Ocean Crash - Resolved

[HWCM]

Is this confirmed, or are you hypothesing? I haven't looked for any correlations between those issues in logs.

He is making this up. One has no effect on the other. You can fly without an SD card. I even had a corrupted SD card mid flight and it still flew fine.

 

[Cyberpower678]

I don't think dji cares about all the disconnects. it's a known problem that they are unable to solve. when I lost my mavic it was very windy and I couldn't get any missions to execute. I think the reason was, the mavic CPU's were overloaded, partly from the high wind, so they couldn't handle their workload.
so that resulted in a disconnect and/or loss of video. I think they have to add a lot more CPU power to future mavics. steve

Sorry CPU power does not correlate wind strength.

 

[Cyberpower678]

Why is this a concern?

Reading through the 'Wundertablet' thread, seems like people are using this version and 4.1.9 and are happy.

I'm due to receive my dedicated android device this week and am planning to use .15

I never said it was. I said it stood out to me.

 

[Cyberpower678]

He is making this up. One has no effect on the other. You can fly without an SD card. I even had a corrupted SD card mid flight and it still flew fine.

Not necessarily. My SD was corrupted once and my drone was a total nightmare with error messages and transmission stability. So obviously the Mavic does use the SD card for other things in addition to recording media.

 

[787steve]

Whenever I've experienced issues with the SD card, I've just stopped recording and it seems to rectify before anything bad happens. But I almost never record in 4k. I only do that in short bursts as I don't want such huge video files and I'm one of the lucky ones who hasn't had any quality issues with my camera.

Thanks for the SD comment. Good to know, and not terribly intuitive. Does the controller give you a warning with SD card problems? Newbie here. I haven't seen that yet.

 

[Cyberpower678]

Thanks for the SD comment. Good to know, and not terribly intuitive. Does the controller give you a warning with SD card problems? Newbie here. I haven't seen that yet.

The app usually does.

 

[sar104]

Hi, what software are you using to analyze this? Thanks!

On 1st January sar104 made a posting which included a detailed chart of velocity against time etc. I've been trying to locate where I would find such a chart. I have discovered "flight record" on the DJI Go 4 app, so it was useful research, but I can't find a chart. How do I find this?
Many thanks.

The data are extracted from either the onboard .DAT files or the device .txt logs using DatCon (for DAT files) or the PhantomHelp / AirData websites for basic fields from the .txt logs. For more detailed output from the .txt logs I use TXTlogToCSVtool.

Then you need a data analysis package to analyze and visualize the data; I use Wavemetrics Igor Pro, but you could equally well use MatLab or similar.

Alternatively, you can skip all that and use @BudWalker's CsvView for DAT files and .txt logs, which uses a different approach to data visualization by creating "players" but works very well.

 

[PhilBT]

The data are extracted from either the onboard .DAT files or the device .txt logs using DatCon (for DAT files) or the PhantomHelp / AirData websites for basic fields from the .txt logs. For more detailed output from the .txt logs I use TXTlogToCSVtool.

Then you need a data analysis package to analyze and visualize the data; I use Wavemetrics Igor Pro, but you could equally well use MatLab or similar.

Alternatively, you can skip all that and use @BudWalker's CsvView for DAT files and .txt logs, which uses a different approach to data visualization by creating "players" but works very well.

This is all new to me and it will take me a while to research this. Thank you very much. Really great and helpful information.

 

[ronk]

The data are extracted from either the onboard .DAT files or the device .txt logs using DatCon (for DAT files) or the PhantomHelp / AirData websites for basic fields from the .txt logs. For more detailed output from the .txt logs I use TXTlogToCSVtool.

Then you need a data analysis package to analyze and visualize the data; I use Wavemetrics Igor Pro, but you could equally well use MatLab or similar.

Alternatively, you can skip all that and use @BudWalker's CsvView for DAT files and .txt logs, which uses a different approach to data visualization by creating "players" but works very well.

That is pretty bad a s s I will start with the simpler CsvView for now. Thanks for the info!

 

[ScubaBob]

I'm afraid that DJI is correct in this case. The winds aloft were over 20 mph out of the north, as can be seen if you look at the relationship between pitch/roll and aircraft velocity:

View attachment 27797

Look, particularly, at the period from 650 s to 750 s. The aircraft heading was 328°, pointing back towards the homepoint. The aircraft was at full forwards pitch (25°) but still being pushed backwards at an average of 2 m/s. There is no way that the aircraft could have made it back against that headwind. Note that you did get multiple high wind warnings, so this should not be a surprise.

I am a scuba instructor. We always teach students that when you dive you first head INTO the current for 1/3rd of your air, then you turn around and drift back with the current to your back for 1/3rd of your air (you actually use less) and then you ascend. People who use drones need to practice the same thing. If you have the wind at your tail and use 40% of your battery going out you most likely will not get your drone back because of the head winds.

 

[Grundman83]

Hi, I'm pretty new to the Mavic, I've seen people mentioning checking winds on the "UAV app". Are you referring to the DJIgo app or is this a different app to check winds or weather patterns? Thanks.

Also, super sorry to hear about your fly-away... Is it possible that adjusting the range and altitude maximum settings would help this situation? I know the wind overpowered the Mavic but I'm wondering if a disconnection occurred if those limit settings would hold the drone within range or if those settings are disregarded in a disconnect situation?

 

[ac0j]

I am not sure why all these Mavics are flying away just because the phone app crashes.
I fly mine occasionally with NO phone or app attached. Is the remote control failing with the disconnect?

 

[sar104]

I am not sure why all these Mavics are flying away just because the phone app crashes.
I fly mine occasionally with NO phone or app attached. Is the remote control failing with the disconnect?

Most of these events are unrelated to RC or phone disconnects - they are caused by taking off from magnetically distorted locations and/or flying in winds too strong for the Mavic to reliably RTH.

 

[geigy]

Not necessarily. My SD was corrupted once and my drone was a total nightmare with error messages and transmission stability. So obviously the Mavic does use the SD card for other things in addition to recording media.

Good point. My theory goes like this:

1) The Mavic logs error messages to the SD card.
2) If that card hangs up just right, where it accepts write requests but at a reduced rate, and
3) Various threads in the Mavic's OS (the nav system, for example) happen to be generating error messages,
4) the messages pile up, waiting to be written to the SD card.
4) this impacts the Mavic's ability to process messages to and from the remote,
5) no remote messages in and/or out will cause the appearance of a disconnect.

 

[Flawless]

Most of these events are unrelated to RC or phone disconnects - they are caused by taking off from magnetically distorted locations and/or flying in winds too strong for the Mavic to reliably RTH.

Yup - too many people see the app crash/phone disconnect as a cause, when it's actually a symptom of the error causing the flyaway.

I've personally rushed my flight checklist more than once. The last time I rushed it; magnetic interference 20 seconds after takeoff, and the Mavic flew away. Turns out there was a large ferrous metal pipe right under where my Mavic was sitting when I turned it on. I hand-launched about two meters away from that spot (no errors at this point).

Immediately lost GPS lock, stopped responding to input, and drifted. I was able to get it down, and I'm thankful that it didn't cause damage (or get damaged itself).

The cost of that lesson was two props and a new pair of pants. It's not one I'll forget.

 

[geigy]

Makes Flawless sense.

 

[brichter]

So, to sum it up, when flying into a headwind there are 3 changes the pilot should make. They are, in order:

1) sport mode!
2) change altitude to see if you can find calmer air
3) "tack" left and right instead of flying straight into the wind if you can't find calmer air
4) realize tacking will take a lot more time and battery due to the increased flight time/distance

All my flights have been low altitude so far, below 30 meters, and I've only had an issue with wind one time. I landed the AC manually in an open area, and was lucky I was in a place that allowed me to do that. I'll be memorizing the above, sooner or later I'll get caught and need them. The post about 30% battery usage on the way out is good advice, too. Thanks for that, ScubaBob!

"Tacking" is the same method used by sailboats when they have to sail into a headwind, though the time/distance increase is not as critical because they're not running out of battery when they need to tack.

 

[shb]

you forgot go into sport mode

 

[brichter]

you forgot go into sport mode

Yup, thanks. Just added it.

TBH, I fly mostly in sport mode unless I'm on a mission.