Hi.

The event happened in late October 2015. p3p with this firmware on p3 P3X_FW_V01.04.0010.
The reason i write now is because i bought another  gimbal and now the bird is functional again. But before i go out with it  i want to know  why  did it  fall from the sky with no reason. I’m scared to fly it again until i know that my p3 is perfectly functional.

I ask here help from DJI team to look into my logs and tell me if it is safe to fly  my p3.

Ill describe the crash.

Weather conditions:
Clear sky , little wind, about +15 degrees Celsius

P3 : Battery at 70% when I start the flight (I used p3 few weeks after last full charge of the battery)

P3 fall down from 80m i think, my luck was that it fall in to some bush that protected the craft and damaged only gimbal with no visible signs of damage, but no working state.
My impression was that the plane lost  power in the air. (Battery problems?, battery connections problems?, or something else)

Its very important for me to know what happened..
I’m not asking here warranty or free repair, I already repaired the craft. I only ask from competent support team to look and tell me the reason of the crash. If there is a battery connection problem or battery problem I should know to fix it before another flight.

Here is my dat file  acording to the crash flight
https://www.dropbox.com/s/pp0uaauq8f28ptb/FLY058.DAT?dl=0

Sorry for my English.

Thank you

  

If you have your logs, upload them to http://healthydrones.com/

I am definitely not an expert but flying with anything less than a 100% charged battery can cause problems, (I have read about this many times). Some people say 70 - 90% is okay but I won't take a chance and always start with 100%. Also, clink on this link to read more about this. Fly With Less Than 100% Battery

microcyb Posted at 2016-2-19 21:01
If you have your logs, upload them to http://healthydrones.com/

Thank you. Unfortunately i don't have txt from dji go app. I don't see the flight there in the dji go. only older fights... Maybe i didn't syncronise with internet  at that time and the data  have been lost  from the dji app data  from my tablet.

I can point you to my video which shows what happens when a flight is made with a partially charged battery.  Solution is to hover at low altitude for 2 minutes to warm up the battery.
http://forum.dji.com/forum.php?m ... 0&fromuid=47441

Tintin Posted at 2016-2-19 21:15
I am definitely not an expert but flying with anything less than a 100% charged battery can cause pr ...

Thank you for reply. I think  it should be safe to fly with over 70% battery, but i will take your advice  from now on.. Safer is cheaper... i learned this in the hard way.

hummingbird.uav Posted at 2016-2-19 14:19
I can point you to my video which shows what happens when a flight is made with a partially charged  ...

Nice tip you have there.. Thanks!

yul Posted at 2016-2-19 19:20
Thank you for reply. I think  it should be safe to fly with over 70% battery, but i will take your ...

Good luck

hummingbird.uav Posted at 2016-2-19 21:19
I can point you to my video which shows what happens when a flight is made with a partially charged  ...

Thank you .  Useful information...... Although the p3  fall from the sky at over 50% battery... no warning of low battery, no descending start . The question is that  ......Is it posible  that the cold and not fully charged battery to give p3 reset from missing power?

Hi.  I have found a .dat log  decryption method here.  It may be useful for others too.
https://www.mapsmadeeasy.com/log_viewer

U can download the dat logs from p3  in this way:
http://support.dronesmadeeasy.com/hc/en-us/articles/206171443

I succeded to decrypt the log file. I can see that the p3 stopped all log recording in the middle of the flight right after fast forward ascend command (power request from the motors high). There are 2 flights in that day , first between 12.02.01 and 12.02.59, and second between 12.08.47 and end of log..maybe 2 min.
Conclusion is that p3 has lost power in the air..... I want to see why and  im looking for the log data about battery.
The site  where i decrypted the log file give limited info ... No battery info....
DJI support.. Please give me a hand here. I think its important data for DJI   to know  more about so called cold environment crashes.(i think this could be the case or not)

I would like to share a similar flight situation from a few weeks ago, although my P3A did not crash.
I flew with a 80% charged battery that was last used 12 days ago. Thought that was okay... My mistake!
Two minutes after flight initiated, I noticed cell voltage (on battery info screen) dropping to 3.6V.
I quickly brought the P3A back. It landed with average cell voltage 3.3V.
The battery was still showing 55% on main page!
Did the battery not warm up and gave bad cell voltage reading?
No matter, after this I always initiated flight with freshly charged batteries.

hummingbird.uav Posted at 2016-2-20 06:19
I can point you to my video which shows what happens when a flight is made with a partially charged  ...

He was flying in temperatures of 15 Celcius, that's not cold. It equates to 57 F.

I think the issue is that the battery was at 70% at the start of the flight and it was several weeks since he last fully charged the battery. And, yul says later, he had just given the aircraft a 'fast forward ascend command'. This is the critical point, as it means he asked for maximum power from the aircraft, and that requires maximum power demand from the battery.

I have written before that I believe this high power demand on a partially discharged battery can cause a substantial dip in the battery voltage, enough to cause the control circuitry in the aircraft to reset. It is that reset and subsequent restart that stops the motors, causing the fall.

yul Posted at 2016-2-19 14:20
Thank you for reply. I think  it should be safe to fly with over 70% battery, but i will take your ...

your are not wrong in thinking that.

it seems that the percentage that is shown at start may be HIGHER than they can provide for more than a few moments.

sitting  the app may show 70% but after you lift off and a load is placed on the battery the voltage available to use drops rapidly and shuts it down sometimes.

When the battery sits and discharges somewhat it has been noted that the only way to KNOW for sure the REAL battery level is to charge it 100% prior to use.

one of the times "reality" and "should" don't match.

good luck and have fun flying

yul Posted at 2016-2-19 16:39
I succeded to decrypt the log file. I can see that the p3 stopped all log recording in the middle o ...

Your full power lift on a battery that has begun self discharge is likely the cause of your power loss rather than a problem inside the quad(except fw & battery)

do some searching in forums the last 2 months on FW 1.5 and 1.6 updates to get the background of issue.
good luck!

P3 firmware was 1.4  when this happened,   And  all the summer i have used the p3 over the sea from 100% to 30% of the battery with no problem 15+ full flights. The change on this flight was  lower temp and not fully charged battery.  There is another difference .....  starting altitude is 722m if that can be important....(high altitude flight)
Yes starting with hummingbird.uav  post  i started to read few post with battery issue that give low battery warning.

What should be the conclusion in this case.. Do i fly safe if i charge 100% ?

Not only was it at 70%, but if it hadn't been used in over 2 weeks, it would have entered hibernation mode in order to discharge.

yul Posted at 2016-2-20 09:37
P3 firmware was 1.4  when this happened,   And  all the summer i have used the p3 over the sea from  ...

"What should be the conclusion in this case.. Do i fly safe if i charge 100% ? "

Current thinking is that you should charge your batteries fully, say the night before the flight, and only take off on a full battery. If you fly for some time and then land, put a fresh, fully charged battery in for the next flight.

I don't believe the altitude has anything to do with the problem, other than the fact that the air temperature would be colder.

hummingbird.uav Posted at 2016-2-19 13:19
I can point you to my video which shows what happens when a flight is made with a partially charged  ...

I watched this video a while back and it really showed me why it is important to fly with a full battery. One of those "Ah Ha!" moments that I've just committed to the checklist now. VERY well done, hummingbird....and thanks for sharing it!

Nobody is mentioning one of the most common reasons a Phantom may "fall from the sky".... in a moment of excitement its possible to move both sticks to opposite bottom corners and execute an engine disarm while in flight. Personally I think this "feature" should be removed but I understand the reason to have an emergency engine stop method while the bird is in the air.

Regardless, its a possible cause and something to be careful you don't do.

Battery!  I copied one of my posts from the Inspire 1 group

We have the mystery of the batteries dropping for no reason right? There have been many posts including me regarding battery problems.  
So, I set out to see if I could duplicate the sudden battery drop.
Okay, I set three (3) fully charged batteries aside  for three weeks without touching them. All of these batteries are set for 10 days on the App regarding the auto discharge cycle assuming this is controlled by the intelligent battery chip and firmware.
First I checked each battery by pushing the power button to see the status of each one. I got three solid green LED's and the fourth one was blinking. Based on the LED's each of them looked the same.

The next thing I did was to install one of the batteries into my inspire 1, then set up my remote and IPad. Turned on everything and then connected. Looking at the battery screen in the GO App my first battery was showing 80% charge, about 3.98 volts per cell . Now I started the Inspire while leaving the battery page open on my screen to watch. Put the bird into a 10 foot hover and cycled the gear up. The progress bar said I had about 10.20 minutes of flight time and everything was looking good.  I decided to lower the landing gear just to be safe and continued to watch the battery as it went to 76%. (pretty boring stuff right) one minute, started on the second minute and everything was fine.  I was playing with the camera gimbal and cycled the landing gear again up and then back down at about 1 minute and 15 seconds into the flight  and right.... then at about 1 minutes and 21 seconds the battery dropped without warning to 5% the red LED was flashing and the inspire was landing in only seconds. I have the flight log to prove this (but not sure how to copy the file yet). Pretty scary right. So I shut everything down and began getting my second battery ready to go.

Same process and started up the Inspire with the battery showing 76% bah bah bah... this time I did not even get the landing gear raised up. I watched the battery monitor and two of the six cells dropped within 35 seconds into the red. So I did not chance this one over a minute, set it down and shut it off. Funny thing is when the Inspire was setting on the ground motors off, the battery showed normal voltage (without load). Start the motors and the cells immediately dropped to undesired levels.

I put the final battery into the Inspire and this one acted differently than the other two. Started up with 80% battery and all cells were within about 3.98volts The progress bar showed11:44 minutes flight time. I flew this battery while watching the monitor and the cells were consistent and everything seemed to work fine. Keep in mind that I was not going to get carried away (just hovered in one place) I was able to fly this battery for 9 minutes and shut it down with 24% battery left showing.  The flight power progress bar was consistent throughout the flight (not working very hard) and keeping it is a safe place for the experiment.

All of these batteries have worked well and no issues before the test and now I can see why we are hearing about sudden voltage drops from people using the tools we have in hand. If you just rely on the green LED's to tell us the battery condition it would be an mistake.
I always charge my batteries (top off) before I go to fly. It seems that the LED lights do not really show the state of the battery after it has been in the self discharge mode. Each battery has variable's that could be due to usage and useful lifespan. Temperature is another factor on total operational time.
ALWAYS charge your batteries before you start the flying session.  


TB47 Battery #1 has 9 flights
TB 47 Battery #2 has 10 flights
TB 47 Battery # 3 has 3 flights

I will post some screen shots and the flight log once it get this off my iPad.

Thanks for your attention and I hope this will help us in some way.
link


Rich

RichJ53 Posted at 2016-2-20 12:39
Battery!  I copied one of my posts from the Inspire 1 group

We have the mystery of the batteries dr ...

Some interesting observations, thank you.

It seems that the lesson for all of us is not to fly with batteries which have been partially discharged in previous flights.  Personally, I do reuse a partially discharged battery (50-70% remaining)  provided the previous flight was only 15 minutes or so prior and I've not experienced any unusual battery issues. I'm assuming that, in this case, the battery would still be warm and all readings would still be correct but I'd be interested in hearing from anyone who has had issues reusing a battery after only a short delay.

ghtracey Posted at 2016-2-20 11:55
Nobody is mentioning one of the most common reasons a Phantom may "fall from the sky".... in a momen ...

I'm with you mate, and think that so called safety feature should be removed, it's probably caused more damage then its saved.
Is this feature in a normal  aircraft ?? I don't think so lol.

ghtracey Posted at 2016-2-20 11:55
Nobody is mentioning one of the most common reasons a Phantom may "fall from the sky".... in a momen ...

Not really the case here, as yul said, he had just given the aircraft a "fast forward ascend command", meaning both sticks would have been in the opposite position to a CSC command.

Sorry for your accident. When it crashed 4 months ago, did you contact the support center?
If you update the aircraft to 1.6 it has battery management software for cold weather operations and it looks like you are in a cold area.
I will have someone look at your DAT file Monday and let you know what happened.

JockC Posted at 2016-2-19 18:24
Some interesting observations, thank you.

It seems that the lesson for all of us is not to fly wi ...

Yes, these are not intended to throw DJI under the bus, it is to raise awareness. I hope that the next firmware update has some refreshing changes for us regarding the battery system. I have not had any problems with my P3P and only some minor issues with the inspire 1. All in all they are great machines

I hope Ken can share the DJI findings for your incident, this would be very interesting to hear back from them after they look at the logs

Rich

ghtracey Posted at 2016-2-20 11:55
Nobody is mentioning one of the most common reasons a Phantom may "fall from the sky".... in a momen ...

This is easily checked, just replay the flight record, but turn on the joystick overlay (with the button on the bottom of the screen that looks like a RC controller, second from the left).  As you replay the flight it shows your stick inputs, and you can see if you inadvertently applied a CSC.  I' not sure why these are not displayed by default.

ghtracey Posted at 2016-2-20 02:55
Nobody is mentioning one of the most common reasons a Phantom may "fall from the sky".... in a momen ...

Thank U all for reply.  In this particular situation we can see in the dat log  that the craft lost power in air. If we stop the motors in the air and p3 drop, the log does not stop and p3 keep recording until battery is removed or power button is pressed or p3 power down from the crash, but that will be on the grownd in the last moment of the log. I think this case is definitely about p3 power drop in mid air.

DJI-Ken Posted at 2016-2-20 05:25
Sorry for your accident. When it crashed 4 months ago, did you contact the support center?
If you up ...

Thank you Ken for reply.
No Ken I did not contact support. I'm a practical guy, I'm From Romaina. I don't think we have here support from DJI and sending the package to US and the low rate of accepted crash refund from DJI made me think that I will only be losing time and money on packaging .

But sure  now when I repaired my p3 and i know that only the gimbal is affected by the crash i could send my gimbal only for repair if DJI consider they can help me. I could only afford advanced gimbal and camera to buy and change the 4k pro version I had. So it would be nice to have my pro gimbal repaired.

yul Posted at 2016-2-20 15:55
Thank you Ken for reply.
No Ken I did not contact support. I'm a practical guy, I'm From Romaina. I ...

Your closest DJI repair center is in Germany so I don't the cost for you to ship it there.
But the DAT data will tell what happened.

Thank you Ken.  We all wait the log information.

DJI-Ken Posted at 2016-2-20 10:22
Your closest DJI repair center is in Germany so I don't the cost for you to ship it there.
But the ...

Hi Ken. Can you please look at dat log?

Im still waiting for the log data to tell me. if there was battery problem. or other error.. i need the answare. to.  feel. safe while flying. tks