Toilet Bowl Effect- Mavic Pro

SoCalDude · Jan 20, 2019

I wonder if the Kp-Index at that time had anything to do with the GPS and dropping into ATTI mode.

Meta4 · Jan 20, 2019

SoCalDude said:
I wonder if the Kp-Index at that time had anything to do with the GPS and dropping into ATTI mode.

The KP index has never had anything to do with any DJI drone flying incident.

sar104 · Jan 20, 2019

The exact cause of the problem isn't clear, but the IMU ended up with a completely incorrect yaw value:

sar104 · Jan 20, 2019

SoCalDude said:
I wonder if the Kp-Index at that time had anything to do with the GPS and dropping into ATTI mode.

The ATTI mode was not due to GPS issues, as I pointed out in post #13.

BrucenYvette · Jan 20, 2019

Hmmmmm! Then it seems that there should be a bunch more data on that .DAT file than 5 flight records, yes? Is there a way to "explore" that internal sd?

BrucenYvette · Jan 20, 2019

Just looked at the GPS / IMU track. The two tracks are parallel until the RTH brought the bird directly overhead the home-point. Then he GPS track is the actual flight path of the rogue drone while the IMU looks like it caught a connecting flight to someplace else LOL!! Wat up with that?

BudWalker · Jan 21, 2019

BrucenYvette said:
Well, guys, looks like I've come to a "dead-end". I'm not able to retrieve the .DAT data file. Not sure why not, but that flight data from December is "wiped". I'm guessing that it's because last week I downgraded my firmware because of DJI's latest "No Fly Zone" changes in their firmware.

I mentioned in the beginning of my post that I've only been flying since June. At the same time that I've been over-the-top happy with the Mavic Pro "bird", my displeasure with DJI Go 4 and their firmware updates has grown exponentially! It seemed like every time I got comfortable with the bird and the App, DJI came along and changed something. Twice caused me not just anguish, but 2 crashes as well.

I finally "quit" DJI Go 4 and started flying Litchi exclusively AND pretty much glitch-free!! Two weeks ago, DJI messed that up when they modified their NFZ settings and I found myself unable to fly one of my favorite places- even with Litchi- because the location was just at the 5-mile edge of a local airport! DJI was "nice-enough" to "accommodate" me by giving me "permission" to fly at my favorite location AS LONG AS I LOGGED ON TO A SPECIAL WEBSITE WHERE THEY WOULD GIVE ME 3 DAYS PERMISSION!! Well, I said to myself, "Self, screw this BS!"

I did a bunch of research and came across NoLimitDronz. Now I can fly Litchi or I can fly an NLD-patched version of DJI Go 4. So, I'm guessing that my firmware downgrade from V01.04.0400 to V01.04.0300 erased my December flight data. Or, perhaps, the fact that I've been flying Litchi 100% since back in October is the issue. Don't know...but currently I'm only showing a flight index of my most recent 5 flights flown by the patched DJI Go app.

So, can you give any theories about what happened on flight you've examined?

You're right. The downgrade from V01.04.0400 to V01.04.0300 has caused the .DAT file to not be accessible. The .DAT wasn't erased, it was just never recorded. See this thread.
Keeping .DATs on the Mavic Pro accessible
That's unfortunate. This incident is unlike any I've seen and the .DAT would've helped to see what happened.

I suspect the incident started at about 960 secs when the the MP was in ATTI mode and then commanded to GoHome. It was still in ATTI mode. Navigating the straight line back to the vicinity of the home point was easy enough. But, then attempting to perform the precise corrections necessary to hover over the HP caused the TBE. Just a theory - could be total nonsense. But, it's all I have.

BTW, my question about why you thought the MP lost GPS lock was intended to see if the Litchi app had said something about GPS. Unfortunately, the Litchi app doesn't record a lot of data that's useful for incident analysis. In particular, it doesn't record gpsHealth (aka gpsLevel or navHealth) or nonGPS Cause.

sar104 · Jan 21, 2019

BudWalker said:
You're right. The downgrade from V01.04.0400 to V01.04.0300 has caused the .DAT file to not be accessible. The .DAT wasn't erased, it was just never recorded. See this thread.
Keeping .DATs on the Mavic Pro accessible
That's unfortunate. This incident is unlike any I've seen and the .DAT would've helped to see what happened.

I suspect the incident started at about 960 secs when the the MP was in ATTI mode and then commanded to GoHome. It was still in ATTI mode. Navigating the straight line back to the vicinity of the home point was easy enough. But, then attempting to perform the precise corrections necessary to hover over the HP caused the TBE. Just a theory - could be total nonsense. But, it's all I have.

BTW, my question about why you thought the MP lost GPS lock was intended to see if the Litchi app had said something about GPS. Unfortunately, the Litchi app doesn't record a lot of data that's useful for incident analysis. In particular, it doesn't record gpsHealth (aka gpsLevel or navHealth) or nonGPS Cause.

The Litchi CSV file doesn't include those data, but Litchi also writes a standard txt log to the Litchi/Documents/SDK_logs/FlightRecord directory on the mobile device, which does have OSD.gpsLevel, OSD.compassError and OSD.nonGPSCause.

BrucenYvette · Jan 21, 2019

Here is the Litchi CSV file for that flight. Apparently, Forum doesn't accept CSV attachment. I converted to TXT. Any use? BTW, thanks again for the time and effort at unraveling this puzzlement... Thumbswayup

sar104 · Jan 21, 2019

BrucenYvette said:
Here is the Litchi CSV file for that flight. Apparently, Forum doesn't accept CSV attachment. I converted to TXT. Any use? BTW, thanks again for the time and effort at unraveling this puzzlement...

You already supplied that file via AirData - it's the one that we have been working from. It's the txt log that has some extra data - see post #28 above.