Crashed 450Pro on WalMarts roof

[Goldenhour]

It wasn't a good move flying in the back of my local WalMart but it happened.
I had to get the store manager. When he told me it would have to wait until tomorrow I told him it was a battery type that can catch fire after a crash and I was worried about his roof. A half hour later he comes back with the 450 in hand asking me, "how do you turn this thing off"? The motor was still spinning hard. And I had hit throttle hold.
I was checking out a couple batteries that were to be thrown out but I thought I give them one last spin. After about three high speed figure 8's and a couple loops I lost all aileron control and elevator as well, all right stick control. I had pitch because I was able to keep it inverted for a second or two before it tipped into a death dive.
This may sound like a stupid question but are there times where there is so little voltage or amps that some controls work and not others. I had flown at least 10 batteries today without a problem and I had just done a thorough PM on it. I'm not sure what happened but I will never fly near a building that I cant lay a ladder up against again.
Cost of repair $140, to fly again, priceless.

[DominicD]

Did you forget to setup your Fail Safes ?

[jlharv]

Originally Posted by usakicksass

...are there times where there is so little voltage or amps that some controls work and not others...

I don't see how this could be possible. A low battery on the heli could not tell the radio "keep running the left stick, but shut down the right" Since the same servos that control elevator and aileron also control pitch it is not a matter of the receiver shutting partially down on low battery.

My experience with the pro is that a low battery will cause the esc to cut in and out, causing the tail to kick. And low LVC happens before the voltage goes low enough to shut down the receiver.

Maybe you lost connection for a moment (while you were checking the right stick). Then after the connection was restored, you checked the left stick??

[WillJames]

I am betting it was lack of a rebind at zero throttle as well Capi.


Sorry to see the carnage though.

[Goldenhour]

Now that I reflect on this with a good nights sleep.....the tail was also pirouetting uncontrollably as well until it crashed. I finished a figure 8 go up high to do a loop/ roll, decide to just tail slide back , at that point I seem to loose control. About 20 feet above the roof it pitches left, tail starts spinning uncontrollably and into inverted. I seem to have some inverted pitch but the heli just did what it wanted.
I remember just before the flight on my Dx7 the screen moved up about 10 dots so the top was cut off and the bottom was raised up. Never seen this before.
What are the "fail safes" referred to above?
And what is "rebind at zero throttle"?
I had a satellite on my 6200, what if that came off or failed.
I just want to make damn sure I don't do this again.
Thanks

[Bob O]

Rebind the receiver with the flight mode switch in Normal mode and throttle stick down.

Also, as you already pointed out, flying behind Walmart wasn't a good move.

[heli-on]

I've heard that the satellite antennas on spektrum receivers can cause a brown out if the wires fray or short.

Zero throttle fail safe means exactly that. Take your motor pinion off and power the heli up like you're ready to fly it. Then, turn your Tx off. If the motor spins, you're not setup for zero throttle fail safe. Personally, I don't think you should even be flying the thing until you understand this concept.

[Ah Clem]

"I've heard that the satellite antennas on Spektrum receivers can cause a brown out if the wires fray or short."

A missing or damaged antenna could cause a signal loss, but never a "brown out". Brown out is a reduction in voltage to below the 3.7 volt threshold where the receiver will stop working. Signal loss is different. It would be a failure as a result of an RF problem.

Both can result in a completely ruined day...

Fail Safe helps when signal loss occurs.

[heli-on]

My bad, I always thought they were one in the same, but what you're saying makes sense.

Seems like there should be some kind of protection built-in on the spektrum stuff to prevent it from happening. It's also my understanding that the Rx's with satellite antennaes won't work if the satellite antenna is not connected.

I had a single antenna break off of a 6100 before and that caused some weird behavior (delays in input), but didn't result in a crash.

[jlharv]

I know the Spektrum's will not initialize if the satellite is not connected or broken. But I am not sure what happens if the connection is broken mid flight. I do not think it goes to fail safe though. My son's 450 with a satellite has an intermittent connection. He wiggles it until it initializes and then it never gives an issue in flight. Since a lot of people fly 450 size with a 6100 (no satellite) he does not worry about it.

[Sky1trek]

Originally Posted by heli-on

...
I had a single antenna break off of a 6100 before and that caused some weird behavior (delays in input), but didn't result in a crash.

Now that's interesting, I once had delayed inputs and never knew that could be one of the possible causes. I actually witnessed it on the ground as well. Although it's never happened again.

Anyone know of anything else that could cause delayed inputs?

[jlharv]

too much beer..


It was just a joke. No drinking and flying!

[Danal Estes]

Originally Posted by jlharv

I don't see how this could be possible. A low battery on the heli could not tell the radio "keep running the left stick, but shut down the right"

Agreed.... but... at very low voltages, each physical servo will stick or un-stick slightly differently.

[nwmtech]

Originally Posted by usakicksass

I remember just before the flight on my Dx7 the screen moved up about 10 dots so the top was cut off and the bottom was raised up. Never seen this before.

So let me get this right.... you were flying directly behind a massively populated location with packs that you KNEW were shot and you're TX wasn't functioning properly before you flew?

[Ah Clem]

"I know the Spektrum's will not initialize if the satellite is not connected or broken. But I am not sure what happens if the connection is broken mid flight. I do not think it goes to fail safe though."

I have one experience with this.

My Atom, is equipped with a JR921 receiver. One day I rolled it inverted and heard a fairly loud click.

I rolled it back up right, brought it in and landed it.

The click was the satellite receiver hitting the blades as it was ejected from the helicopter.

[BuckAye]

Originally Posted by jlharv

too much beer..


It was just a joke. No drinking and flying!

ROFL - Agreed no drinking and flying...

But that was funny right there... I don't care who you are...

[f22warzone]

could it have been hit by a high power antenna that was on top of the walmart? maybe one for communications or something? would kinda explain why you had 1/2 contorl

[DrunkRabbit]

Originally Posted by nwmtech

So let me get this right.... you were flying directly behind a massively populated location with packs that you KNEW were shot and you're TX wasn't functioning properly before you flew?

I'm with nvmtech. I can't conceive a safe, responsible flying situation where losing a heli on the roof of a big box-store is a possibility.

I'm glad you got your wreckage back and nothing more serious happened, but I would recommend that you find a better place to fly.

[UBHSTRY]

Originally Posted by DrunkRabbit

I'm with nvmtech. I can't conceive a safe, responsible flying situation where losing a heli on the roof of a big box-store is a possibility.

I'm glad you got your wreckage back and nothing more serious happened, but I would recommend that you find a better place to fly.

I can....Our walmart is vacant in the back, huge flying area. Granted, shouldnt fly over the building, but him flying behind the wallyworld my be perfectly fine. It may not be one that has 10000000 population that even the back side is busy. I have never seen anyone behind our wallyworld. Never thought of flying there either, till now.....I have flown in parking lots at night though, boondocking it.

[terrabit]

Originally Posted by usakicksass

This may sound like a stupid question but are there times where there is so little voltage or amps that some controls work and not others.

Yes! I've have created that scenario on the bench. It resulted in partial control.