tamjets

My Feedback: (2)

Here what I see with this set up was wrong. If you had this lingkage set up. I bet on anything it will flutter. Regardless which manufactures making the jets.
If you don't want your plane to be next hot topic.
Get it done right.
At least this resolve one of the linkage flutter problem.

AFTERBURNER1

My Feedback: (80)

+ 1

ravill

My Feedback: (11)

BVM makes EXACTLY 8 scale jets.

1. "little" F-86
2. "Big" f-86
3. t-33
4. f-80
5. Mig-15
6. F-4 Phantom
7. F-100D
8. F-100F

Not to mention all the scale jets Comp ARF or Skymaster makes with a steadfast reputation.

Take your pick and stop endangering our hobby.

I'm at the point of taking personal offense to YOUR (and everyone else who continues to fly FEJ) moronic, lackadaisical and ignorant approach to what has proved, over and over and over again, to be unsafe airframes. These flying paper mache "jets" will kill someone and take my beloved RC Jet hobby away from me. And yes, I will take it personally.

To the OP, great save! Time to take all the stuff out of that airplane and put it into a safe airplane. Lesson learned huh?!

ravill

My Feedback: (11)

-1

dubd

-10000

tamjets

My Feedback: (2)

-001

gunradd

My Feedback: (9)

Tam here are a few pics of what they use now. They use a shaft driven from the servo directly into the elevator. This will put an insane load onto the servo topcase and bearing. Its a total joke and will cause the servo to wear out very fast. To make matters worse the servo gets installed from the backside pushing it even further from the flight control it self putting an even greater load onto it.

rcjets_63

My Feedback: (4)

Indeed, the jet was shipped with the FEJ direct drive system on the H-stabs. It fluttered during the maiden flight. FEJ then supplied the Lukey with a new H-stab setup with an aluminum plate for two 8711 servos. This was further reinforced with maple rails and installed. It lasted 4 flights.

FEJ replaced one poor design and inadequate parts with another poor design and inadequate parts.

As for the issue of grounding honeycomb planes based on two jets that have "allegedly" had structural failure, there is no "allegedly" about it (the videos prove that, unless you are some conspiracy theorist and think the videos were CGI'd or doctored in some way. Also, it's not just two jets, it's far more than that. For instance, here is a link to a video of the 5/19/10 maiden flight of a 1/5 scale FEJ F-18. This plane experienced severe rudder flutter and H-stab flutter on it's first flight. Please watch the last 5 seconds of the video to see how the H-stab is flopping around. This certainly looks familiar to what we see in Boli's video. In three years it looks like very little has changed.

There are three facets that need to come together to have an airworthy H-stab setup:
1) Proper aerodynamics - the pivot point on the H-stab needs to be in the correct position to prevent the onset of flutter. The forces generated by flutter can rip apart even the strongest design. We continue to see FEJ stabs with incorrectly placed pivots.
2) Proper linkage - as seen in other threads, the FEJ direct drive system places high twisting loads on the servo output arm, loads which the servo was not designed to withstand. We've seen improper linkages set up per factory photos which have exasperated the situation and led to the early onset of flutter.
3) Proper and sufficient structure - FEJ has shown in photos in other threads (e.g. the F-14 crash thread) inadequate structure and incorrect use of honeycomb material.

These issues are only exasperated as the aircraft gets larger and the strength/design margins get smaller. FEJ makes their large jets out of honeycomb. They aren't all necessarily bad, but some of them have fundemental flaws that present a real safety hazard.

And we have the pom-pom crew that seem outraged at the notion of FEJ honeycomb jets be grounded. There is a clear record here of issues (see 1-3 above) dating back for years. What I don't understand is why you wouldn't voluntarily ground the planes yourself. If I had $15K-$20K wrapped up in a plane and there was the mere suggestion of a hidden flaw, there is no way it would leave the ground until I had proof that the issue was resolved. Why, because I want to protect my $15K-$20K. In the full-scale world (complete with all its regulations) it can only take one crash before the airworthiness authority grounds a fleet while the investigation is ongoing. This is to protect the flying public. We don't have such an authority in the model world, but that doesn't mean that we shouldn't use a bit of common sense.

[youtube]http://m.youtube.com/watch?v=cr_VO8e9Pi0[/youtube]
Regards,

Jim

ravill

My Feedback: (11)

The problem here Jim is, clearly, you are being reasonable. Really, there is no room for that kind of thinking around here. (This is called sarcasm)

RCFlyerDan

My Feedback: (54)

I want to know what Dumb***** has been ignorate enough to purchase a number of production or kit of the new G-V that they are putting on the market!! You guys' just aren't learning, and will buy FEJ's next latest and greatest jet.

tamjets

My Feedback: (2)

Kris,
They got some right idea. But was wrong how it final install.
My 1/8 scale F-16 rudder had internal linkage system done that way. Very solid system. It will work for F-14. The servo arm need to had sliding pocket closet to the center of the servo at neutral positon. That give max holding power and almost zero slop play.

Look through page 16-23 how I had my rudder done. This is good mechanical set up for elevator too. Just need done with metal servo arm for bigger model.

mikedenilin

My Feedback: (67)

Hi Dantley

It's the FB MIG21. We sent "Notice to Airmen" to all MiG21 owners to ground the planes until we send free stabs replacements. Some of the stab's anti-rotation pins might come loose over time. We noticed that during our routine QC and decided to issue a NOTAM to ground all MiG21s, F5, and F18 until new stabs were made, reinforced, and replaced. No MiG21 was lost in the meanwhile. It's a great flying machine, my personal favorite.

We have a serial number on each aircraft that we sell. We compile a database of all jets, including # of flights (reported by aircraft owners), so we can periodically send new update, safety or service notice to aircraft owners through our automated ERP system. So far it's working good. We caught several quality issues that can cause fly safety concerns and correct them before problem escalate.

I know this is off the topic here, but I hope that other factories can do the same to ensure the safety of our Jet community.

Mike

tamjets

My Feedback: (2)

I do see modelers from time to time make same mistake had linkage set up so poorly lead to flutters problem.
Not just blaming on manufactures.
We are the modelers and should take some understanding lesson how proper install too.
Nothing is bullet proof. But try to do our best.
Pointing fingers is not always the best solution.

FenderBean

I am not trying to start a fight here, but I have said this plenty of times. I personally only like scale jets, and I dont like any of those jets. If BVM had a 1/7 scale F-15, 1/6-1/5 scale F-16 any size scale F-14 and a large scale f-18 I would have tried to buy from bvm, so until someone here in the US starts producing something other than these listed we are stuck buying from overseas companies to get the jets we like.

And as for grounding the fleet, if you do this every time something fails, not a single jet out there will be allowed to fly. Pilot error is still the number 1 cause of crashes

RCFlyerDan

My Feedback: (54)

Wow! THere is still a lot of ignoraces here on the purchase of the product! Guys!!Keep on buying the FEJ product, so that you can keep this forum going ON and ON and ON! You are truly becoming the ignorant consumer to continue to by a pretty "Army overhaul", and think that it will hold up to a true test of Aerodynamics. How often does CARF or BVM make the headlines of RCU on more then 1-4 forums, especially of coming apart in the air?

QUIT BUYING THE PRODUCT AND PRETTY PICTURE IN THE WINDOW!!

TRULY TIRED OF YOU, AS THE CONSUMER, MAKING THE WRONG MISTAKE TO BUY THE "PRETTY PUPPY IN THE WINDOW"!!!!

gunradd

My Feedback: (9)

Tam your system is all good and solid. You dont have the twisting force on the servo case. You pin slides on the servo horn itself. The flyeagle system is the opposite.

The flyeagle system has that pin installed on the servo. The sliding slot is on the elevator. This puts a twisting force on the servo top. Also servo is installed a little ways from the elevator making the pin even longer to reach inside.