New Phantom 3 Pro failed to RTH

[David Moritz]

Hi all

I am new to the so please be nice. I purchased the Phantom 3 Pro last week whilst in the US (I live in the UK). I have had a few practice flights in my local park and have successfully taken off, flow and landed (and got some great shots already). Yesterday I took it to my parents to show off and the drone announced a 'critically low power' and the screen went black about 40 seconds after takeoff. I started to panic, however hit the RTH button. The drone did not RTH. It landed 1km away in a tree. Fortunately I was able to retrieve it using the GPS on my phone, and the drone suffered just a few scratches (and luckily didn't harm the camera or anyone nearby).

I am concerned why the RTH did not work. I have just taken the drone back to the park and hitting the RTH simply lands the drone, however I am aware that if you are within 20m, it simply lands as opposed to RTH. What I don't get was why yesterday, it decided to land rather than RTH when at such a distance away. To be precise it was 360m away, and I can see from the log that RTH was initiated however it then landed almost immediately.

Any advice would be much appreciated. I am worried it could be a fault, but hoping to be proved wrong.

Thank you
David

 

[RedHotPoker]

David,
Firstly, welcome to the forum and Phantom 3 family.
Please Excuse me, if I should sound or seem harsh, but this is a serious situation. Before you took off, had you done a cold IMU calibration, and a good compass calibration? Also, did it say Home Point has been Updated, Please Check it on the map. These are very important steps that teach the drone where to return, to its home point. If this and the other important parameters aren't set correctly, as established right up front. Well disastrous and varied result may and will, occur. Consider yourself lucky it wasn't damaged further, or had resulted in a fly away, often never to be found.
Am I mistaken? and If so, my apology.

RedHotPoker

 

[matwelli]

You were 1km away and got a " critical power" warning ?
I believe when the battery is that low it will land as it can-not make it back to home.

 

[2fast4u]

Critical low voltage error will initiate auto landing. Rth will not override, only if you cancel auto landing you can bring it back.

 

[2fast4u]

Note a lot of people are confusing low battery with critical low voltage. Low battery will force a landing only at 10%, low voltage often happens when flying a not fully charged battery and then mostly around 50% battery remaining. Lots of different threads about it.

 

[Zee]

Was it a fully charged battery? I think when you got the critical low power, it initiated auto land. It can't RTH due to low battery.

Always fly with fully charged battery.

 

[Meta4]

Understanding RTH is critical to safe flying.
There are three pages on it in the manual.
Read and understand it then go to an open area, fly 100 feet away and try it out a couple of times.
Learn how to initiate RTH and how to cancel it and resume control.
Then when you need RTH, you'll know what to do.

 

[David Moritz]

David,
Firstly, welcome to the forum and Phantom 3 family.
Please Excuse me, if I should sound or seem harsh, but this is a serious situation. Before you took off, had you done a cold IMU calibration, and a good compass calibration? Also, did it say Home Point has been Updated, Please Check it on the map. These are very important steps that teach the drone where to return, to its home point. If this and the other important parameters aren't set correctly, as established right up front. Well disastrous and varied result may and will, occur. Consider yourself lucky it wasn't damaged further, or had resulted in a fly away, often never to be found.
Am I mistaken? and If so, my apology.

RedHotPoker

Hi

I had done a full IMU calibration and ensured that the home point was updated. This is confirmed in the log.

 

[David Moritz]

Was it a fully charged battery? I think when you got the critical low power, it initiated auto land. It can't RTH due to low battery.

Always fly with fully charged battery.

Thanks for this. This battery was brand new and one of my concerns was that despite all four lights flashing when charging, it was not fully charged.

 

[2fast4u]

If you upload your log to healthydrones and post a link we can see the exact error message, where that happened and what happened right after. It will also show battery % at takeoff etc.

 

[stealthbomber]

Thanks for this. This battery was brand new and one of my concerns was that despite all four lights flashing when charging, it was not fully charged.

When the four lights are flashing when charging it means it's still charging, only when all lights stop blinking and no lights are on means it's fully charged!

 

[CCDD]

All 4 lights will go out when it's fully charged,

 

[kandglawn]

Did u push the return to home button twice like when powering on the controller

 

[David Moritz]

If you upload your log to healthydrones and post a link we can see the exact error message, where that happened and what happened right after. It will also show battery % at takeoff etc.

Thank you. Here is the link: HealthyDrones.com - Innovative flight data analysis that matters

 

[David Moritz]

Did u push the return to home button twice like when powering on the controller

I pushed it and held it until the voice feedback stated it was RTH.

 

[David Moritz]

Here is the log: HealthyDrones.com - Innovative flight data analysis that matters

 

[Wingfan04]

Cell 1 on your battery is having issues. And besides the problems you were having, please tell me you were not flying in the wind the data is showing. 31 MPH wind with 53 MPH Gusts!!!!

 

[Wingfan04]

and it says your takeoff battery was 50% unless your battery was charged earlier that day This is another Big NO NO always takeoff with a fully charged battery the same day

 

[2fast4u]

Couple of things stand out. You got a low power, not low voltage. That is strange considering you took off with 50% and landed with 25 a while later. It says the battery was charged 0 times. Do you have multiple and mixed them up? Used this one fresh out of the box? After the first error it says auto landing initiated but you kept flying forward by the looks of it. You did initiate rth but It didnt come back, that is really strange but maybe autolanding overrules. It kept going (you will have control during auto landing but limited) and it looks like it remained at altitude till the second low power warning. Then it goes down and you lose signal at 10m height that is the only logical bit. Only thing I can think of is that your battery was never (fully or at all) charged and therefore properly calibrated. These things are sensitive so that may have caused your power error. I would open a case with DJI to have the facts checked. And you might want to review your next flights in healthydrones to check thos cell errors. If they consistently appear in large amountd there may be an issue but my guess is they will be gone after your next full charge.

 

[David Moritz]

Couple of things stand out. You got a low power, not low voltage. That is strange considering you took off with 50% and landed with 25 a while later. It says the battery was charged 0 times. Do you have multiple and mixed them up? Used this one fresh out of the box? After the first error it says auto landing initiated but you kept flying forward by the looks of it. You did initiate rth but It didnt come back, that is really strange but maybe autolanding overrules. It kept going (you will have control during auto landing but limited) and it looks like it remained at altitude till the second low power warning. Then it goes down and you lose signal at 10m height that is the only logical bit. Only thing I can think of is that your battery was never (fully or at all) charged and therefore properly calibrated. These things are sensitive so that may have caused your power error. I would open a case with DJI to have the facts checked. And you might want to review your next flights in healthydrones to check thos cell errors. If they consistently appear in large amountd there may be an issue but my guess is they will be gone after your next full charge.

Thanks for the thorough reply. I had put this brand new battery on charge, however took it off charge when the four lights were flashing. I now realise that it is not charged until all four lights go out. I guess this is why the log says '0' charges. I will keep checking and open a case with DJI if the error persists. In your opinion, is it the low power issue that cause the drone to auto land as opposed to RTH?

Thank you