Lost Mavic Pro

[crlmjohnson]

If the drone lost the battery in flight, then the drone glided a little before it actually came down, so you might have a pretty big area to cover to tried and located your drone. Hopefully it is not caught up on something like a tree, roof, line. Etc.

 

[Marko9219]

If the drone lost the battery in flight, then the drone glided a little before it actually came down, so you might have a pretty big area to cover to tried and located your drone. Hopefully it is not caught up on something like a tree, roof, line. Etc.

I'm no aerodynamic engineer, but I suspect that because both objects are moving at identical speed and identical altitude when they separated, and because both objects would have a somewhat equally terrible drag coefficient, then both objects would have a somewhat similar trajectory to the ground. Point of impact for both would be very close I would think. Supposedly, they were only 300ft or so in the air at separation. That doesn't give much space for aerodynamic dispersion while falling.

 

[crlmjohnson]

I agree.

I hope you can find your drone.

 

[Chris1960]

Yeah, I'm pretty curious about this also. Especially from a new member without any history. Tell us how you suppose the drone got inverted to allow the battery to fall free, and then got separated from the battery when both are descending in free fall? I would suspect that the instant the electrical connection was broken the thrust would cease, so both objects would glide like a safe. One of the rules of flight is maintaining line of sight still isn't it?

Is the flight log posted yet?

Reason for new member was to seek advice from experts!!.Don't know if drone was inverted however it was in line of site and when battery bounced of house roof attention was drawn away from drone. Flight log shows no errors on part of myself. Drone was directly above me on RTH.And yes I would also like to know how the battery separated from the drone (Mystery )

 

[Chris1960]

If the drone lost the battery in flight, then the drone glided a little before it actually came down, so you might have a pretty big area to cover to tried and located your drone. Hopefully it is not caught up on something like a tree, roof, line. Etc.

I have searched approx 100m radius of where battery landed in gardens fields house roofs etc with no success

 

[dylanthecat]

And no one has ever admitted to it

I admitted to that a few months ago. First flight. Took off and got a warning on the screen about battery. Landed and checked. Sure enough it was not clicked fully in. Got lucky. Now if I had crashed I would not have admitted to it, since then there is no way to prove it.

 

[sar104]

Reason for new member was to seek advice from experts!!.Don't know if drone was inverted however it was in line of site and when battery bounced of house roof attention was drawn away from drone. Flight log shows no errors on part of myself. Drone was directly above me on RTH.And yes I would also like to know how the battery separated from the drone (Mystery )

The purpose of asking for the log in this case is not to figure out what you did wrong, but to figure out what may have caused the battery ejection and the resulting trajectory of the aircraft body. That was the advice that you received from the "experts". If you don't want to post it then that's fine, in which case there is nothing more anyone here can do for you.

 

[dylanthecat]

Chris1960, Im curious why you won't post the flight logs. Sar104 is really good at extrapolating the position of a copter after loss of data. Give him a chance.

 

[Chris1960]

Chris1960, Im curious why you won't post the flight logs. Sar104 is really good at extrapolating the position of a copter after loss of data. Give him a chance.

Not that I don't want to post flight log just that I have tried but can't I am quite willing to post flight log I have nothing to hide lol

 

[sar104]

Not that I don't want to post flight log just that I have tried but can't I am quite willing to post flight log I have nothing to hide lol

What happened when you tried to post it? You presumably have retrieved the flight log because you mentioned that you had looked at it. It's a simple txt file so it can be uploaded directly to this website, or you can post a link to Phantomhelp or Airdata if you used one of those sites to view it.

 

[draver]

Reason for new member was to seek advice from experts!!.Don't know if drone was inverted however it was in line of site and when battery bounced of house roof attention was drawn away from drone. Flight log shows no errors on part of myself. Drone was directly above me on RTH.And yes I would also like to know how the battery separated from the drone (Mystery )

Again I apologize but I'm still confused. Your drone was at 100m RTH in line of sight when you heard the battery hit a house? If as you stated, it was in sight when the battery hit the house, it had to be falling also. Several seconds (4+) must have elapsed between when the battery fell then hit the house. How could you not see the drone falling also if you were watching it? It should have been pretty obvious something was wrong, and I also don't know how to get a Mavic Pro into inverted flight so the battery could fall clear.

 

[David Hasselhoff]

Again I apologize but I'm still confused. Your drone was at 100m RTH in line of sight when you heard the battery hit a house? If as you stated, it was in sight when the battery hit the house, it had to be falling also. Several seconds (4+) must have elapsed between when the battery fell then hit the house. How could you not see the drone falling also if you were watching it? It should have been pretty obvious something was wrong, and I also don't know how to get a Mavic Pro into inverted flight so the battery could fall clear.

 

[Chris1960]

Flight data attached

 

[Chris1960]

What happened when you tried to post it? You presumably have retrieved the flight log because you mentioned that you had looked at it. It's a simple txt file so it can be uploaded directly to this website, or you can post a link to Phantomhelp or Airdata if you used one of those sites to view it.

Posted flight log I think !! lol

 

[Moose1967]

Sounds to me like a bird of prey could have taken your drone - once flying I had a large bird take two swipes at my Mavic Pro - think it was a raven. It's very possible a bird grabbed it, dislodging the battery, and maybe flew off with it.

It's something you have to consider. See many birds that day? Were you recording when the incident happened? Did you review the footage if you have it?

 

[Meta4]

Flight data attached

Try this:
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it gives you.

 

[Chris1960]

Sounds to me like a bird of prey could have taken your drone - once flying I had a large bird take two swipes at my Mavic Pro - think it was a raven. It's very possible a bird grabbed it, dislodging the battery, and maybe flew off with it.

It's something you have to consider. See many birds that day? Were you recording when the incident happened? Did you review the footage if you have it?

There were a few birds about. Not recording at time was just giving friend a quick demo

Try this:
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it gives you.

Hopefully flight log now uploads thanks

 

[sar104]

Posted flight log I think !! lol

Yes - got it. Stand by.

 

[sar104]

Based on the flight data there was a reasonable breeze blowing out of the NNE (~ 10°). It looks to be around 7 or 8 m/s at 120 m AGL.




That's going to move the aircraft some distance during descent, especially without the added weight of the battery. I can do some more detailed simulations later, but a back of the envelope calculations suggests a drift of 20 - 30 m downwind - i.e. to the SSW. It could have hit the roof of one of those houses to the south or cleared them completely.

 

[Chris1960]

Based on the flight data there was a reasonable breeze blowing out of the NNE (~ 10°). It looks to be around 7 or 8 m/s at 120 m AGL.

View attachment 58094


That's going to move the aircraft some distance during descent, especially without the added weight of the battery. I can do some more detailed simulations later, but a back of the envelope calculations suggests a drift of 20 - 30 m downwind - i.e. to the SSW. It could have hit the roof of one of those houses to the south or cleared them completely.

View attachment 58095

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.