Welcome Mavic Pilot!
Jump in and join our free DJI Mavic community today!
Sign up

Not quite sure where I went wrong

fowleronline

New Member
Joined
Jul 1, 2018
Messages
4
Reaction score
0
Age
57
Hi, I've had my Mavic Air for a couple of months now and had my first crash yesterday. I've flown it quite a bit, but I am no expert and I'm now doing my "Air Crash Investigator" thing... black box was recovered!

Problem? crashed into the sea

Was unit in a crash? more of a plop...

What have you tried so far? still drying it out, not tried it yet.

What device are you using ( iphone , ipad, Samsung , etc)? Samsung s7

What firmware are you running ( aircraft, remote controller)? Latest version

What Go app version are you using? v4 - latest

Any modification?
(if so what) no

Did you change anything or install any apps? (if so what) no

Do you have a video or pictures of the problem? (if so post link) no


If I have done this right, the log is here... DJI Flight Log Viewer - PhantomHelp.com
if not it should be attached to this thread.

OTHER INFO.
The flight was in the UK on a beach where I have flown many times. Take off was literally 1ft above sea level. It's very gently sloping beach. I had taken a couple of pictures back towards the beach where my family was, and decided I wanted to be in closer.



I hope this works...


I was about 10' above the surface and wanted to be about 5'. There was a 5mph steady wind and it was not a problem. Bright sunlight at about 10am, tide coming in, virtually no swell. Total flight 33 seconds. Wend down in knee deep water so about 18" off the sand.
The text log I uploaded and the log in the DJI4 app show different heights. The app shows stick instructions, but I can't see them on the log, is there something else I need to look at/upload?

Thanks in advance for your advice.
 

Attachments

msinger

DJI Drone Expert
Approved Vendor
Premium Pilot
Joined
Oct 12, 2016
Messages
20,928
Reaction score
11,318
Location
Harrisburg, PA (US)
The app shows stick instructions, but I can't see them on the log, is there something else I need to look at/upload?
You can see the stick positions (columns AG - AK) in the CSV file that's attached to the log you linked above. Your log shows you held the throttle in the full down position until your Mavic crashed into the surface of the water.

Log.jpg
 

fowleronline

New Member
Joined
Jul 1, 2018
Messages
4
Reaction score
0
Age
57
Thanks, I remember "blipping" the down to drop those few feet as I flew in but it felt like it just flew into the surface. I cannot see the columns you show on my computer, I only get...
Time Flight Mode GPS IMU
Altitude
VPS
Altitude
Speed Home
Distance
Battery Battery
Voltage
Cell 1 Cell 2 Cell 3 Cell
Deviation
Message
where do I find the others please? I don't remember any proximity warning either, does it show that please? I don't know if there is further telemetry that I cannot see (though I would probably not understand it if I did).
Thanks again.
 

sar104

Dic mihi solum facta, domina.
Premium Pilot
Joined
May 27, 2017
Messages
8,474
Reaction score
9,303
Location
Los Alamos, NM
Thanks, I remember "blipping" the down to drop those few feet as I flew in but it felt like it just flew into the surface. I cannot see the columns you show on my computer, I only get...
Time Flight Mode GPS IMU
Altitude
VPS
Altitude
Speed Home
Distance
Battery Battery
Voltage
Cell 1 Cell 2 Cell 3 Cell
Deviation
Message
where do I find the others please? I don't remember any proximity warning either, does it show that please? I don't know if there is further telemetry that I cannot see (though I would probably not understand it if I did).
Thanks again.
It looks like it continued to descend after you released the throttle, but only for 0.5 s or so. I think that you were expecting too much to be able to use that level of precision and timing working within a meter or so of the water.

2018-07-01_[10-43-20]_01.png
 

msinger

DJI Drone Expert
Approved Vendor
Premium Pilot
Joined
Oct 12, 2016
Messages
20,928
Reaction score
11,318
Location
Harrisburg, PA (US)

fowleronline

New Member
Joined
Jul 1, 2018
Messages
4
Reaction score
0
Age
57
Thanks again, I did not realise the CSV file was different to the log file, I thought it was just a different format.
I'm sure this will have been my fault, but I am trying to understand why, having done this manoeuver many time photographing my dogs., it should have gone wrong this time.
Any thoughts on the collision avoidance warning - I can't see anything? I don't remember an alert, would this be on the log?
On the log, It only looked as if I down throttled for half a second, am I reading it wrong? That close to the ground I usually hear something, it shouldn't plough into the ground. Is it reading the heights correctly, I cannot find that.
Sorry for all the questions, I'm sure I will read these sheets better with practice.
Thanks.
 

sar104

Dic mihi solum facta, domina.
Premium Pilot
Joined
May 27, 2017
Messages
8,474
Reaction score
9,303
Location
Los Alamos, NM
Thanks again, I did not realise the CSV file was different to the log file, I thought it was just a different format.
I'm sure this will have been my fault, but I am trying to understand why, having done this manoeuver many time photographing my dogs., it should have gone wrong this time.
Any thoughts on the collision avoidance warning - I can't see anything? I don't remember an alert, would this be on the log?
On the log, It only looked as if I down throttled for half a second, am I reading it wrong? That close to the ground I usually hear something, it shouldn't plough into the ground. Is it reading the heights correctly, I cannot find that.
Sorry for all the questions, I'm sure I will read these sheets better with practice.
Thanks.
I would not trust the downward sensors over water.
 

Mossiback

Well-Known Member
Joined
Oct 3, 2017
Messages
3,675
Reaction score
2,651
Age
65
Location
Brier, WA USA
...That close to the ground I usually hear something, it shouldn't plough into the ground. Is it reading the heights correctly, I cannot find that...
The downward sensors can have difficulty detecting water so they cannot be relied on to stop your decent.
 

fowleronline

New Member
Joined
Jul 1, 2018
Messages
4
Reaction score
0
Age
57
Thanks, I was not relying on it, I just don't remember it doing any warning even though it was registering a low height on the log. Anyway... It's had 48 hours drying after a good wash and... it's dead, and obviously the battery too.
Time to find a service centre and see how bad DJI support really is (allegedly).

Well... I will try to learn from my mistakes, one of many I have no doubt.

Thanks again.
 

Mossiback

Well-Known Member
Joined
Oct 3, 2017
Messages
3,675
Reaction score
2,651
Age
65
Location
Brier, WA USA
Thanks, I was not relying on it, I just don't remember it doing any warning even though it was registering a low height on the log. Anyway... It's had 48 hours drying after a good wash and... it's dead, and obviously the battery too.
Time to find a service centre and see how bad DJI support really is (allegedly)...
There is no low height warning. You can launch from a hilltop and fly down and Go 4 will show your height in negative numbers. If landing precision is turned on it may stop the decent and give you an area unsuitable for landing message, but this may not work over water.

I am sorry for your loss. I had a "mishap" and got my replacement from CA in 10 days.
 

Thwyllo

Well-Known Member
Joined
Mar 27, 2018
Messages
656
Reaction score
322
Age
65
Location
Hautes Pyrenees, SW France
Thanks again, I did not realise the CSV file was different to the log file, I thought it was just a different format.
A CSV file isn't a proprietary DJI file, it's just an industry standard raw data file that can be recognised by, and pasted into, pretty much any spreadsheet application (and a few other things besides). I don't know what data it holds in this case but normally it would be pretty much everything unless there are multiple CSV files for different areas of telemetry.
 

Douganator

Member
Joined
Mar 15, 2018
Messages
9
Reaction score
0
Age
41
If landing precision is turned on it may stop the decent and give you an area unsuitable for landing message, but this may not work over water.
This actually saved me the first time I flew over the ocean. I pressed the auto landing button instead of return to home and was waiting to see the drone come towards me. Looked down at the screen and bugger me, unsuitable for warning Hahahahaa.
 

UAVNV

Well-Known Member
Joined
Jul 19, 2017
Messages
235
Reaction score
146
Age
42
It happens, If you do fly again give the manual a good read,
its said a thousand times I know, always the number one culprit of pilot error it seems.