GPS related crash?

[Valdez]

I would like to pick the brains of MP fliers here...

For reasons unrelated to drone flying, I have got into the habit of turning off location services on my cellphone.

On my first flight with it off, there was maybe a little less assuredness (I can't be any more specific than that) in flight performance. The second time I flew, I crashed. Damage was minimal, one badly mangled prop, the others scuffed a little. No damage to the airframe whatsoever.

Clearly, the drone hit something, but for the life of me, there was nothing to hit, it simply dropped from sixty feet onto soft grass..

My question is, if you don't use smart return home, is it still absolutely necessary to have GPS enabled on your phone (I will, anyway, now, for superstitious reasons, if nothing else)

 

[Thomas B]

GPS position is noted at every take-off by the drone itself by reading GPS satellites and that’s why it can return to home automatically if controller signal is lost.... on it’s own and land.
Turning it off in your cellphone should make no difference to the drone.

 

[sar104]

Are you just asking about whether mobile device GPS is important, or also about what caused the crash?

 

[WithTheBirds]

I would like to pick the brains of MP fliers here...

For reasons unrelated to drone flying, I have got into the habit of turning off location services on my cellphone.

On my first flight with it off, there was maybe a little less assuredness (I can't be any more specific than that) in flight performance. The second time I flew, I crashed. Damage was minimal, one badly mangled prop, the others scuffed a little. No damage to the airframe whatsoever.

Clearly, the drone hit something, but for the life of me, there was nothing to hit, it simply dropped from sixty feet onto soft grass..

My question is, if you don't use smart return home, is it still absolutely necessary to have GPS enabled on your phone (I will, anyway, now, for superstitious reasons, if nothing else)

You know it hit the ground- what makes you think it needed to hit something else?

 

[Valdez]

Are you just asking about whether mobile device GPS is important, or also about what caused the crash?

Just the mobile GPS.

I do have concern that a motor failed, or has a dodgy bearing, but there is less than 23 hours use... They all turn freely.

It is something of a mystery. I went to the site of the mishap today, there is nothing to collide with.

 

[Valdez]

You know it hit the ground- what makes you think it needed to hit something else?

I don't pretend I'm Biggles. The software carries the heavy lifting.

It was my 139th flight, all the others have been fine.

The drone had a GPS lock, and uncommanded dropped from 67ft at a maximum vertical speed of 7.2mph.

If I didn't ask it to do that, the question arises, why did it do that?

 

[JAW]

If I didn't ask it to do that, the question arises, why did it do that?

I think you'll need to get the flight logs for analysis.

 

[sar104]

Just the mobile GPS.

I do have concern that a motor failed, or has a dodgy bearing, but there is less than 23 hours use... They all turn freely.

It is something of a mystery. I went to the site of the mishap today, there is nothing to collide with.

The answer to the crash mystery will likely be in the log files, if you want to know what happened.

 

[Racin8de]

Maybe a big bird gave it a hard kicking causing it to come crashing down!

 

[Meta4]

I would like to pick the brains of MP fliers here...

It's always better to find out what actually happened rather than invite people to make guesses.
The people who can help will need to see your recorded flight data.
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.

My question is, if you don't use smart return home, is it still absolutely necessary to have GPS enabled on your phone (I will, anyway, now, for superstitious reasons, if nothing else)

Is it still necessary? It's never been necessary.
Your drone doesn't need to know where your phone is.

 

[BD0G]

Yes please upload your Flight Log so we can all see what actually happened. If there is a dodgy motor then that will show up in the flight log.

 

[Valdez]

Yes please upload your Flight Log so we can all see what actually happened. If there is a dodgy motor then that will show up in the flight log.

Hopefully, one of these files is the right one. They both refer to the crash.

I'm wondering whether the records can distinguish between a stopped motor due to failure (intermittent, or not) and a motor that stopped because the prop hit something.

Thanks, in advance for your assistance

 

[Meta4]

Hopefully, one of these files is the right one. They both refer to the crash.

I'm wondering whether the records can distinguish between a stopped motor due to failure (intermittent, or not) and a motor that stopped because the prop hit something.

Here's what that flight data looks like: DJI Flight Log Viewer - PhantomHelp.com
There's no problem with the GPS and no reason to link that to the incident.
The reason the drone came down was that at a height of 66ft at 3:53.6, you pulled the left stick down and kept it there until the drone hit the ground at 4:01.5.
The drone stayed facing 300 degrees through the descent.
It does not appear to have lost a motor as that would have induced spinning.

 

[WithTheBirds]

I don't pretend I'm Biggles. The software carries the heavy lifting.

It was my 139th flight, all the others have been fine.

WThe drone had a GPS lock, and uncommanded dropped from 67ft at a maximum vertical speed of 7.2mph.

If I didn't ask it to do that, the question arises, why did it do that?

Maximum descent of 7mph (in round figures) accords well with being flown into the ground. Seems to be the case based on the flight data. Mystery solved.

 

[BD0G]

This is odd as even the most inexperienced pilots wont pull the left stick down and hold it there if they have VLOS and see the Mavic descending right into terrafirma. They typically take corrective action before it goes boom.
Perhaps a stuck stick on the remote controller or some malfunction of the remote control?

 

[InvisibleName]

This is odd as even the most inexperienced pilots wont pull the left stick down and hold it there if they have VLOS and see the Mavic descending right into terrafirma. They typically take corrective action before it goes boom.
Perhaps a stuck stick on the remote controller or some malfunction of the remote control?

Agreed, unless they got confused & were desperately trying to gain height but we’re pushing the stick in the wrong direction

 

[BD0G]

True. Panic induced stick movement. I did some of that when first starting out. I figured out though that best thing to do when one can feel that sense of panic is to just stop all stick movements and think what is the best maneuver in the given situation.

 

[DanMan32]

I agree 100%.
My P3 once flipped out, started banking. I thought it was a gimbal problem at first. A few seconds later got compass error and kicked into Atti mode but stopped banking.
OK, it's high enough, and drifting in the wind. Take deep breath and start steering it home.
Within less than a minute the problem cleared up and went back to P mode.

If I had panicked, I could have made the problem critical.

 

[Valdez]

Here's what that flight data looks like: DJI Flight Log Viewer - PhantomHelp.com
There's no problem with the GPS and no reason to link that to the incident.
The reason the drone came down was that at a height of 66ft at 3:53.6, you pulled the left stick down and kept it there until the drone hit the ground at 4:01.5.
The drone stayed facing 300 degrees through the descent.
It does not appear to have lost a motor as that would have induced spinning.

Thanks a lot...

I don't remember pulling the left stick

This is odd as even the most inexperienced pilots wont pull the left stick down and hold it there if they have VLOS and see the Mavic descending right into terrafirma. They typically take corrective action before it goes boom.
Perhaps a stuck stick on the remote controller or some malfunction of the remote control?

OK, I'll admit, it was poor flying, and shortly after taking off, I regretted it. I rarely use the RTH button, but was contemplating it, at the time of the crash.

True. Panic induced stick movement. I did some of that when first starting out. I figured out though that best thing to do when one can feel that sense of panic is to just stop all stick movements and think what is the best maneuver in the given situation.

If I may interject here, as I recall, I regretted taking off, after realising that the landscape I had hoped to photograph, was utterly black, and unlit (night flight, in the morning the early hours, in the middle of nowhere), but the landing was going to be tricky.

I'd brought it closer and down, and was contemplating RTH when it became obvious it wasn't airborne anymore.

I fully accept it was poor flying, I admit I'd lost sight of it, even relatively close, I'm just glad that a) it was hardly damaged, and b) I don't have mechanical issues with the motors.

I struggle to believe I held the left stick down, and explain this by the fact that it is 30C here, at night, while my drone and controller are 10 degrees lower, spending their non flying time in a temperature controlled room. I suspect condensation played its part, in making undesirous electrical contact. That's my story, and I'm sticking to it

 

[Meta4]

I struggle to believe I held the left stick down, and explain this by the fact that it is 30C here, at night, while my drone and controller are 10 degrees lower, spending their non flying time in a temperature controlled room. I suspect condensation played its part, in making undesirous electrical contact.

Here's the data from the last 8 seconds.
Each yellow square in the throttle column has the number 364 which indicates the left stick in the full back position.
The mauve line marks the crash into the ground.