another wing flutter problem f90(crash pics)
 

well this is how it went.... i built this plane by the book and I've built a lot of planes and have been flying for 5 years. The plane went together very well and i was excited about it's maiden flight. got it to the field and had someone double check everything then I put it in the air, trimmed it out and on my second pass at half throttle the wing shook like crazy and the ailoron came off. I have the entire ten second maiden voyage and the proceeding death spiral crash on video. Has anybody done anything about this problem?? Please tell me I didn't just throw away two bills and five stripped servos!? Amazingly, the motor survived the crash. I intend to call Horizon on Monday and have a "come to jesus" discussion regaurding their defective design. Clearly, this isn't right! I am an experienced pilot and builder, and I am far from being a novice...I have flown my funtana 40 3 times as fast and never had a problem. This is driving me crazy. It wouldn't bother me nearly as much if the crash was due to an error on my part - this I could accept. The damn thing even pulled the wood from the trailing edge with the ailoron on the hinges. Sorry to *****, but I really need to vent after such a horrible day.


jeremy

RE: another wing flutter problem f90
 

sorry about your loss, horizon should send you a new plane ASAP and servos as well

RE: another wing flutter problem f90
 

Sorry for your loss. Where is the vid posted?

Ed M.

RE: another wing flutter problem f90
 

i have to format the video and post it. there is a lot of foul language in it after it happened so i might leave the sound off. i will try to leave some sound on it so ya'll can hear how low the engine rpm was when it happened. ill post it when i can

jeremy

RE: another wing flutter problem f90
 

What servos, maybe your servos didn;t have what it takes? No to sound rude or anything.

RE: another wing flutter problem f90
 

futaba 9202 at 6.0volts there around 100oz. they where not metal gear servos but the manual does not state that they are needed

RE: another wing flutter problem f90
 

Those would have been more hten enough, I am going to be running nylon gear Futaba 3010's they get 91 oz-in at 6v

RE: another wing flutter problem f90
 

Dont know guys, but I think Iam the luckiest man or maybe the air in Long Island. 1 year old omp yak 54 with a webra 120 with apc 16/6 and hitec 425. Funtana 90 OS 120 fs apc 17/4 and for servo futaba 3003 and no problem.:D

RE: another wing flutter problem f90
 

hmmm, you say the wood came right out? sounds like a construction. id demand a new plane and see if you can get away with new servos.

sorry to hear about this
Ian

RE: another wing flutter problem f90
 

Jeremy, on the call to Horizon, don't demand anything or have a "come to Jesus" discssion with them. From what I have seen they are good folks and want to help. Like most folks tho, when you tend to piss them off they may still do the right thing, but may take their on sweet time in making it happen. Simply tell them what happned and ASK for their help in correcting the situation. If you don't get what you want you can always ask for a supervisor and yell at them. :D

I'm sure you have read the other threads on this plane about how it does not like any speed at all, etc. etc. etc. One question tho, could yours have had cracked ribs at the aileron servo bay to start with like some have had?

Ed M.

RE: another wing flutter problem f90
 

i think it did, becouse the wing that didnt hit the ground had broken the spars in the wing when i picked it up both wings were very soft and flexing badly i will have a calm talk with them, now that ive calmed down a bit and slept on it ill post back after i talked to them

RE: another wing flutter problem f90
 

That is too bad about the plane. :(.

By any chance did you inspect the wings prior to flight to see if they were soft and flexing? The reason I ask is even though the second wing did not impact the ground directly, the sudden deceleration of impact may have still caused the damage to the second wing.

By any chance do you have any pictures of the mechanical linkage setup you had for the ailerons? Something like the below picture? If you look at the picture below, do you see anythng that might be wrong with the control horn setup?
http://www.hamptonroadsrc.com/review..._Yak-54073.JPG

RE: another wing flutter problem f90
 

Pookie I was going to switch use the same servos in mine now I am wandering maybe newer digitals. I have Hitec HS 77 in it now. I think after reading problems with flutter I will seal the bottom ailerons with some clear ultracote. Can you post any pics of your damage? thanks Steve

RE: another wing flutter problem f90
 

The servos used should have been more than enough. Metal gears are not required. Did you seal the hinge line? Can you tell me a bit about how your radio was setup such as aileron throw, servo arm length, control horn length and where your pushrods were connected? I think we might want to make an addendum to the instruction manual reinforcing how important a good setup is, especially on an airplane like this with such large control surfaces.

As for the wood being broken out.. Flutter is an extremely destructive force and no wood structure would likely survive it and certainly not on such a lightweight airplane as this.

RE: another wing flutter problem f90
 

I do. Personally I think your control horns are too short. I think you're giving up mechanical advantage here.

RE: another wing flutter problem f90
 

Just had a failure today. A good friend of mine and pattern flyer, Raiko Potter, built his Funtana 90 and the first flight was today. The plane went up for trimming and everything was fine. On the third flight he was making a turn to the left and the right wing aileron started fluttering violently, I can't believe he saved it but he managed to land. Both servos on ailerons were stripped, these were 9151 digital servos, the right wing had severe structual damage. It had ribs broken and the leading edge also wrinkled. Raiko was able to save the plane by chopping the throttle and bleeding off air speed to stop the flutter. He is running an YS 91 and at the time this happened he was only at about half throttle. He has contacted local HS to see if this is a known problem. I have one other guy at the field that just had the same problem with his Funtana 90. Severe aileron flutter and stripped servos. He was running the standard servos so we thought that was the problem but now we do not believe the servos were his problem. We are a small group and out of two Funtana 90's both have had the same type problem!!!! Raiko is here with me as I am posting this and we would welcome any feedback. Are there any Hanger 9 reps posting on this forum??

RE: another wing flutter problem f90
 

Have been flying my Funtana 90 now for about 3 weeks with no problems. However today as I was wringing it out it started rolling, I had no control over it as it crashed with a long spiral roll into the cotton field. Upon inspection we found that both wing servos were stripped. I had purchased 5 new Hitec 635-HB Hi Torque Servos just for this plane. I felt that the Karbonite Gear Set (four times stronger than nylon they say) would be perfect for this plane. Anyway, I'll try to see if I can replace the gears with metal if available.
I have a Saito-120 up front, full flying wires on the tail (above and below), balanced perfectly with no additional weight added, would fly inverted hands off. All hinge lines were sealed so I dont think that it was flutter, just extreme force to the control surface.
If gear replacement with metal is not possible, what about replacing them all with HS-645MG metal gear Hi Torque Servos (107 oz at 4.8v)?

RE: another wing flutter problem f90
 

Jeremy
Same thing happen with me. When I got on to talk about it everyone blamed me for the plane being defected. It is a defect in the plane. Don't sweat it Horizon will replace it...I am getting something different. This plane will go down in history as the BIG LEMON for sure.... Be careful around here they will blame it all on you and make you out to be some kind of idiot. Their planes probably have done the same thing but they won;t admit it Now....

There is something wrong with the Funtana .90.. no matter what servos, prop or engine you use . it is going to explode.

Call Horizon and tell them what happen. Mine did not flutter. There was a crack and then the right wing exploded! I have close to 20 witnesses that were there and saw it. I guess these guys can call us all liars if they want. But that is the truth and what happen. It is just a matter of time before it happens to theirs... The plane is defected....

RE: another wing flutter problem f90
 

There is not a thing wrong with his control horns! Too short????? ...You have an answer for everything don't you? No way. they are just right Dougie

RE: another wing flutter problem f90
 

I used the same thing but I used JR on the wings....There is nothing wrong with them on this plane using 5 cell...

However watch the wings..there is a defect in them....

RE: another wing flutter problem f90
 

I told you it was only a matter of time...But we know it was all our faults we are such bad ARF builders and use the cheap cheap servos! Who piut 400.00 servos in a 200.00 plane anyway...might as well get a 40% if you are going to spend that kind of money!

RE: another wing flutter problem f90
 

I am useing 645s in mine. they work fine at any speed. i have been testing mine for flutter in high speed dives. none yet. the 645s are good.:D

enjoy the funtana, as it is a good plane. but with all new planes there are some problems. give it time and it will be fixed.

RE: another wing flutter problem f90
 

You just dont give up do you? You obviously dont know what you are talking about if you dont know anything about mechanical advantage or disadvantage, I bet you had the control rod all the way close to the surface to get alot of throw.

Since you are such the genius :eek: Tell us what you think caused the problem wit hyour wing?? And dont just say its defective as thats not a good enough answer. If you can't tell us in a resonable way what you think is wrong with it or what needs fixed why don't you just stop posting?

And BTW $400 in servos wouldn't even cover the tail of a 40% plane.

RE: another wing flutter problem f90
 

Stavtsivs I liked it better when you sad that you were not going to use RCU anymore.

RE: another wing flutter problem f90
 

I have 200.00 worth of servos and the torque is 90 oz on them. Build the plane by the book and you will have many hours of enjoyment.

I have now over 130 flights on my F90, AND NEVER HAD A PROBLEM! AND I FLY THE HELL OUT OF THIS PLANE!

Like I said before build the plane by the book, and don't try to go cheap on the electronics. [>:]

This is a 3D plane......................:D