Totally hacked off.... opinions please (thanks)

[vtrnutter]

So I've been progressing at a fair rate of knots in the past month. Last weekend, I only took my training gear off, this weekend I've managed nose in hovering and my first circuits.

My session down the park yesterday taught me a lot about flying in the wind, so today I decided to go out and do another 4 packs down the park.

I was on my 4th pack, heli had been flying beautifully all the time. Suddenly, I seemed to have no cyclic control, and she was drifting on the wind towards trees, buildings and a road. Gave lots of stick input but nothing.

Had to make a quick decision to hit throttle hold, and of course, due to no cyclic control, had no chance of an auto.

It's fair to say she came down like a meteor, just missing the roof of a building and decked into just about the only piece of concrete in the grass.

My first thoughts were on servo failure.

Gathered the mess of broken parts (including a rather mis-shapen LIPO) and took home.

Plugged in LIPO at home and all servos are working fine.

Given that when I hit Throttle Hold, the motor died instantly, rules out receiver failure for me.

I have just been over the log in the Castle Creations Ice 75 that I have - nothing obvious standing out. You can clearly see in the log where I hit the TH, as the revs drop, and throttle goes to zero. But no other events recorded.

Of course, not much to see in the remains of the head, which is pretty much shattered.

As everything seems to be in working order, my only thought is on whether the swash separated or not in flight.

Any opinions or help that anyone can help would be appreciated.

AS you can imagine, I am totally p***ed off. I don't mind crashing when it is my fault, or if I do something stupid, but in this case there was no control and nothing else I could do.

Part of the hobby I know, but right now that does not help!

[sacko]

I would tak a punt and say that the swash seperated in flight, would make sense...

Did the pitch change at all (did it shoot up or down) when you lost cyclic?

[vtrnutter]

Can't really say. Am a bit inexperienced, and it all happened rather quickly, so did not get the chance to really try too many different things. All I could think of was that my pride and joy was about to become suspended in the top of a tree!

[Gav]

Unlucky nutter


I reckon the heli would of done a bit more than drift it the swash separated. What about servo leads - have any chaffed on the frame? I guess you would see glitching if was something like that. Sounds like some weirdo radio / tx / rx connection fault but as your t.hold worked then I'm not sure. Damn not good. Good luck with the rebuild and range check on the next outing for peace of mind.

[GravityKills]

>> my only thought is on whether the swash separated or not in flight.
I guess it did...
Otherwise, I would have guessed you lost a ball link, it happens occasionally.

[Paulice]

I think if the swash had separated in flight the main blades would have feathered going to 0 degrees, the heli would have come down quite fast.
Going off all the problems with Spectrum DX8's it might be that???

[vtrnutter]

I think if the swash had separated in flight the main blades would have feathered going to 0 degrees, the heli would have come down quite fast.
Going off all the problems with Spectrum DX8's it might be that???

Hi, yes I thought about that - hence I went over the CC Ice75 log with a tooth comb. I would have expected to see a log entry showing loss of radio signal, plus the fact that the throttle kill worked was kind of telling me that the RX was working ok.

[jwatts007]

Was the pack fully charged..........

[vtrnutter]

It was coming to the end of the pack. Running on an external BEC so there would have been plenty of power in the battery to run the electronics, even at the end of the pack (6S)

Steven

[GravityKills]

a broken swashplate sounds quite plausible: Even if the upper part has separated, there is still positive pitch enforced: It can't move past the lower part.
Another possibility is a ball link to a blade. It feels like losing cyclic.

[cjcj1949]

I agree with Paulice. It sounds like a radio problem. If a link had popped it wouldn't have drifted nicely. A tx problem does not have to be a loss of signal. At least not a loss of rf. You still had control on throttle, but you seemed to loose cyclic. It is possible for a tx to lose one or more channels as happened with the pot (potentiometer or volume control that converts stick movement into a resistance change) problem on the Dx6i. If I had a Dx8 (only money stops me getting one) I'd be using it on my msr to make sure it was ok.

The lipo check you did is not foolproof, by the way, as all batteries recover their charge after a rest. I'm not saying it was the fault either.

I've had crashes that (I think) were'nt my fault and that I couldn't find answers to and I'm an Engineer or was. One of our problems is that there are so many ways to crash a heli and the crashes destroy the evidence.

I binned the old heli and started again. Once you get it going again test it on the ground with a few batteries just to make sure that whatever caused the problem died in the crash.

Chris

[alioth]

a broken swashplate sounds quite plausible: Even if the upper part has separated, there is still positive pitch enforced: It can't move past the lower part.

I would imagine that air loads on the blades would keep the two halves of the swash together, and in the case of a failed swash plate, you wouldn't see any problems in flight unless you tried to fly inverted (at which point, the air loads for steady inverted flight would be pulling the two halves away from each other).

[Mutley]

I know its been suggested it was a swashplate issue but surely the throttle would of worked then and i'm assuming it diddnt as it sounds like it was drifting away so there was no pitch control.

only other thing is, if throttle hold was working, and i know its hindsight, might of been able to use this to control height, even a quick stab as it got close to the ground would of saved the damage - pretty sure i read on here somebody managed to land like that using the throttle hold as an on/off

I bet it was battery failure, i had a similar thing, in a 2mt hover it started to drift up and away at an angle of 2pm away from me luckily. I tried a couple of things then hit throttle hold - which worked, without issue but the other servos wouldn't, changed the pack and it was fine.

[vtrnutter]

Thanks for all the replies. I have to admit, being a newb, I did not perform a range test before the flight. Although at the point of failure, the heli was almost directly overhead probably about 25m up, when at various points during the flight it had been 100m or so away at the same altitude with no problems.

Interestingly, I performed a range test today with my DX8 and Blade MSR, and it failed rather spectacularly. Now, admitedly this was in very unfavourable conditions (the heli was inside on a window sill, and I went out through the house so the reduced signal was going through a couple of walls) - but it failed much earlier than I would have expected - especially as the full range test is supposed to be over 30m. Today, this was over less than 10m, with 2 walls in the way.

Needless to say, this will be getting a proper check over once I have the heli rebuilt, and any suspicion of failure will result in TX being sent back. I don't want to jump to conclusions at this point so will wait and see.

Steven

[Swashbuckler]

You can't really expect it to range check through walls. You really need unblocked line of sight for 2.4 (yes I know wireless networking works through walls but it's signal is seriously reduced and is not a life dependant signal!) if there is anything in the way all figures are out the window. Anything with water content will affect it dramatically too. So a wet wall or a bush or a misty day will make a big difference.