Disastrous Beginning

[Marksw]

After quite a long drawn out build of my ARTF plane I took it for its maiden flight yesterday. Bearing in mind I had never flown either so I had recruited some expert help to fly the plane for me. At the field I received some kind compliments on how well my Thunder Tiger Trainer OBL had been put together and choice of components which included: Futaba 2.4Ghz controller and Receiver Thunder Tiger Ripper 36 motor FlightPower Evo 25 11.1v 2700 Li-Po Following lots of checks, particularly build quality/stability checks my friend and extremely experienced flyer launched my plane. To see my hard work fly was just amazing especially considering it was quite windy. He spent a few minutes trimming the controller until he was happy where he pronounced the plane to be quite a delight to fly as well as being easy to fly. Stood extremely close he handed me the controller where I flew a few rectangles before handing it back for its landing. It landed perfectly and I was elated!! Following a battery swap and a discussion he took the plane to the air again, but this time whilst taking the third turn of the rectangle the plane turned quite quickly towards to earth and down it came. It was at quite a hight at this stage so the nose buried itself when it ploughed into the earth, then the Li-Po went up with a quick flame and lots of smoke, even though I had built up some foam on the firewall protruding screws. An airbag wouldn't have protected the Li-Po it hit the ground so hard! Once we got to the plane the Li-Po fire had gone out, quickly, which had not caused much damage, but the plane was destroyed. My friend and others at the field were quite amazed at what had happened. How could a 2.4Ghz controlled plane be 'shot' out of the sky because that is how they described the behaviour, even though we know that this should be almost impossible. No one at the field could give me any answers other condolences. Can anyone here suggest what may have caused this accident? I didn’t use separate Ni-Cads for the receiver which pulled its power from the Li-Po via the ESC which was a Ulso DL 60A+ 2-3 Lixxx. Could the ESC have caused a power 'glitch' to the receiver which caused it to loose the controller? Should I look at sending the controller and receiver back to Futaba, even if it is just to request they give it a clean bill of health? I would love some ideas even if they are guesses as to what might have gone wrong, even if it is to give me a little confidence in my second build. I wont be put off by this and went hunting for another T T Trainer OBL which I have found and ordered but I desperately don’t want the same thing to happen again. (My wife and bank balance wont allow it!) so if there are any ideas please let me know. Thanks Mark

[Aslan]

Sounds like a control surface linkage might have come loose Mark.Did you use a small piece of fuel tubing on the clevises?This helps prevent them from opening.Did your friend say he had no control response.Normaly when in trouble and power is reduced to idle,or motor is brake off,a trainer would be stable and slow enough,because of the high wing and the height that it was at,to gain some sort of control with working control surfaces.What servos were you using?Anyway get cracking soon and good luck.Happens all the time.

[Tim Mackey]

Yes as Aslan says.....happens all the time in this hobby I am afraid. best advice given to me when learning many years ago was

" If crashing your pride and joy is gonna really upset you - take up golf! "

harsh words....but very true. Now what happened ? Well lets see, how about one of these......

1) Your friend cocked it up ( VERY popular reason )

2) The battery connection came loose

3) The battery wasnt properly charged

4) Another electrical connection came loose

5) A clevis came off

6) A control surface came loose /fluttered / broke

7) A horn came loose /broke

8) A servo arm came loose /broke

9) A servo jammed

10) A servo died

11) A pushrod came loose/ broke.

12) One of thousands of tiny electrical components had a bad moment

Shall I continue ?? I think by now you see what I am getting at. This hobby by its very technically demanding nature will ALWAYS carry inherent risks, and pretty much every aeroplane will eventually end up in the great hangar in the sky. Every time we launch a plane, all we ever doing is prolonging the inevitable, and hopefully enjoying it fly correctly that particular time. We should do EVERYTHING we can to avoid such incidents, but we can NEVER eliminate them. It sounds like you did a good job of selection and building etc, and did all the first flight stuff correctly. You are unfortunate and I genuinely feel sorry at your loss, but as my Instructor ALSO said to me after my first "mishap"...

"Its only a piece of wood".  More very wise words............

PS today one should substitute the following for the word "wood"

Elapor, EPP, EPS, PPS, Blue foam, Correx, CSR etc etc.....

Good luck, and get back on that horse !!

[Myron Beaumont]

Stick to proper engines !!!

Giess who ?

[Marksw]

I would stick to 'proper' engines if life were so simple and you could guarantee that this couldnt happen to an IC. But funnily enough I witnessed an IC plane meet its maker at the weekend too. Not sure whos hands it was in though when it decided to commit Harry Carry!! However I am going to clutch at a straw and replace the ESC with a different one and run the servos from Ni-Cads next time. Mark

[Tim Mackey]

Do you mean "Hara Kiri" as in Japanese ritual suicide?

And by changing two things at once, you will never know IF either of them actually was the problem.

I have 8 electric flying ready planes at the moment, and NONE of them is using a seperate Nickel based power pack for the receiver /servos. Unless the servos arer stalling or very heavily loaded, the BEC of most ESCs  should cope fine. Having said that,  I have never heard of the ESC you mentioned - it may be load of poo.

I do think you should do a very thorough check of the crashed model before blaming the ESC BEC. 

[Aslan]

Still think you need to ask your friend if it was responding to his inputs on the way down Mark.Do what Timbo says and give it a thorough check.

[Marksw]

The components (scorched and muddy) are laid out in front of me at the moment being inspected which I'll come back to. Moments before it fell out of the sky the plane was being flown in large rectangles over the field. It all went wrong during one of the turns. It was a turn it had performed before but as it should have started to pull out of the turn it turned towards earth. It was at quite a hight when it turned earthwards and it fell at a hell of a speed but during the fall the plane was not responding to any commands. Nothing at all. When we got to the plane there was still enough power left in the damaged Li-Po to power the receiver as the green LED was still illuminated and was connected/communicating to the transmitter. I should also point out that as it fell the display was still showing on the transmitter so it wasn’t as though the power had failed there. Before I install any of the electronics in my new plane (when it arrives) I am going to see if I can build a test rig from the crashed components to see if any anomalies can be replicated. My big frustration is not knowing the cause so I don’t know how to even attempt to avoid it happening again. PS: 1. I hadn’t used fuel tubing on the clevises but that was picked up at the field when it was checked and was therefore rectified. 2. I am glad you knew what i meant by my Harry Carry (Hara Kiri) thanks for the correction. My spelling is not as good as what it should be!

[Richard Wicker]

Mark.

Hi, glad to hear this accident hasn't put you off mate.

As I don't fly electric and don't pretend to understand your power set up, I can't help on that score. However, it does seem, since you say your instructor had no control at all, that a flat battery could be the cause.

If the battery dies in an IC powered model, you're left with whatever control throws were being inputted at that time. I assume that the same would hold true in a 'leccy model??

[Marksw]

Richard I am led to believe that if the Li-Po was to die, displayed by no more engine power there should still be enough power to power the receiver and servos. So I am led to believe as it should be a design feature. However the crash had followed a refuel (brand new fully charged Li-Po) to which the plane had flown for less than a minute on. Every suggested angle seems to leave me stumped! But thanks for the input. Mark

[Aslan]

Jeez Mark,weird one alright.Tried to google your esc and have no results.Could you check that name again just for pig iron.

[the unmagnificent man]

Hi Mark, sorry to hear about the crash. I am also glad it didnt put you off. Can you recall if the prop was under power as it dived? I ask because if you had no control of the surfaces but the prop was under power then this points to one thing, the receiver. Why? because if the battery had failed then it would not power the prop but SHOULD power the surfaces. Also if there was enough power to power the prop then the same power would control any servo that was plugged in correctly. If the battery was good but you were unable to reduce throttle then this also points to the receiver or the ESC however if it was the ESC then you should still have had some control of the servos controling the surfaces. The only other thing I can think of is that the wind caught your plane at an altitude that quickly spun the plane into the ground quicker than you could react due to nerves. Oh sorry by you I mean your mate. Good luck. Al

[Tim Mackey]

Well actually there are a couple of things here.....

Firstly, an inexpeienced flyer may not easily distinguish if the prop was spinning under power, or merely windmilling as the plane was diving quite fast as I understand it.

Secondly, Just because there may have been enough power to turn the motor /prop does NOT mean that this would also "control any servo plugged in correctly" as the ESC BEC unit may have failed, but it could still supply power to the motor.

As I said earlier, these sorts of incidents can be caused by an absolute multitude of things, and in my 25 yrs+ experience, although most "crashes" are caused by Pilot error, many many things can go wrong with any of the associated equipment.

It is actually quite unusual for a receiver to "fail completely" through an internal fault as such, MUCH more likely to be a poor connection / loose plug / etc.

Another few things to add my previous list....... transmitter not transmitting through aerial poor connection /dirty /not extended fully / bad orientation to model, ETC ETC.

PS when you say it "fell at a hell of a speed" this kinda suggests that it was still under power at the time, AND you say the receiver seemed to respond to the transmitter at the crash site...which all sort of suggests mechanical /linkage/ pilot failure

PPS Your first description of the crash said that as the plane was going so fast, it buried itself up to its nose in the ground, and the Lipo burst into flames, but then you said that the receiver was still working when you got to it, and responded to the tr ??

[Marksw]

Maybe I got a little carried away with the 'burst in flames'! The Li-Po went bang with quite a bang which was followed with a plume of smoke and when I got to the 'crash site' there was quite a deal of scorched wood around the nose cone!! However even after all this the receiver was still showing a green light and when I got back to the pits another flyer connected a voltage meter to the Li-Po which showed 7v. The ESC will hopefully be shown below:

[Andy Green]

Hi Mark

Sorry to hear of the loss of your first model, not much help now but you will get use to it.

 Andy

[Tim Mackey]

Pretty hard to tell just by this picture alone, but it doesnt actually look as if the ESC itself fried, - I reckon maybe the heat of the LiPo fire caused the outward damage to the heatshrink cover.

Have to say again though....... have NEVER seen or heard of 'em

[Mark Lubbock]

I suspect the clue to your problem is that it was a windy day-please let me explain.

I wouldn't mind betting it was on the downwind turn when it happened-even to an experienced modeller, the model would appear very quick on the downwind leg & there is always a tendency to slow the model with elevator to what appears 'normal' speed, but actually slowing the airspeed to a dangerously low level. The downwind turn, aileron & elevator slow the model still further & the model flicks into a spin. This appears very fast & the model heads down with no apparent control with the inevitable result.

This happened to me with an IC engined Spitfire that had lost it's silencer so I tried to land it quickly, slowing it down excessively to lose height quickly-the now tail heavy aircraft bit severely on the downwind turn & rekitted itself in spectacular fashion! It happened very quickly & the aircraft appeared to go in very fast, but with no control at all.

This is just a suggestion, but radio faliure nowadays is very rare especially considering it was new equipment & still working after the crash, even after the fire!

I'm glad you are not put off, Timbo is right that we have to accept the occasional faliure (thankfully much less than in yesteryear!) in this hobby. Hope you have better luck next time!!

[Tim Mackey]

I think this one could run and run and frankly a lot of us could spend a lot of time "guessing" what caused the incident. It is always frustrating and not a little sad when we lose a model, especially when the cause is unknown.

I can sort of accept things better when I KNOW it was my dumbthumbs, or overly enthusiastic attempt at an even lower inverted pass, but when they "just go in" and you are left staring at the tr as if it was it's fault ....thats tough.

I think you will have to just accept things Mark - you will probably never know, especially as it was not even you who had control at the time.

I would just reiterate in closing, that I dont think you should change 2 things simultaneously ( thats even assuming that you use ANY of the powertrain components in the next model ) as this makes it impossible to eliminate any one item.

IMHO you should probably throw away the rcvr anyway, as a very hard impact ( which you descibed it as ) will quite possibly have caused internal damage and probable intermittent performance - I always, at the very least, changed the crystal after ANY such crash in 35 MHz stuff. As you were using a 2.4Ghz rcvr, this is not an option, and I would be very wary about using it in another model now. As for the ESC....well it too has been through the wars, is an unknown quantity of dubious pedigree, and again at the very least, the BEC circuitry could now be suspect, and that ,in many ways , is the most important part of the whole thing!

[Myron Beaumont]

Cor ! I'm even more sceptical about these high capacity batteries & I expect I'm not the only one .  Thanks for your explanation -you seem to have found a way to be in control of this new silent flight non messy aspect of the hobby .With your copy of a proper car

I would have thought you would have been like me (old fashioned & appreciate quality engineering)  ie  fuel ,noise ( music) & by the way I liked the sound track to your video ---Dark side of the moon       Up  Up Up & down down  .Played it many many times in various bands   aye them were t'ut days  Going off thread again    I know    But things ain't what they used to be  are they my friend

Grumpy  

[Tim Mackey]

You're right there Myron, things aint what they used to be because if it was ever called up up down down, then they changed it to "Us and them" . From as you correctly say, DSOTM undisputedly the greatest album of all time. In fact all 3 of my UTube videos feature PF, who also happen to be, coincidentally, the greatest band of all time.

Copy of a proper car ! Cheeky blighter.....tis a real car in its own right, and how dare you suggest it is a copy of a M****n, they themselves had to finally admit during a threatened legal action, that not 1 single panel on the car was actually the same shape as M****n.

Besides.....didnt they used to say "Imitation is the sincerest form of flattery", anyhow, I think my GCS Hawke is far prettier than a M****n and costs around a third of the price, AND is available without waiting 3 years LOL.

I certainly appreciate quality engineering, thats why I built my own car, instead of letting some spotty yoof in Malvern do it for me

PS I actually visited that factory on more than one occasion in the distant past, - had business reasons to be just a block or two away from them, and always thought what a nice old fashioned principled works it was, quaint, but had a heart and soul.

[Richard Wicker]

Timbo sir!

Must agree, Floyd, greatest band of all time. D.S.O.T.M. Hmmmmmm  V.V. Good, but Wish You Were Here gives it a good run for it's money.

Also try Greatful Dead album "Terrapin Station"

As for the car....................... "She who must be obeyed" says she still preferes her MX5.

OK, back to the thread. Pilot Error?? What's that??    NEVER NEVER NEVER, Can't have been sir! Maybe it was a patch of extra strong gravity..............Or, the ground being too high at that point.  .

[Tim Mackey]

Yes WYWH has some excellent tracks - especially wywh, shine on part 1-5, and have a cigar...but when I put my SACD version of DSOTM on my Disk player, crank up the loud button, and lie back with a beer.......Wow EVERY track is just phenomenal

MX5 well..... yes - its a girl's car

Mrs Timbo cant even reach the pedals on hawkey, and if she could, she wouldnt have the strength to depress the clutch...

As for steering when parking, muscles is wots needed pal............ muscles

As for pilot error, well I reckon the ground magnet is a big cause of many crashes

[Marksw]

Ok ok you lot, enough of the car and floyd business, even wifey's looking over my shoulder admiring the car! She'll have me selling the next plane before I even get it in the air so we can buy another blessed car!! To all.............. I have appreciated everyones input and I have learnt quite a bit. Downwind leg during extreemly windy conditions causing it to spiral out of control is the cause I like and not pilot error, so this will be the cause I shall stick to!! (Hmmm wonder if that in itself was pilot error!) Anyway, onwards and upwards and I'll attempt to remember the lessons learnt. Thank you.

[Tim Mackey]

Ah..... so pilot error then

[Richard Wicker]

Ahh, we can all relax now. We have the this problem solved. ............... "Well, you see, I was flying downwind in very strong wind.......... Gale force it was, possibly near hurricane, but I was doing well. Then, just as it started to turn, a tornado touched ground and increased the earths magnetic field...........So it wasn't my fault, all beyond my control, freak weather did it!

Glad we've got that settled.    .