old 12-01-2011, 04:42 PM
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: k_sonn

How would you know for sure if the pictures sent are of the same airframe you were purchasing?

The only real way to have piece of mind is to build the plane yourself.

Kirk

Kirkasked the samequestion I was going to, AlsoI think these companies need to step up and stand behind their products
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Old 12-01-2011, 04:54 PM
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Default RE: Heads up elevator failure JetLegent Hawk

Based on what I am getting from this thread, the JL T-45 has been out for years and the problem is not new; however, people are buying the plane anyways. Given that, I don't see why the manufacturer would bother resolving the issue.
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Old 12-01-2011, 04:57 PM
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Default RE: Heads up elevator failure JetLegent Hawk

My T-45 almost suffered the same fate.... I'ts possible that the problem I discovered with mine, could have happened to him.

Check out post #1130.

http://www.rcuniverse.com/forum/m_49...46/key_/tm.htm
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Old 12-01-2011, 08:38 PM
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Default RE: Heads up elevator failure JetLegent Hawk

My condolences to the owner.

The problem with the Chinese manufacturers is that there is no quality control at all. If you buy a kit its a raffle. Some people get good kits, with no problems, others get ones with defects.
In the defence of the manufacturers(not saying this is the case here), sometimes we, the modellers exceed the limitations of the airframe by putting larger turbines, servos and generally adding to the wing loading.

What worries me the most is the parts of the model, i.e wings and stabilisers which you cant see into. In many crashed models we witnessed sheeting not glued onto ribs, spot gluing of ribs or spars etc. I dont think people are expected to spend money on such kits only to have to drill holes in the airframe to inspect "what lies beneath".
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Old 12-01-2011, 09:26 PM
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: dubd

Based on what I am getting from this thread, the JL T-45 has been out for years and the problem is not new; however, people are buying the plane anyways. Given that, I don't see why the manufacturer would bother resolving the issue.

Exactafreakinmente.
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Old 12-01-2011, 09:30 PM
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Default RE: Heads up elevator failure JetLegent Hawk

Hi,

So follow my idea through to the end. The point isn't just the pics themselves, it's that they have to be accountable for what's under the skin even in just this small way. If you know your buyers expect, at a minimum, to see what's going on inside before they buy, then aren't you going to be a little more careful with what's going on inside? Either way, if you're not satisfied with the internal structure.....YOU DON'T BUY. That's built-in accountability right there.
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Old 12-01-2011, 09:33 PM
  #35
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Default RE: Heads up elevator failure JetLegent Hawk

When parts are put into humans (metal, plastic etc.) they all have serial numbers for tracing. It seems to me the model manf. could do the same thing on the pins and shafts and such. this would also block the problem that K-Sonn brought up
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Old 12-01-2011, 11:06 PM
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: SKYPILOT

When parts are put into humans (metal, plastic etc.) they all have serial numbers for tracing. It seems to me the model manf. could do the same thing on the pins and shafts and such. this would also block the problem that K-Sonn brought up
I dont really see where having sn's on the parts would really help, If you bought a jet legend you already know that Jet legend should stand behind it's products
and JL knows where the parts they use or sourced from. Bottom line if a company want to build a quality product they will if not having a picture or sn wont
do anything IMO.
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Old 12-02-2011, 04:57 AM
  #37
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Default RE: Heads up elevator failure JetLegent Hawk

Has this issue been clearly communicated to the manufacturer? What has been their response? I believe that any upfront company interested in it's reputation, delivering value, and fostering a loyal consumer base would react to improve inadequacies brought to light by consumers. If a change needs to made in the field then a directive should be sent out or posted on their website. At a minimum they have a record of the first point of sale of the model. If a component needs changing then perhaps they offer a resonable warranty period (say 6 months) and within that time the part is replaced, beyond that it can be offered to the owner at an 'at cost' price.
Having said that and they still refuse to acknowledge the issue, then it's really up to the consumer whether they feel that buying a product from them gives the associated support expected with your purchase. If not, then this isn't the right supplier for you. As noted earlier, we're the client and we have the final say on where our hobby budgets are spent. If we feel that the product/service doesn't warrant the cost then mfg will quickly get that message.
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Old 12-02-2011, 05:04 AM
  #38
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Default RE: Heads up elevator failure JetLegent Hawk

removed comment....you boys have fun now!
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Old 12-02-2011, 05:33 AM
  #39
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Default RE: Heads up elevator failure JetLegent Hawk

my mate paid alot of money for a edge 540 from carf and the way that they glued the under carrage in is a joke. Practidby (sorry for bad spelling) came out at first landing. The landing was very soft no bounce no thud anything it torn the aircrft and put holes in the wings. my prides himself on his landings. he also has a ultra lightning from them and not sure of the quality build by carf any more because of the poor quality of workmanship by carf ie lack of glue for a start. now my mate has fixed the u/c problem with carbon fibre and good epoxy which is the way it should have been done in the first place.. to me they should stop using the hot glue gun and cheap glue and materials on a/c which are supposed to be high quality
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Old 12-02-2011, 06:23 AM
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Default RE: Heads up elevator failure JetLegent Hawk

I've owned a 40% CARF Extra 260 and SuperXtra and the landing gear area was built like a tank. Sounds like that they went backwards on the Edge.
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Old 12-02-2011, 06:40 AM
  #41
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: smchale

Has this issue been clearly communicated to the manufacturer? What has been their response? I believe that any upfront company interested in it's reputation, delivering value, and fostering a loyal consumer base would react to improve inadequacies brought to light by consumers. If a change needs to made in the field then a directive should be sent out or posted on their website. At a minimum they have a record of the first point of sale of the model. If a component needs changing then perhaps they offer a resonable warranty period (say 6 months) and within that time the part is replaced, beyond that it can be offered to the owner at an 'at cost' price.
Having said that and they still refuse to acknowledge the issue, then it's really up to the consumer whether they feel that buying a product from them gives the associated support expected with your purchase. If not, then this isn't the right supplier for you. As noted earlier, we're the client and we have the final say on where our hobby budgets are spent. If we feel that the product/service doesn't warrant the cost then mfg will quickly get that message.
I did send an email to the manufacturer and I am waiting for there answer I will keep you posted of the results.
This is a thread about the elevator failure of the jetlegend jet please try to keep this thread clean, the problems of the other manufacturers are not a subject of this thread.
Thank you
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Old 12-02-2011, 07:06 AM
  #42
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Default RE: Heads up elevator failure JetLegent Hawk

My theory: (IĀ“ll try to make the story short, and hope it will help)

In this case, no matter how well inspected/ constructed the stabs and pivot hardware are. If the stab is mounted in a aerodinamically unstable pivot position, it may fail and this is speed related, no matter how strong your servos are or robust your linkage.

Seems that the JL F-20, Big F-15 and Hawk/T45 have crashed due to elevator issues, unlikeĀ“s JL small F-15, F-18 and F-16, wich are built in the same way, by the same people and materials.

Just as a example compare the pivot points in the Hawk stab and in their F-18/16 in relation to the main aerodynamic chord of the stab (MAC). I would suggest to JL for the third time (and probably last) to take special attention to this issue, in their own best interest, as well the safety interest of the JL jet owners.


Best regards, Enrique.


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Old 12-02-2011, 08:05 AM
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: tp777fo

removed comment....you boys have fun now!
that comment ?
http://www.rcuniverse.com/forum/m_95.../anchor/tm.htm
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Old 12-02-2011, 08:06 AM
  #44
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Default RE: Heads up elevator failure JetLegent Hawk

So in the thread George highlighted about the potential wing problem, Mike posted here:

http://www.rcuniverse.com/forum/m_10...ection/tm.htm#

It specifically warns about the pins breaking the stabs. Did you do anything about it?

PaulD
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Old 12-02-2011, 08:08 AM
  #45
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Default RE: Heads up elevator failure JetLegent Hawk

I'm really surprised this post is still up. Jet Legend is one of the "approved by the real jet guys on RCU" companies. They and their friends must not have seen this yet.
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Old 12-02-2011, 08:09 AM
  #46
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: erbroens

My theory: (IĀ“ll try to make the story short, and hope it will help)

In this case, no matter how well inspected/ constructed the stabs and pivot hardware are. If the stab is mounted in a aerodinamically unstable pivot position, it may fail and this is speed related, no matter how strong your servos are or robust your linkage.

Seems that the JL F-20, Big F-15 and Hawk/T45 have crashed due to elevator issues, unlikeĀ“s JL small F-15, F-18 and F-16, wich are built in the same way, by the same people and materials.

Just as a example compare the pivot points in the Hawk stab and in their F-18/16 in relation to the main aerodynamic chord of the stab (MAC). I would suggest to JL for the third time (and probably last) to take special attention to this issue, in their own best interest, as well the safety interest of the JL jet owners.


Best regards, Enrique.



Hi,

We're supposing (quite incorrectly IMO) that these guys know anything at all about MAC or any other aeronautical design principles. It's more like "Splish Splash" and TLAR. If, for example, the stab shaft didn't fit in the right spot on the chord (because of the thickness of the stab or the diameter of the shaft), they'd just move it without a second thought.

Construction shots of critical structures should be part of every all-composite ARF shipped from overseas. Think about it...that would give the buyer a little peace-of-mind and the seller a reason to take a minute and make sure they do it right.
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Old 12-02-2011, 08:16 AM
  #47
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Default RE: Heads up elevator failure JetLegent Hawk

If you are worrying about critical structure failures, rather than photographing or x-raying an arf, why not just build it yourself? I have built all of my own planes, never had a problem. Not knocking arf's, just wondering.
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Old 12-02-2011, 08:35 AM
  #48
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Default RE: Heads up elevator failure JetLegent Hawk

My Jet Legend T45 now has 110+ flights and no apparant problem with position of pivot and MAC.

Paul S
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Old 12-02-2011, 08:39 AM
  #49
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Default RE: Heads up elevator failure JetLegent Hawk

Pics would help, yes. But it is not the only solution.


Perhaps some brave manufaturer should attach some of this airplane parts in a fast car rooftop and do some runs as a QC program and windtunnel test, pretty much like Rusjet did on his YAK.


At least they would be able to say us the certified Vne of a particular plane.

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Old 12-02-2011, 09:03 AM
  #50
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Default RE: Heads up elevator failure JetLegent Hawk


Quote:
ORIGINAL: paulsf86

My Jet Legend T45 now has 110+ flights and no apparant problem with position of pivot and MAC.

Paul S
Among with yours, there are many other T45Ā“s flying ok after dozens of flights, but there are many variables like the slop and quality of the servo linkages installed, the kind of servos used, the rigidity of the fiberglass work on the stab, the engine thrust and escape velocity of the gases , how the throttle is managed, altitude, heat, air density, turbulence,wear in the pivot mechanism, etc that can start a self destructing sequence on flight #1 or flight #111.


What is a fact for example is that a local recently lost his Hawk in the first flights. He was using a 31 pound thrust JC Cheetah. His stab simply broke in half when he started to fly it more enthusiastically.. never saw this guy losing a jet before this.

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