LGM Graphix

My Feedback: (22)

One other thought, were either of the formers in the fuse that the wing spars bolt to broken free in the fuse? The builder has to install both of those, and I'm wondering, if one or the other broke loose, it could I suppose cause the spars to shear at the same time. I'm not trying to point fingers at whoever built it, I'm just trying to make sure I can alleviate whatever the cause MIGHT have been so I don't have the same problem with my SB.

Adil Nasim

My Feedback: (61)

Hi Jeremy,

I can't be sure at this point if the spars were nicked while filing and I do not remember that being the case especially with all four of them.

As far as the bulkheads, they were not loose and I had to rip them off with some FG still attached so I can hang on to them. Every piece of the airframe was carfully gone over and I can tell you that not a single glue joint was bad. Even the wing skin pieces I looked had some part of the ribs still attached with the glue being nice and even.

Its very strange. I have never seen anything like this.

Adil

LGM Graphix

My Feedback: (22)

Adil, in all reality, it would only take the rear spars to be nicked, those are the ones I would think more likely to break first with a nick. Those could have broken at different times seconds before the wing came off, then the rotation and flutter of the wings could have sheared the main spars. Wouldn't have to be all 4 spars nicked. It is really tough to file around the rear spars on that wing, the seam is very sloppy and there is all sorts of aeropoxy built up around the rear spar. I'm sorry you lost the jet, I'm really excited about flying mine, but stories like this always kind of put a little bit more fear into a guy :P

JohnVH

My Feedback: (38)

One other thing guys, use 4-40 hardware, a couple guys I know with SB's were racing them around FAST, and could hear them buzz in the air[X(], after going to 4-40 rods, it seems to have cured it.

Gordon Mc

My Feedback: (11)

I wouldn't get too paranoid about it if I were you... although we don't know the root cause of Adil's crash yet, I can definitely agree with his sentiment about how many other Super Balsa Bandits are flown really hard without them experiencing this problem. Mine has been abused enormously, since several of my friends seem to think it is their sworn duty to see how well I build (high G maneuvers, vicious snaps, etc., etc); I also know of aircraft that have been flown significantly over 250 mph with pull-ups that are definitely not gentle, etc. - whatever the root cause may be in this case, the aircraft generally takes an enormous amount of punishment.

Maybe Adil is right about the black paint being to blame ... Adil - I'd offer to send you some of the 'girly' paint I used on my SBB, since it's holding together well -- but then you'd have to constantly put up with a lot of your so-called "friends" giving you crap about how "the 1970's called, and they want their colors back", etc !!

Gordon

EASYTIGER

My Feedback: (119)

Black paint DOES attract negative aerion particles.
Did you have a small hole in each rib for aerion venting?

Miguel Santana

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Jon,
I beleave that for use 50 MHZ frecency in USA you'll be require with a license. Futaba and JR offer there modules in this frecuency too, and only 10 channels are avaible.
Down here each one of us is using one channel and only some of them are repeted, but only with the jet guys....is much easier to control this way....and not only that...imagine for a second that a rookie with a .40 trainer plane shot down a jet plane($$)...How is he going to pay?...no way.
Anyway, not sure but think that 50 MHZ is a CB radio frecuency in US.....check that out.

Adil Nasim

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Picture 1

Adil Nasim

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Picture 2

Adil Nasim

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Picture 3

Adil Nasim

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Last one.

Jackjet

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Real Bummer- I feel your pain[img][/img].........................

Jackjet

David Gladwin

Has any more light been shed on these spar failures? I have never seen such clean breaks on a CF spar which has failed in this way, presumably in the wing bending sense.
Have the spars been examined by a composites expert?
Regards,
David Gladwin.

Kevin Greene

My Feedback: (85)

The only thing that I can think of that would cause this type of failure would be if the anti-rotation pins failed, allowing the wings to twist either up or down. Hmmm--Very strange!!!

tschuy

My Feedback: (1)

Black is really a bad color to use on airplanes. Especially if not kept out from direct sunlight for extended periods of time. I don't know the history of this particular model, but it is a well known fact that using dark colors on composite type aircraft is not very wise due to heat build-up which ultimately can cause the the composite to break down. With full scale kit built aircraft the manufactures warn against using darker paints because of this know deficiency. Do some research and you'll be surprised.

jetpilot

My Feedback: (48)

I seriously doubt this black theory has any substance. Adil is flying in New Jersey with a Balsa Super Bandit which has a built up wing, not composite. Somehow Bv's Composite Super bandit with a composite wing has been able to make it this long in "Sunny" Florida.
Scott

SDCrashmaster

Floid?

uncljoe

My Feedback: (8)

Floid?
Paul, it's like USE 'guys ! its an east coast thing should be Floyd Bennent once a Naval air station (7R tail code) Start or finish of Flatbush avenue. If I get a chance I'll take a few shots of the rally, weather prediction..... Partly cloudy with temps in the hi 70's 15 % of showers in late afternoon.........
Semper Fi
joe

David Gladwin

I am very interested in this failure not because I have a Bandit but I do have a BVM F4 which has carbon fiber spars in a composite structure and I have modified an Avonds F15 to incorporate CF spars specially made for me by CST and I know how incredibly strong this stuff is. I cannot conceive of any aerodynamic force, in the lifting, drag, or flutter sense, which could break off all four spars so suddenly and cleanly, there is more to this than meets the eye. How do we know it is an isolated case, has there been a recent change to the spar material spec., what was the damage to the rest of the wing structure, and has the spar material been analysed ?

I presume this incident and the accompanying photos were put on RCU so the topic could be discussed. The structural integrity of a correctly built Bandit with the correct materials is beyond doubt, proven in thousands of flights. So lets discuss this failure until the cause, or a reasonably likely cause is determined. No one has so far mentioned the obvious. And the contribution from the BVM reps has been deafening !

As ever, I am only interested in the technical truth, not least because I was flying a fullsize type , the Vickers Valiant, when it suffered a similar failure of the main spar, shortly after we lost an aircraft and all crew members in circumstances which were not explained until the wing spar problem surfaced.

Regards, David Gladwin.

erbroens

Flutter can happen with any airplane, no matter how strong it is. I believe that most people here watched this video, a reminder of how destructive flutter can be.....

BR, Enrique

http://www.airandspacemagazine.com/A...A6Flutter.html

EASYTIGER

My Feedback: (119)

Adil's Bandit certainly looks like flutter to ME. Definitive, no. But the only logical conclusion I can think of, though I am open to suggestion.
I would suspect that there was something within the way the ailerons were set up.

Jetkopter

My Feedback: (1)

Curtis, the NTSB is looking for you, they have a new position that just came up designed to save them money. They want to find out what happened to an aircraft with out seeing the parts that failed and coming up with a conclusion based on intelligent speculation. It will save them a ton of money by not having to go to the crash sight and doing any sort of investigation first hand on the parts. You intresteded ? I can tell you first hand from being there it was not flutter. #1 you can hear flutter a mile a way, #2 all of the ailerons and flaps where recovered with there respective linkages. #3 The servo gear trains where intact. #4 I watched Adil and another person both peflight the plane and check all the control sufaces for any slop. The spars have been sent to the manufactuer for examination. I know Adil does not want to point a finger at any one random reason for the failure until the manufacter has a chance to look at the parts. Lets wait until we here from Adil before we come to hypothetical conclusions on our own. I know Adil will share will you all of the findings once he has the answers.


Don DeSandre

Woketman

My Feedback: (6)

I have no idea if it was flutter or not, but I would not make the statement "you can hear flutter a mile a way". Yes, we have all heard the loud buzz of flutter at some of the higher frequencies, but I have also seen soem VERY catastrophic flutter at far lower frequencies that emitted no detectable sound. Perhaps it is even possible to have flutter at higher freqs (or smaller amplitudes) that would effectively be silent (maybe even masked by the turbines noise). Flutter can be loud, but it can also be effectively silent.

EASYTIGER

My Feedback: (119)

Thank you. The NTSB has a position open down at Langley for a Flutter Expert, one who is abfoolutely, definitively versed in all aspects of flutter, I have submitted your resume, Don.

EASYTIGER

My Feedback: (119)

Here, let me repeat this message REAL SLOW, so that even helicopter pilots can read and understand it:

Adil's Bandit certainly looks like flutter to ME. Definitive, no. But the only logical conclusion I can think of, though I am open to suggestion.
I would suspect that there was something within the way the ailerons were set up.


Or maybe is was BIRDSTRIKE like you "hypothetically concluded" earlier on in this thread.

I could think of some actual NASTY stuff to whip you down to size, but I ain't going there, not on this thread, it's already enough of a distraction.

Neither you nor I nor any Stealth Pigeon that causes birdstrike impacts that leave no trace really KNOWS what happened to this poor Bandit, but let me repeat a third time, because it seems to have flown over your head the first time, and I suggest you re-read for a fourth time what I said, before you respond:

"Adil's Bandit certainly looks like flutter to ME. Definitive, no. But the only logical conclusion I can think of, though I am open to suggestion."

Other brighter minds than I can tell you that just pulling on the ailerons and determining "there is no slop" does not rule out flutter, does it?

I mean, there are MANY other things that could cause a plane's wing spars to suddenly shear, right?

Low battery. Oh, wait, no.
Inadequate nosewheel size? Oh, not that. Sorry.
Secret testing of a laser sattelite owned by the Ex-Shah's Secret Service, SAVAK? Possibly.
Black paint? Almost undoubtably.
I dunno, Don, have any other ideas? Besides birdstrike?

Anyway, I'll leave it to others, I'm outta here.