Phantom 3 Professional sudden flip and crash (FlightRecord vid p.2, LogData .csv p.3)

[zincsoldier]

I played the csv in Dashware and slowed it down. Video of it below.

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It appears you first brought throttle full down and then the flip occurred.

I am gonna come really honest. I would never brought full throttle down when I just started motors and wanted to go up and straight out like every other flights. My 1 minute hovering was not recorded on Pilot app so I think it might be the point. The real sotuation was that when I applied a bit of forward direction to the stick, I knew it was acting weird and right on the moment it was about to tilt forward to flip, I pulled the throttle stick down hoping to stop the motors immediately so that I wouldn't get extra damage and plus it was only about a meter high. In the video at 0:22 you could see that I let go of right stick, and i stead went full down on the throttle, that was when I realised it is too dangerous to keep the motors spinning if it fell. On the other hand, I found it is also hard to believe when you review the balance and the direction of the flight data, clearly it hasn't been flipped before I went down hard on the throttle but trust me I realised that moment was going to happen. I did have quite a good amount of flights on both P2 and P3 so I hope I got a little bit of experience to know this was going to happen I appreciate you viewing my flight log and give me a better idea on how it was. Please feel free to add any comments

 

[zincsoldier]

Did you end up breaking any props in the crash?

1 prop was bent and another one ended up loosing inside thread hub, Luckily I was flip-crashed on sand.

 

[zincsoldier]

I have heard that vision positioning system may be responsible for flipping over P3 in case that the surface is odd or water. So when flying above water at low attitude you should deactivate vision positioning system.

VPS was off and I hasn't had a chance of flying over water yet

 

[zincsoldier]

My First Manual land was the CSC way! Flipped it now I only use the single stick shut down. The CSC is open to too many problems if the sticks are a bit off on the CSC maneuver. You may have not done this but just in case.

I did not execute CSC during flight but it still flipped and fell

 

[zincsoldier]

Guys, I have double checked the flight data as .csv under flytrex format. I might have a failing battery at 30-cycle. I would make sure of this and post a screenshot to let you guys know!

 

[Dre203]

The only way it could have executed a forward flip is with forward motion and a sudden stoppage of the motors. I have performed that maneuver many times on my flamewheel. But why the stoppage if CSC wasn't executed? With the right stick forward, CSC shouldn't occur in any manner.

 

[Dre203]

Guys, I have double checked the flight data as .csv under flytrex format. I might have a failing battery at 30-cycle. I would make sure of this and post a screenshot to let you guys know!

That would explain why the motors would shutoff instantly.

 

[JKDSensei]

Absolutely amazing the information you can get with the P3. Also amazing is that with ALL that info, there's still a question as to how this happened

Does the Phantom tend to flip if you shut the motors off while in a forward pitch (instead of trying to level itself).? I would have thought it would just drop....not flip.

 

[Steve Moore]

The flight data tells everything, and it all coincides with the rest of the recorded data. There isnt much that can be argued when the story is already told.

 

[zincsoldier]

The only way it could have executed a forward flip is with forward motion and a sudden stoppage of the motors. I have performed that maneuver many times on my flamewheel. But why the stoppage if CSC wasn't executed? With the right stick forward, CSC shouldn't occur in any manner.

That is what I am thinking too. I pushed it forward and then the P3 suddenly lost power (battery voltage drop in flight log) so it flipped. I would post the battery voltage log soon.

 

[zincsoldier]

Absolutely amazing the information you can get with the P3. Also amazing is that with ALL that info, there's still a question as to how this happened

Does the Phantom tend to flip if you shut the motors off while in a forward pitch (instead of trying to level itself).? I would have thought it would just drop....not flip.

If you are hovering and them CSC us executed, it would just drop 100%. However, if you are pushing it forward using right throttle stick and it loses power, it would flip. This is related to battery problem just after 30-cycle mark.

 

[zincsoldier]

The flight data tells everything, and it all coincides with the rest of the recorded data. There isnt much that can be argued when the story is already told.

Sadly flight record and data were buggy as I mentioned before, I hovered for a minute before doing any manouvers. Well everything were summed up to be a coincident. I updated to iOS 8.4 a few days ago, updated Pilot App with new telemetry on the left corner and map on the right corner a few days ago too, and not to mention the dreaded v1.2.6 which has stopped VPS from working. Life is hard sometimes but what do you do

 

[Steve Moore]

Sadly flight record and data were buggy as I mentioned before, I hovered for a minute before doing any manouvers. Well everything were summed up to be a coincident. I updated to iOS 8.4 a few days ago, updated Pilot App with new telemetry on the left corner and map on the right corner a few days ago too, and not to mention the dreaded v1.2.6 which has stopped VPS from working. Life is hard sometimes but what do you do

The problem is that none of you recent activities could lead to a flip. The only way a voltage issue could is if power was cut to the front motors only, or at least a large differential between front and back motors. A voltage drop along would give a constant drop to all 4 motors, leading to a drop in altitude. There is nothing wrong with iOS 8.4, nothing wrong with the newest Pilot App, and very rarely anything wrong with 1.2.6. Your log may be buggy, but it describes exactly what happened.

 

[zincsoldier]

The problem is that none of you recent activities could lead to a flip. The only way a voltage issue could is if power was cut to the front motors only, or at least a large differential between front and back motors. A voltage drop along would give a constant drop to all 4 motors, leading to a drop in altitude. There is nothing wrong with iOS 8.4, nothing wrong with the newest Pilot App, and very rarely anything wrong with 1.2.6. Your log may be buggy, but it describes exactly what happened.

Here it is I finally got my hands on my PC and able to convert to FlyTrex .CSV file with voltage value here. Seems like the battery failed and dropped dramatically to a low voltage of 16.36V and then went back to normal after the flipping crash. I don't know if my prediction is accurate enough but a bad battery might be the case in my opinion. Please feel free to add any comments as that would certainly help me to justify my case. Thank you!

 

[kyba274]

16.36V is not a dramatically low voltage. The nominal (50%) voltage for a 4 cell lipo would be 3.7x4 which is 14.8V.
At 16.36, each cell should still have 4.09V which is still acceptable.
Your log doesn't show a sudden drop either, but an increase from 16.21 to 16.36...

 

[ScottyT]

There is nothing wrong with iOS 8.4, nothing wrong with the newest Pilot App, and very rarely anything wrong with 1.2.6.

Got to disagree on all 3 counts. There are bugs in all 3 of those things.

 

[ScottyT]

So are you any the wiser? People are saying it's all in the logs, but not actually told you what the issue was...

 

[zincsoldier]

16.36V is not a dramatically low voltage. The nominal (50%) voltage for a 4 cell lipo would be 3.7x4 which is 14.8V.
At 16.36, each cell should still have 4.09V which is still acceptable.
Your log doesn't show a sudden drop either, but an increase from 16.21 to 16.36...

Im sorry I was at work and did not really go into details but to went through what I thought to be critical for the battery. In this case, I think the battery is still slowly failing after a number of cycles which resulted in my crash. I also have been getting the intermittent red-colour voltage then it would go back to green or yellow depends on battery percentage, usually at 50%-70% battery in the DJI Pilot app. Overall, I am pretty sure it is the unstable battery at 30-cycle is causing this problem.

 

[zincsoldier]

So are you any the wiser? People are saying it's all in the logs, but not actually told you what the issue was...

I have contacted 24 hr support on DJI website. They seem to insist it was entire my fault according to the flight log as I was pullong down the stick so hard that it flipped during landing LOL. How was I supposed to land it right after starting the motors and went straight out, plus I had 100% battery, it is common sense I was ready to fly it, not to land it in anyway. Then, I implied on not doing business with DJI in the future, I don't know if they give a **** but they told me they would take this matter to technical support and will send me an email for further information. At the end of the day, I am not sure I am wiser on my problem but this definitely is not my fault.

 

[tvckz]

Im sorry I was at work and did not really go into details but to went through what I thought to be critical for the battery. In this case, I think the battery is still slowly failing after a number of cycles which resulted in my crash. I also have been getting the intermittent red-colour voltage then it would go back to green or yellow depends on battery percentage, usually at 50%-70% battery in the DJI Pilot app. Overall, I am pretty sure it is the unstable battery at 30-cycle is causing this problem.

I doubt it is a battery. It is the same Lithium Polymer as you have in your cell phone. Nothing critical will happen after 200 cycles may be you will fly couple min less. It looks like a power cut. You probably did not insert battery till the second click.