ben.p.smith

Had an interesting experience tonight while flying my H9 Funtana 40. I want to preface this by noting that I have been flying for 23 years and have built from scratch, kits or designed well over 60 airplanes. In this time I've owned a total of 2 ARF's... one about 20 years ago and the H9 Funtana. I've had plenty of "dumb thumbs" incidents and a few electronic failures... but never anything remotely close to what happened tonight. While doing a series of fairly violent snaps the entire tail of the airplane sheared off in flight! The only thing(s) holding the tail to the fuse were the control rods for the rudder and elevator. Luckily the plane pancaked into soft mud.. so it will be a fairly simple rebuild... but I have never had a structural failure on any plane I have built from the ground up. Upon examining the tail, it appears that the entire assembly is literally butt glued to the rear of the fuse. Except for the 1/8" balsa fuse sides (that had a lightening hole just aft of the joint) nothing of any substance was actually holding the tail to the rest of the aircraft.... just butt glued balsa blocks and stringers CA'd to the lite ply rear bulkhead! Now I do have to admit that ARF's have come a long way in the 20 years since I had my first one... but this is just an example of poor joining, glue and engineering. Those of you with this model, I would highly recommend beefing up this joint with some epoxy and perhaps a few stringers.

I also pulled back the covering at the wing joint... but haven't had time to really dig into the assembly. There is absolutely no fiberglass reinforcement at the joint... and again the wing halves are simply butt glued together. It would be a wise idea if you are flying this model to run a 2" piece of fiberglass around the wing joint. Just FYI...

FlyerInOKC

My Feedback: (6)

Its an ARF from China, this is the country that builds cheap, but they do have a few bad apples in the barrel Look what some unscupulios suppliers did with lead paint on toddler's toys and Antifreeze ingrediants in toothpaste. I wouldn't be surprised if H9 had no idea this plane was built that way. I imagine they went over the prototype and the first shipment with an eagle's eye on quality but didn't realise how close they needed to watch their suppliers. I have had excellent support from Hanger 9 in the past and consider them to be a very reliable company and I love their products and make purchases of their products regularly. I would recomend you bring it to their attention so they can watch this supplier a little closer.

Jon.

Can you show me a picture of where the tail sheared off? Thanks.

Jon.

mjfrederick

Ever hear the joke about the guy who went to his doctor and said "Doc, it hurts when I raise my arm above my head like this..." The doc says, "Then don't do that." You answered your own question in regards to why your aircraft failed... "after a series of violent snaps." The doc would tell you not to do that...

ben.p.smith

I've attached some pics of the fuse and the tail. As you guys can see, aside from the balsa fuse sides, the tail is simply glued directly to the rear lite ply bulkhead. Had the fuse sides been supported by 1/8" x 1/4" spruce stringers that ran at least 4-5" into the rear of the fuse, this failure would not have happened. The stringers that can be seen in the pics are simply butt glued to the rear bulkhead. Now it is fairly typical practice to butt glue the bottom balsa block and the top balsa fairing blocks to the rear bulkhead, but the cause of the failure here is definitely the lack of stringers running into the fuse... they were just being glued to the bulkhead. In regards to the above comment about "overflying" the airframe. I agree.. to a point. However, had the airframe been properly designed/built, the snaps I was doing would not have been an issue. I have put much lighter built planes of my own design through much worse without problems.

mjfrederick

Now that I see your pics, I see what you're talking about... bad design. Wouldn't have been as bad if that hole hadn't been carved out in the sides right below the stab, but that tail design is destined for failure even just doing moderate aerobatics.

ben.p.smith

That's kinda what I thought... bad design. I did buy this airplane a couple years ago when they were first released. I would hope that this was an early production problem that has since been resolved. I'll probably bring it to H9's attention anyhow. I'm certainly not bashing ARF's by any means, but you just never seem to know what you're gonna get. If this is a problem that still exists with the plane, then I'm sure there have been or will be many, many more destroyed aircraft as a result of this engineering error. It could be easily fixed on existing models, but that will require carving into the fuse... something that shouldn't have to be done on an already built model.

JUGFLIER

I have had a total of 4 funtanas. 3 were the older version and one was the newer. The newer one suffered a massive wing failure and was destroyed inb a crash. The wing at the center section had only quarter inch basswood stringers for a spar. The wood was cut on the end cross grain, well you can see from there, wing folded and a crash.

Nathan King

Wow, that's one of the worst designs I've ever seen. Most companies seek out the lowest bidder for their products, which doesn't typically breed quality.

suitcase

My Feedback: (1)

This plane has had issues since it was released. From bad flight characteristics to wing and fues failures. I have one I bought off of Ebay cheap and wouldn't have paid full price for one from H9 because of the bad talk about it. I had seen them fly by very competent pilots so I know what they're capable of. They will fly great but do have the issues. I'm flying mine with a Saito 82 and don't pust it to far. Still I'll probably sell it soon, while it's still in one piece.lol

ben.p.smith

Well I sent an email into H9 customer support.... I guess we'll see what happens. I doubt I'll hear much if anything at all. I really wish Horizon (and the other manufacturers) would at least make short kits available for the ARF's they produce. Heck... even a set of plans would be fantastic. I really like the appearance of the Funtana.. but I know I could build it a heck of allot better than some Chinese laborer.

Jon.

My wing failed! the leading edge of the wing smashed when I hit a tree

ben.p.smith

Well I wish I had somehting positive to post. I sent two separate inquiries to H9 product support. Never heard anything. Heck... even a simple "send us some pics and we'll look into it" would have been nice. To say I'm disappointed would be an understatement. What really torques me off about this situation is that the plane was destined to crash from the get go due to a horrible design. Though a dumb thumbs crash is never any fun, I can certainly tolerate those much better as they are a direct result of my own actions. Structural failures are another beast all together... especially when the failure is something outside of my controll. I doubt I'll be buying any more ARF's in the future. Too bad so many good airplanes out there are only available pre built.

nitro wing

My Feedback: (1)

Well,its too bad that you got one that was a bit weaker.
Do you know how many thousands of those were sold?many to pilots that flew them extremely hard. And most were fairly happy owners.I dont think there was a huge failure rate on these,unless I missed it over the years.I had one.I abused it severly and put a way bigger motor in it.Every run of ARF's will have an issue with a few models being lemons.Humans build them and humans fly them.There wil be errors.It does not matter what company you deal with. I have had the most expensive and the cheapest fail on me. I have also had the cheapest give great performance and have the pricey ones give me trouble.At this time an ARF is a bit of a gamble be it 40 size or 40%.There is no guarantee.
As factories get established and workers get good training the product will improve as it has over the last 10 years.
I know many builders,and most would have trouble producing what we take for granted now,as we open a box and salivate at our new purchase.Something that would have taken 100 hours and twice the money to build ourselves.Your failure was definately not something normal and documented.Sorry for the loss.Good thing it was only a 100$ plane.
Mine died with a traumatic ground impact.Everything from the cockpit back was completely intact and functional afterwards.

aerowoof

his point is that hangar 9 ignored him and that can leave a bad taste in your mouth for all arf's.

Deerslayer

I have a Funtana X50 with, as depicted in the book, a Saito .72 4-cycle engine (I bought the plane to wrap around this engine which my son gave me).

For what it is worth, although the book of instructions shows there being a complete circle cut out at the stab/fin joint, mine has a 3/4 circle cut out. That is, there is no cut-out in the bottom front sector. Overall, I thought that a giant hole was a pretty weird arrangement to begin with, making no sense from an engineering viewpoint. Now, I wonder if there had been some feedback from tail failures with earlier models that led to the slight difference in the X50? Since the thing was already covered, one could not really tell if a chunk was simply butt-joined back into that segment.

I have built over 50 airplanes during my 30 years of R/C, many of my own design, and I am a professional engineer with some experience with "full-scale" aviation. This is the first ARF I have owned but I have flown and/or closely examined many. I really like the aircraft as it flies. I did learn a couple of important lessons, at least one of which I was simply the last in a very long chain of local pilots to learn. That involved the landing gear. Whoever designs the things somehow thinks that it is important to bolt the gear on with honkin' big STAINLESS STEEL bolts - into a little plywood chunk marginally attached to a marginally adequate laser-cut liteply fueslage. After mine broke out during an engine-failure-on-take-off triggered rough landing (not a crash, and it surprised me that there would be any damage), I did what I should have when I assembled it - change this to a proper, larger area plywood plate and use plastic bolts. I have since examined a few other ARFs and it seems common to use these stainless steel bolts into rather delicate fuselages. Very poor engineering, I think.

nitro wing

My Feedback: (1)

Oh I realize that,but how many e mails to they get from people that may not have a legitimate claim?
What can he say? "I did a series of fairly violent snaps and the tail fell off"
They are going to ask themselves,did he have a larger than recomended engine and how fast was his airspeed,why should they come good for it.
Yes they should reply to him either way.
I'd like to see the email he wrote them

ben.p.smith

Sheesh... I didn't want to turn this thread into any sort of debate. I just wanted to point out that the version of the Funtana I bought had a defect. Any builder/pilot worth their salt would immediately recognize the problem with the way the tail was attached to the rest of the airframe. Unfortunately, the only way to answer this question is usually post-mortem. The sad thing is that this could have been totally avoided with a few small stringers that actually ran into the fuse. The "event" happened at relatively low airspeed with the engine (Irvine .46) at low throttle. Since this aircraft isn't designed to fly at high speed (look at the airfoil) I only tend to use high throttle settings during takeoff or hi-alpha aerobatics. My email to H9 was nearly verbatim to the posts I have written here and was in no way mean, threatening or inappropriate in any manner. Yes, I am sure they get a number of gripes on a regular basis... every business does. I just wanted to hear something back. I don't want a new airframe at all. Really.. I don't. I've got enough aircraft collecting dust that I'm sure I can find something to fly. I will rebuilt the Funtana the way I want. I Just wanted to know if this was a early model defect or something else. Now, with that being said, I'm sure there are plenty of nice ARF's and not so nice ARF's out there. BUT whether it's a $100 or $1000 airframe, it should at least be built structurally sound out of the box. At least when I build or design a plane I know that it was done correctly. As I said before, I have put many, many other aircraft through much, much worse than the snaps I was doing with the Funtana... and they all survived. Who knows, maybe I just got a bad one... perhaps the Chinese factory worker ran out of wood and decided just to glue a couple sticks together to make them longer. I'll never know. What I do know is that my overall impression of the product and service has been soured... even after going through all the right channels.

nitro wing

My Feedback: (1)

Well if you managed to do that with a 46 at low speed then its not right.Not sure why yours did that,poor design or not,this particular fracture is not common at all.so it cant'really be called poor design if the other 10,000 did not lose their tails,even though this butt joint seems very suspicious.

daveopam

My Feedback: (9)

You should pick up the phone and call Horizon. The email route is easy to ignore. Once you have them on the phone you can explain you problem.

david

nitro wing

My Feedback: (1)

and if possible ask them to pull up the email with attached pics..while you got their attention..

gumhead

Or give them a link to this thread...

ben.p.smith

Well I got a nice response from Craig over at H9 service. They want to take a look at the airframe to see what went wrong. I figure I strip my gear out of it tonight and send it their way this week. Though it did take a few weeks, I am very impressed that H9 is following up on this. Would have been nice to get an email within a few days of my original inquiry.. but they are looking into the issue now and that is what counts. I'll let you guys know what they find out. More than anything, I am just curious as to if my particular plane was built to an earlier set of standards or something.

nitro wing

My Feedback: (1)

Maybe it got damaged in assembly and they fixed it hastily,who knows.Its good that H9 wants it sent in..