Lost Mavic Pro

Irvine · Jan 7, 2019

How did the battery come off 3as you flying upside down or a

Irvine · Jan 7, 2019

Chris1960 said:
I recently lost my Mavic Pro whilst flying at approx 100m with RTH activated my battery came crashing to the ground and drone nowhere to be found. Was wondering if this is something any other pilot had experienced

Hello was wondering how the battery came off either the drone was upside down or there was a lot of vibration and shook the battery off. I have a mavic platinum I can't really see how the battery came off. Good luck keep searching and do what the others say to do. Regards Irvine

David Hasselhoff · Jan 7, 2019

Maybe get up on the roof and check?

Mossiback · Jan 7, 2019

I am assuming you retrieved the battery. Is there any evidence of swelling?

sar104 · Jan 7, 2019

Irvine said:
Hello was wondering how the battery came off either the drone was upside down or there was a lot of vibration and shook the battery off. I have a mavic platinum I can't really see how the battery came off. Good luck keep searching and do what the others say to do. Regards Irvine

There's likely no mystery about what happened to the battery. The fact that it separated in mid-air unambiguously means that it was not properly latched. It had just commenced autolanding descent. The first thing that will have happened is that it shifted enough to disconnect and cut the power. Then the aircraft will tumble and, when inverted, the denser battery can fall out.

sar104 · Jan 7, 2019

Chris1960 said:
Thanks for you help that's great.The impact estimate you mention is the house I was flying from, we expected to go to the front of the house and find the drone on the road but no sign. it's like it's disappeared so confused as to why it can't be found.

The complication is the aerodynamic drag coefficient for a a Mavic with no battery. I don't have a good number for that. I'll run some simulations with different values and see what the reasonable upper limit for drift might be.

JDawg · Jan 7, 2019

My guess is someone grabbed it. Did you have your contact info attached? If it hit a house it made enough noise to cause someone to investigate.

Chris1960 · Jan 7, 2019

JDawg said:
My guess is someone grabbed it. Did you have your contact info attached? If it hit a house it made enough noise to cause someone to investigate.

That's what we think it just doesnt dissapear without trace

Chris1960 · Jan 7, 2019

sar104 said:
The complication is the aerodynamic drag coefficient for a a Mavic with no battery. I don't have a good number for that. I'll run some simulations with different values and see what the reasonable upper limit for drift might be.

Thanks for all the info and help

Chris1960 · Jan 7, 2019

Mossiback said:
I am assuming you retrieved the battery. Is there any evidence of swelling?

No evidence of swelling just smashed to pieces

Chris1960 · Jan 7, 2019

sar104 said:
There's likely no mystery about what happened to the battery. The fact that it separated in mid-air unambiguously means that it was not properly latched. It had just commenced autolanding descent. The first thing that will have happened is that it shifted enough to disconnect and cut the power. Then the aircraft will tumble and, when inverted, the denser battery can fall out.

Always check and double check which is a must when spent the large amount of money on the equipment

sar104 · Jan 7, 2019

Chris1960 said:
Thanks for all the info and help

Looking in a bit more detail suggests that it might have travelled somewhat further - possibly up to 80 m.

Chris1960 · Jan 7, 2019

sar104 said:
Looking in a bit more detail suggests that it might have travelled somewhat further - possibly up to 80 m.

View attachment 58118

Thanks just about give up hope of fi ding but well worth another look

JDawg · Jan 7, 2019

Put out a flier if you don't find it, someone has it for sure.

sar104 · Jan 7, 2019

Chris1960 said:
Thanks just about give up hope of fi ding but well worth another look

Can you retrieve the txt log from your mobile device? I'd like to compare my wind speed and direction calculations with Airdata's wind algorithm, but their version is not working properly with DAT file input.

TXT log instructions: DJI Flight Log Viewer | Phantom Help

Chris1960 · Jan 7, 2019

sar104 said:
Can you retrieve the txt log from your mobile device? I'd like to compare my wind speed and direction calculations with Airdata's wind algorithm, but their version is not working properly with DAT file input.

TXT log instructions: DJI Flight Log Viewer | Phantom Help

Sorry unable to retrieve txt log fro. my phone

Meta4 · Jan 7, 2019

Chris1960 said:
Sorry unable to retrieve txt log fro. my phone

There are instructions in post #36

draver · Jan 7, 2019

Chris1960 said:
No evidence of swelling just smashed to pieces

I hope you're not storing the remains anywhere indoors or around any flammables. It could have caught your roof on fire, and still has the potential for wreaking havoc. Are the inner cells exposed?

Chris1960 · Jan 8, 2019

draver said:
I hope you're not storing the remains anywhere indoors or around any flammables. It could have caught your roof on fire, and still has the potential for wreaking havoc. Are the inner cells exposed?

Disposed of in correct manner

draver · Jan 8, 2019

Sounds good, what is the requirement there for that? It would be interesting if you had a pics of the battery that you could share with us. Also, was there any damage to your roof? It would seem that the terminal velocity would have been huge and could have punched a hole or caused a leak possibly. Quite the high density projectile, LOL. You didn't describe what was visible inside, if anything. Could you count the cells, were they damaged as far as you could tell?