XAircraft Should I reused an FC that was involved in a violent crash?

[traxx2003]

So yesterday I sadly lost my beloved Align M480 with SuperX on a violent crash. My question is should I use the SuperX on the new build? Should I just discard it? How can I test its integrity/functionality? I will be building a Skyhero 700. I suspect the cause of the crash was GPS antenna came off of the stand while on GPS hold. Propeller cut antenna in flight. Every part was recovered from crash site except the GPS antenna.

 

[AndyPG]

Hi Traxx,
Considering the crash could have been caused by a number of things, I think if we scrapped the entire electronics package every time we crashed, things could get very expensive.
You could have had a glitch with the RC gear so do you scrap the TX and RX?
Maybe an ESC or a motor failed, do we scrap them all?
Maybe the FC was at fault, maybe not.
Maybe the LiPo died or part of you BEC system.
Maybe it was just some one off rogue interference?

I'd get up and running again and perform some tentative tests in a soft area, ie plenty of trees and maybe long grass or best of all, crops.

Andy.

 

[traxx2003]

Andy thank you for your opinion! So far the radio receiver is able to bind with transmitter, the motors are rotating freely, I still need to run a few batteries thru them to see how they perform. The FC however in order to tested I will need a new GPS/compass antenna to the tune of $140, I would hate to buy this just to find out the FC is bad.

 

[AndyPG]

Mmmm... see what you're saying. I was coming in from a "trust" angle, ie; is it safe or sensible which I would say "do tests" rather than assume bad.
I hadn't considered the high relative cost of the new compass.
You could do lots of initial FC testing without a compass using Atti mode.
I suppose I might then be tempted to buy the new compass then do extensive soft area tests. If you then decide a new controller is needed, buy one as the total for the two still won't exceed a full controller pack, although nearly!
Don't suppose you can borrow a compass to do tests?

Were you in GPS mode when the crash happened.
Don't suppose you managed to switch to Atti mode before the crash?

I know when I've crashed in GPS mode, it happens so quick that I couldn't get my thoughts together to switch over.
Usually just panic for the failsafe switch which won't save the day if its a compass issue.

The last bad crash I had was when I calibrated the compass in between two large metal objects (a JCB digger and a huge shipping container) Couldn't get full satellite lock but (stupidly) flew anyway in GPS mode. Lost control after a few seconds and crashed badly from height.
If I'd had the presence of mind to switch to Atti mode, I would have deffinately been back in control.

Just thought I'd share that.

Andy.

 

[traxx2003]

No worries Andy, when the crash took place I was flying in Attitude mode which means that the XAIRCRAFT FC was relying on onboard gyros and barometer sensors to keep control. Throughout the flight I had 13 satellites lock in. However when I realized that something was wrong I did activated the fail safe which like you stated didn't do squad, next I went into GPS mode and still no control. By the time it occurred to me to try manual mode it was too late. Not sure if you are familiar with the XAIRCRAFT FC but one feature it has is that the FC creates and stores flight parameters for every flight. Below is the link to my flight log, make sure you select flight # 76.1.06.07. That was the flight that crashed. Anyway thank you for your responses.


http://log.xaircraft.cn/#2015_06_13_100521.429_76.1.06.07

http://log.xaircraft.cn/report.htm#2015_06_13_100521.429_76.1.06.07

 

[fltundra]

No worries Andy, when the crash took place I was flying in Attitude mode which means that the XAIRCRAFT FC was relying on onboard gyros and barometer sensors to keep control. Throughout the flight I had 13 satellites lock in. However when I realized that something was wrong I did activated the fail safe which like you stated didn't do squad, next I went into GPS mode and still no control. By the time it occurred to me to try manual mode it was too late. Not sure if you are familiar with the XAIRCRAFT FC but one feature it has is that the FC creates and stores flight parameters for every flight. Below is the link to my flight log, make sure you select flight # 76.1.06.07. That was the flight that crashed. Anyway thank you for your responses.


http://log.xaircraft.cn/#2015_06_13_100521.429_76.1.06.07

http://log.xaircraft.cn/report.htm#2015_06_13_100521.429_76.1.06.07

If there was an issue with a motor or esc. Switching to manual or fail-safe wouldn't have made a difference.
Was the FC still secured after the crash? Looks like something might have shifted mid flight.
Hard to tell without actually being there when it happened.

 

[traxx2003]

Yes the FC was secured to the frame. But I wasn't able to find the GPS antenna no where near the crash site. I suspect that maybe the antenna came off and one of the props cutoff the cable. Could that caused to loose control like that?

 

[AndyPG]

From an FC point of view, only if you are in GPS mode. In Atti mode, your FC wouldn't even know the compass had gone..
That's not to say that the compass module didn't trash a prop which would cause the crash.

Andy.

 

[traxx2003]

Yes.... I'm afraid I'll never know for sure what downed my aircraft. Can Futaba 2.4GHZ signal be jammed in order to cause this ?

 

[AndyPG]

If you were flying in a remote location its highly unlikely.
2.4ghz and 1.2ghz fpv video transmitters shouldn't be used with 2.4ghz RC though.
Here in the uk, the 2.4ghz band is jammed full with use by various technologies but complete loss of control is rare even when flying in residential areas.
Futaba gear is particularly good.
Have you got any Futaba failsafe systems that could have intervened?
With a quad, I turn off the RC system failsafe so the FC has no means of confusion if my signal is lost.
Andy.

 

[fltundra]

With a quad, I turn off the RC system failsafe so the FC has no means of confusion if my signal is lost.
Andy.

That is absolutely the wrong way to ever setup a FC that has GPS and RTH. SuperX is very simple, +100 ch 6 only.
Not setting up fail-safe is putting you and others at risk on the ground.

 

[AndyPG]

Thanks fltundra, if no further good comes of this thread, I have learnt something important. I was under the impression that my FC would automatically go to failsafe if my tx signal was lost. I'll work on it tonight to sort.
Although, I must say, before I get too guilty of putting myself and others at risk, there are many thousands of aircraft out there who are not even equipped with failsafe nor RTH, both of which are required to avoid a dangerous occurance. Lets not be too heavy handed with each other. Thanks for the prompt though.

Andy.

 

[AndyPG]

Failsafe set up and checked working on my FRSKY receiver. Thanks again fltundra and you traxx for starting a thread that lead to an important bit of info for me. You've probably saved my quad from total loss as I experiment with longer range sorties.

Andy.

 

[traxx2003]

Guys today I received and email from Mr. Jingchen at XAircraft support and he said that after reviewing my flight log he discovered that at the moment of the crash the GPS position accuracy was not corrected, indicating to the possibility that the GPS antenna was not positioned/installed correctly. Based on his findings and the fact that I flew fine for the first ten minutes the only conclusion I can draw from all of this is that the FPS antenna came off in flight from its stand. The only thing that confuses me however is that before I loss control I've been flying on attitude mode, and according to someone on this forum when in attitude mode the SuperX does not rely on GPS data but rather on its onboard sensors to maintain controlled flight. If Mr. Jingchen assessment is correct then I guess the GPS had to come off in flight.

http://log.xaircraft.cn/#2015_06_13_100521.429_76.1.06.07

 

[fltundra]

Guys today I received and email from Mr. Jingchen at XAircraft support and he said that after reviewing my flight log he discovered that at the moment of the crash the GPS position accuracy was not corrected, indicating to the possibility that the GPS antenna was not positioned/installed correctly. Based on his findings and the fact that I flew fine for the first ten minutes the only conclusion I can draw from all of this is that the FPS antenna came off in flight from its stand. The only thing that confuses me however is that before I loss control I've been flying on attitude mode, and according to someone on this forum when in attitude mode the SuperX does not rely on GPS data but rather on its onboard sensors to maintain controlled flight. If Mr. Jingchen assessment is correct then I guess the GPS had to come off in flight.

http://log.xaircraft.cn/#2015_06_13_100521.429_76.1.06.07

You lost it right here:

 

[traxx2003]

So that's probably when the GPS antenna became loose/separated from rest of quad?

 

[fltundra]

Pretty good chance the GPS wires may have shorted when you lost the puck. Did it cut through the cable or yank the plug out of the IO?
View attachment 25087

 

[fltundra]

So that's probably when the GPS antenna became loose/separated from rest of quad?

Yes

 

[traxx2003]

Just like the picture above, it cut right thru the cables. I never recovered the antenna itself, plug was still attached to the FC.

 

[traxx2003]

I mean pluged to the I/O unit.