Theory explaining how Mavic could drop down from skies... Your thoughts, please...

[TTFullTimer]

Power loss was also my first thought but there will be a "Lost Connection" message recorded on the logs... I have never seen that... If only the sensors in charge for altitude (barometer, sonar, accel. or any combination) freeze for some seconds maybe that would not cause a crash, maybe just instability for seconds... The pilot would not "sense" or realise that...

No power no recording

Power loss was also my first thought but there will be a "Lost Connection" message recorded on the logs... I have never seen that... If only the sensors in charge for altitude (barometer, sonar, accel. or any combination) freeze for some seconds maybe that would not cause a crash, maybe just instability for seconds... The pilot would not "sense" or realise that...

 

[Alex ROV]

No power no recording

The messages and data are recorded on device (smartphone or tablet), not (only) inside the drone...

 

[Robbyg]

The messages and data are recorded on device (smartphone or tablet), not (only) inside the drone...

If the drone losses power there is no data to be sent to the phone.
This sudden falling out of the sky issue was hashed and proven about 3 months ago. It's the battery not being clipped in properly and losing contact momentarily during the flight.

Rob

 

[Alex ROV]

If the drone losses power there is no data to be sent to the phone.
This sudden falling out of the sky issue was hashed and proven about 3 months ago. It's the battery not being clipped in properly and losing contact momentarily during the flight.

Rob

Yes! No data going from aircraft to the app BUT the app will write on its logs files that the connection was lost with aircraft... There's no "Lost Connection" warning or message on the logs...

Even after the crash happens on the ground and the aircraft turns into pieces the lost connection is never recorded... What shows that the flight had already been considered finished before the crash...

 

[Pablo]

I too think that its admirable work done by Alex ROV, but I'm still perplexed on where the "Mavics dropping from the sky" derives from. I've been lurking on these forums for quite some time and never seen wide-spread "mavic dropping from sky issues", Karma..yes. Spark...yes. In regards to DJI providing us (the consumer) with any data pertaining to failure rates is ludicrous. What other consumer product(s) manufacturer publicly publishes failure rate information.

I'm not quite sure you've grasped the concept of lurking. You've got over 1,000 posts

 

[Kilrah]

What shows that the flight had already been considered finished before the crash...

Nope, the only thing that would indicate the flight was considered finished is a message stating that. The lack of anything can't say much, for all we know it's only logging what it receives from the aircraft, so if it doesn't send anything you don't get anything. The common analysis tool that tell you "signal lost for X" likely just looks at the length of the gap between 2 messages.

 

[Static8]

I remember not have my battery was not completely clicked in and I could have easily lost power to the MAVIC in flight but I was just doing a 3 min flight...I was very lucky , If I would have gone into SPort mode for example, I would have lost the MAVIC.

 

[Chadnovz]

I must be living in a vacuum, because I haven't been aware of any widespread issues of Mavics "dropping out of the sky". With that said, there are a fair amount of reports that the Sparks have this issue.

I agree. My friends spark crashed into the lake lol

 

[Reed]

I remember not have my battery was not completely clicked in and I could have easily lost power to the MAVIC in flight

That also occurred to me.
Therefore, I marked a line with a lightening color on the battery. If the battery is not clipped in well, you still see the marking color indicating the danger.

 

[MrMavic]

Seems like there's a lot of time spent here trying to rule out human pilot error when human error is most likely the cause. Maybe more time spent learning the do's and don'ts of flying would be time better spent.

 

[Tom w]

Please guys... It might be very important...

I have developed a theory that explains why and how the Mavics are dropping down from the skies... I would like to hear your thoughts and contributions, please...

I have read lots of flight data logs that were published by its unffortunate pilots, trying to find any points in order to clarify what had happened, there 2 or 3 details that all events have in common, but there is one that highlight my attention since the first reported case: the last system message is always "MAVIC HAS LANDED"

Normally, in any other case of crashing, the last message is "LOST CONNECTION"... Even in case of battery disconnection, the app and remote controller loose connection with aircraft and "LOST CONNECTION" is the last recorded message in the log, which is correct. But with the dropping down events this message is never recorded, instead the last one says that the aircraft has landed and that means the end of a normaal regular flight.

My theory: the system thinks that Mavic has landed, or in other words, Mavic is touching a surface, then, when the pilot commands to go down, the motors go to shutdown, as is designed to happen.

Now, lets think: how does Mavic know that she has landed? Using her barometer... The air pressure given by altitude is given to the system by her barometer, and the computer uses this data to maintain her altitude. So, saying this, how does the computer know that Mavic is touching the ground (landed)? Because the pilot moves the stick down and the Mavic altitude DOES NOT change, in other words, the data that computer receives from her barometer DOES NOT change...

And what happens after, when the pilot keeps the stick down after landind? Motors shutdonw!

Long story short, my theory is that the barometer freezes its data in middle flight, middle air, making the computer assume that Mavic has landed... Then the motors shutdown as expected with stick down command.

I really would like to hear from DJI about this theory...

Now, in order to try to avoid this serious issue... Could we avoid that if we leave the Landing Protection feature always ON? I believe that in this case the system would ask the pilot to confirm the landing...
I would like to move from theory to practise... I will try to simulate that, holding the Mavic from the top, with my hand, not allowing her to go down... Then I will command the stick down. She will think that has landed and shut down the engines after short seconds. If that experiment happens, I believe we prove the cause of the problem.

Please, sorry by the very long text... But I would like to hear your thoughts... And if any of you guys could make contacts and forward this message to DJI techs, it would be much appreciate.

Many thanks!

UPDATE:

- Thanks everybody for the comments... Lets keep it, please, and try to reach DJI techs... Another piece of advice I believe we can take from here:
NEVER DO FULL STICK DOWN DURING THE FLIGHT...

- Yes! Mavic does shutdown the motors "thinking" that has landed when hand catched... So, if a glitch happens in middle air and the sensors dont update the altitude the Mavic will assume that has landed and possibly shutdown the motors... That's my theory...

- Combination Stick Command in middle flight would be shown on logs... But I have never seen CSC in these events...

Well heres my experience I do hold my elevator or throttle full down many times and its not dropped out of the shy..I fly 3 batters ever night ,weather permitting..and have lost signal also ,,no problems with mine so far,,I have put hundreds of miles and still going and I do not need a wifi connection to fly..
Now some was haveing troubles with IPADs when flying,,jerking or freezing,,well when that happens reboot the tablet..
thank you and happy landings
thomas

 

[Ignacio]

I am going to buy a DJI MAVIC. If you have your mavic drop out of your sight, is there any way you can track it to find where it landed and recover it?

 

[iMario]

@Ignacio Well, you always have a flight path on your phone app. That one displays the last known position of your drone, so locating it should not be that much of a problem. Also, depends greatly on the terrain configuration.

 

[Mike Smith]

Please guys... It might be very important...

I have developed a theory that explains why and how the Mavics are dropping down from the skies... I would like to hear your thoughts and contributions, please...

I have read lots of flight data logs that were published by its unffortunate pilots, trying to find any points in order to clarify what had happened, there 2 or 3 details that all events have in common, but there is one that highlight my attention since the first reported case: the last system message is always "MAVIC HAS LANDED"

Normally, in any other case of crashing, the last message is "LOST CONNECTION"... Even in case of battery disconnection, the app and remote controller loose connection with aircraft and "LOST CONNECTION" is the last recorded message in the log, which is correct. But with the dropping down events this message is never recorded, instead the last one says that the aircraft has landed and that means the end of a normaal regular flight.

My theory: the system thinks that Mavic has landed, or in other words, Mavic is touching a surface, then, when the pilot commands to go down, the motors go to shutdown, as is designed to happen.

Now, lets think: how does Mavic know that she has landed? Using her barometer... The air pressure given by altitude is given to the system by her barometer, and the computer uses this data to maintain her altitude. So, saying this, how does the computer know that Mavic is touching the ground (landed)? Because the pilot moves the stick down and the Mavic altitude DOES NOT change, in other words, the data that computer receives from her barometer DOES NOT change...

And what happens after, when the pilot keeps the stick down after landind? Motors shutdonw!

Long story short, my theory is that the barometer freezes its data in middle flight, middle air, making the computer assume that Mavic has landed... Then the motors shutdown as expected with stick down command.

I really would like to hear from DJI about this theory...

Now, in order to try to avoid this serious issue... Could we avoid that if we leave the Landing Protection feature always ON? I believe that in this case the system would ask the pilot to confirm the landing...
I would like to move from theory to practise... I will try to simulate that, holding the Mavic from the top, with my hand, not allowing her to go down... Then I will command the stick down. She will think that has landed and shut down the engines after short seconds. If that experiment happens, I believe we prove the cause of the problem.

Please, sorry by the very long text... But I would like to hear your thoughts... And if any of you guys could make contacts and forward this message to DJI techs, it would be much appreciate.

Many thanks!

UPDATE:

- Thanks everybody for the comments... Lets keep it, please, and try to reach DJI techs... Another piece of advice I believe we can take from here:
NEVER DO FULL STICK DOWN DURING THE FLIGHT...

- Yes! Mavic does shutdown the motors "thinking" that has landed when hand catched... So, if a glitch happens in middle air and the sensors dont update the altitude the Mavic will assume that has landed and possibly shutdown the motors... That's my theory...

- Combination Stick Command in middle flight would be shown on logs... But I have never seen CSC in these events...

My answer may be over simplified but is pilot error. I have had my Mavic drop from the sky because I hit The land icon instead of return home by accident, they are very close on the screen. Fortunately I realized in time to recover.

 

[BigDaddy505]

Thank you. Your entire post is most helpful.
I wish to add. When you witness crashes on YouTube and the like, 99.999999% of the time you hear these guys complaining and saying how DJI Mavic Pro is so bad.

HOWEVER! !!!! Go back and watch their videos they post. What's the obvious problem??? These absolute idiots are completely disabling all the safety measures on the drone. They deserve every loss and every crash. There was a video on YouTube and no, now I can't find it again to show you. But this guy goes through this tutorial on how to make your drone faster and fly higher if you follow his suggestions. How do you think these irresponsible jackasses fly at 4500 meters? It's so impressive huh? What happens when that drone flies straight into an commercial airline engine? It's feasible. What aircraft could handle a catistofic event like that? How funny would it be to watch 300 plus souls parish cause you want to look cool on YouTube? You belong in jail for life for attempted premeditated murder. PERIOD! You purposely removed the altitude restriction, you agreed you were follow all FAA guidelines and you, with intent, placed lives in harms way. Absolutely crystal clear you set out to hurt people and jeopardize their lives in your neglectful actions.

It's *** holes like that that give us responsible pilots bad names and reputations.

 

[Static8]

Thank you. Your entire post is most helpful.
I wish to add. When you witness crashes on YouTube and the like, 99.999999% of the time you hear these guys complaining and saying how DJI Mavic Pro is so bad.

HOWEVER! !!!! Go back and watch their videos they post. What's the obvious problem??? These absolute idiots are completely disabling all the safety measures on the drone. They deserve every loss and every crash. There was a video on YouTube and no, now I can't find it again to show you. But this guy goes through this tutorial on how to make your drone faster and fly higher if you follow his suggestions. How do you think these irresponsible jackasses fly at 4500 meters? It's so impressive huh? What happens when that drone flies straight into an commercial airline engine? It's feasible. What aircraft could handle a catistofic event like that? How funny would it be to watch 300 plus souls parish cause you want to look cool on YouTube? You belong in jail for life for attempted premeditated murder. PERIOD! You purposely removed the altitude restriction, you agreed you were follow all FAA guidelines and you, with intent, placed lives in harms way. Absolutely crystal clear you set out to hurt people and jeopardize their lives in your neglectful actions.

It's *** holes like that that give us responsible pilots bad names and reputations.

Yup there are many out there and reason for all the stupid rules and laws today. Still there are more responsible RC enthusiasts out there vs stupid ones, like drunk drivers, people who break the speed limit...We are all paying for it because of these ...holes

 

[Pol]

Thank you. Your entire post is most helpful.
I wish to add. When you witness crashes on YouTube and the like, 99.999999% of the time you hear these guys complaining and saying how DJI Mavic Pro is so bad.

HOWEVER! !!!! Go back and watch their videos they post. What's the obvious problem??? These absolute idiots are completely disabling all the safety measures on the drone. They deserve every loss and every crash. There was a video on YouTube and no, now I can't find it again to show you. But this guy goes through this tutorial on how to make your drone faster and fly higher if you follow his suggestions. How do you think these irresponsible jackasses fly at 4500 meters? It's so impressive huh? What happens when that drone flies straight into an commercial airline engine? It's feasible. What aircraft could handle a catistofic event like that? How funny would it be to watch 300 plus souls parish cause you want to look cool on YouTube? You belong in jail for life for attempted premeditated murder. PERIOD! You purposely removed the altitude restriction, you agreed you were follow all FAA guidelines and you, with intent, placed lives in harms way. Absolutely crystal clear you set out to hurt people and jeopardize their lives in your neglectful actions.

It's *** holes like that that give us responsible pilots bad names and reputations.

I wish there was a law that would put those idiots behind bars for the rest of there lives

 

[dewster]

Executing the CSC command in flight could be one:

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Here's a wilder theory:

Descending in a strong updraft makes the sensors of the Mavic think that it landed causing the motors to shut down. This is just a wild theory so no one get bent out of shape. For something so rare (if true at all) you have to think out of the box. Lol.

 

[butterflyslicer]

 

[PhoebeSnow]

My close "Drop out of the Sky" came over a 2 mile lake. The Mavic stopped dead in it's tracks over the middle of the lake. The battery was ticking down the power level 45-40-35-30.....
Over the lake I was getting "Obstacle Avoidance." Say what? - I'm over a lake for heavens sake - there's nothing there. Reflection on the water caused obstacle avoidance mode. The quick answer was to disable obstacle avoidance, sport mode or even flying backwards. But as a newbie at the time I was not aware of those options and it was so new I wasn't sure where those screens were. I ended up flying farther away to get to land and without the reflection got home with 7% battery power left. After that I watched all of the videos and read as much as possible to familiarize myself with all possibilities of disasters and how to work around them.