Please select Into the mobile phone version | Continue to access the computer ver.
Ocean Crash (Need help confirming data)
1465 12 2017-10-9
Uploading and Loding Picture ...(0/1)
o(^-^)o
HittmanA
lvl.1
Flight distance : 163835 ft
Canada
Offline

I have read though several crash/lost threads and have learned that there are many on here who can look at log data to confirm what happened in a crash/loss situation. I have uploaded my log to: http://www.phantomhelp.com/LogViewer/RU44ONDPM5YTNDXG82L8/. If anyone could take a look and let me know there thoughts it would be greatly appreciated.
2017-10-9
Use props
RedHotPoker
Captain
Flight distance : 165105 ft
Canada
Offline

You started this mission, with your flight Battery at 45%?

Why'd ya do?, she said...


RedHotPoker
2017-10-9
Use props
HittmanA
lvl.1
Flight distance : 163835 ft
Canada
Offline

Yeah hindsight is always 20/20. After a few hours of nothing interesting I finally found sealife (dolphins, I am pretty sure but could have been sharks), first battery died (got the drone back no problem), and wanted to get more shots so I put the second battery in on less than half charge hoping to get some more time with them. It was going just fine till it was'nt. The battery seem fine then seemed to discharge rapidly, then gave out with 7% or so and did not make it back to the beach.
2017-10-9
Use props
RedHotPoker
Captain
Flight distance : 165105 ft
Canada
Offline

HittmanA Posted at 2017-10-9 11:48
Yeah hindsight is always 20/20. After a few hours of nothing interesting I finally found sealife (dolphins, I am pretty sure but could have been sharks), first battery died (got the drone back no problem), and wanted to get more shots so I put the second battery in on less than half charge hoping to get some more time with them. It was going just fine till it was'nt. The battery seem fine then seemed to discharge rapidly, then gave out with 7% or so and did not make it back to the beach.

It's a known issue, that using a partially depleted battery can result in errors of the expected remaining voltage.
I'm very sorry that you had to be one of the unluckiest SOB's to experience this bummer. What a drag.


Are you a good swimmer? At least you could dive in there and enjoy the water. ;-)

When you replace that drone, you will be all the wiser. Flying over deep & open water is often a bad idea.

Some if the most incredible videos, are filmed, while flying over water....

RedHotPoker
2017-10-9
Use props
DJI-Mark
First Officer

United States
Offline

Flying over the ocean presents it's own problems. You always need to start off with the batteries at 100 percent. Sorry on your crash.
2017-10-9
Use props
ALABAMA
Captain
Flight distance : 10442687 ft
United States
Offline

Yet another case of running battery completely out  
2017-10-9
Use props
Genghis9
Captain
Flight distance : 961 ft
United States
Offline

Concur, you ran out of juice, UAV then pretty much dropped out of the sky...
Curious, you were in auto land for just about 42 seconds, as soon as the bird went in to auto land you began loosing altitude slowly and then jammed on the throttle (which didn't help the battery drain) so you had to know you were in trouble.  You were nearly out 2600 feet and about half again as much from shore with only 10% battery, did you ever get a low battery warning first?  If you had headed directly for shore you might have made landfall, and maybe saved your aircraft, depending on how far down it fell of course.
Yes let me repeat/pile on
Do not take off with less than a full battery and mind your power levels always...

I'm amazed you got 19 and a half minutes out of a 45% battery.
2017-10-9
Use props
Labroides
Captain
Flight distance : 9991457 ft
  • >>>
Australia
Offline

Your flight record doesn't show a steep drop in battery level that is usual with a battery that has been sitting around discharging.
Also the flight record starts at 11 mins so it looks like the battery had only been recently flown.
The battery appears to be working normally and was not the problem.
Although it is very important to only fly with a fully charged battery, that is not the cause of your problem so you can ignore those comments here.

The problem was that you kept flying and flying until the battery got to its critically low level (10%) which triggers autolanding.
At the time you were 2600 feet offshore and the rest is obvious.
Flying anywhere you should have your Phantom back and landed well before it gets to critically low level.
And for flying at sea, you need a bigger safety margin to deal with unexpected events.
Flying at sea is great but it's an unforgiving environment.
One mistake out there can easily be the last.
2017-10-9
Use props
Labroides
Captain
Flight distance : 9991457 ft
  • >>>
Australia
Offline

Genghis9 Posted at 2017-10-9 14:33
Concur, you ran out of juice UAV then pretty much dropped out of the sky...
Curious, you were in auto land for just about 42 seconds, as soon as the bird went in to auto land you began loosing altitude slowly and then jammed on the throttle (which didn't help the battery drain) so you had to know you were in trouble.  You were nearly out 2600 feet and about half again as much from shore with only 10% battery, did you ever get a low battery warning first?  If you had headed directly for shore you might have made landfall, and maybe saved your aircraft, depending on how far down it fell of course.
Yes let me repeat/pile on

I'm amazed you got 19 and a half minutes out of a 45% battery.

That would be amazing, but he only squeezed a little more than 8 minutes out of it.
2017-10-9
Use props
Genghis9
Captain
Flight distance : 961 ft
United States
Offline

Labroides Posted at 2017-10-9 17:56
I'm amazed you got 19 and a half minutes out of a 45% battery.

That would be amazing, but he only squeezed a little more than 8 minutes out of it.

Ah!
I see my mistake, thanks for pointing that out.
So, now I have to know.  How can a flight/new battery start at 11 minutes 1.1 seconds records wise?  
I have swapped out batteries and the thing zeros out, I assume because I had to shut down and the battery was powered off.  Why did it start off at that time line?
Thanks
2017-10-9
Use props
Labroides
Captain
Flight distance : 9991457 ft
  • >>>
Australia
Offline

Genghis9 Posted at 2017-10-9 18:04
Ah!
I see my mistake, thanks for pointing that out.
So, now I have to know.  How can a flight/new battery start at 11 minutes 1.1 seconds records wise?  

Usually it means someone has done a touch and go or the flight record has been interrupted.
The steady, slow drain on the battery suggests that it was acting like a fresh battery that had just been run down to 45% shortly before.
2017-10-9
Use props
Genghis9
Captain
Flight distance : 961 ft
United States
Offline

Labroides Posted at 2017-10-9 18:25
Usually it means someone has done a touch and go or the flight record has been interrupted.
The steady, slow drain on the battery suggests that it was acting like a fresh battery that had just been run down to 45% shortly before.

Yes, I fully understand your analysis of the second part.
However, it's the first part that I don't get.  My definition of a T&G is land and either take off again or land and shutdown rotors but do not power down battery then restart motors and take off again.
Yet in this case he clearly stated he pulled a battery and inserted this 45% one, which means it had to be powered down before input.  Then powering on I'd think it would reset like any other start up.  In this case it did not and that baffles me?
2017-10-9
Use props
endotherm
Captain
Flight distance : 503241 ft

Australia
Offline

This shows a normal flight, but the pilot clearly did not notice the warnings on the screen until it was too late.

To clarify, you can get away with using a "just-flown" battery, where the remaining capacity estimations are still fairly accurate.  That does not apply to a "yesterday-battery" or a "last-week" battery.  So the advice of always trying to use a 100% charged battery is valid, but it did not have an effect on the outcome of this flight.

At 10% when the aircraft commenced a critical battery landing, we see the pilot maintain a full forward stick command for the remaider of the flight.  As the aircraft descended, the pilot seems to have noticed the loss of altitude and pushed up on the stick to climb.  This gained altitude, but the stick was again released, resuming the landing/descent.  It is completely permissible (and recommended!) to override the height in circumstances such as these.  Had the pilot maintained sufficient altitude by applying a constant climb command (say 50%), it is highly likely that the aircraft could have been flown manually to the beach and saved.  It would only have required sufficient stick input to maintain the altitude, not climb at maximum rate and exhaust the battery quicker.  It would still have had maybe a couple of minutes of flight before a critical battery shutdown.  Eventually the battery will become so low that it becomes imperative to land, and the software will not respond to any further override commands to keep it in the air.  There was literally only 600 feet to the beach in this instance.  That's about 20 seconds at full speed, easily within the 10% remaining capacity.  In this case the aircraft was lost because the aircraft was left to follow its auto-landing state, and only periodically instructed to gain altitude.  The battery "gave out" at 7% because that is when the impact with water occurred.

One weird aspect of this flight record was that the column for GoHomeStatus showed it was in "Cruise" mode for the whole flight.  I haven't seen that in a P3P record before.

I have seen other flight records where the time does not start from 0, but I haven't determined why this is.  In this case it indicates that the flight timer had started and was running 661 seconds earlier.  It is unknown how a battery change affects this.  It may require a "break" in the app to reset the clock.
2017-10-10
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules