WTF happened here?

This was scary. Only a few flights with my new Mavic Zoom and was just having a short flight at the back of the house the other day.

I hit RTH, because I wanted to see what route it would take and then cancelled it, only to find it had lost connection! Looking at the log, there is nothing between 390ft and 7ft. Also there seems to be a 2 minute gap.

It did hover, but was slowly coming down into the vegetable garden, where there are lots of sticks, canes etc! No response from sticks so I switched the controller off and on again and , thankfully it re-connected and I was able to land safely.

Phew!!! It has really knocked my confidence, especially after losing the last one and because I often fly over water.

2 things. Why!!! and did I do the right thing in re-booting the controller?

Here’s the log.
DJIFlightRecord_2019-09-30_[09-35-44].txt (464.4 KB)

Difficult to tell “what happened” …. since there is absolutely no data in the log file for that time.

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And there’s nothing strange before that point to give any indication.

The DAT from the M2Z might provide more info.

(Although something happened on my MP a few months back and the first part of the flight data was totally missing from the DAT. :man_shrugging:)

Totally irrelevant to that issue, subsequent to regaining connection I did see it was complaining about the SD Card being too slow for 4k vid.

As far as I’m aware no one has created a workaround for the encryption yet on the Mavic 2.

I thought that had now been solved.

You might be correct.

Last time I checked CSView and Datcon did not support it but was few months ago.

Hmmm - indeed - nothing about M2P/M2Z in the release notes.

Just curious, how far were you from the home point in horizontal and vertical distance when you pressed RTH?

What colour was the LED?

Did you press and hold the RTH until it’s confirmation beep when you cancelled?

Did you read the manual?

Distance from home 930ft (283m), altitude 390.7ft (119m)

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I’m afraid I didn’t notice the colour of the LED.

Yes I did press & hold the RTH and it did RTH, but I’m not sure at what point it lost signal. It is set to RTH on signal loss so it could’ve been anywhere between the farthest and the nearest point. My guess is, from the log that it lost signal when 1ft horizontal and 390ft vertical.

Yes, I spend quite a lot of time reading the manual. In bed usually ! :grinning:

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That clears my question, I asked because RTH behaviour is a little different when close in within 20 meters and at low altitudes 5 meters.

It did perform the RTH completely OK. Flew to overhead and descended to about 2m before it lost connection.

I know. The only fast card I have is at the bottom of the Forth Estuary. :crazy_face: I’ve ordered another but it hasn’t arrived yet.

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H and I - RTH initiated
J - Overhead - Autoland initiated
L - @ 2.3m when link reconnected

You’re right Dave. Actually I think I raised up to 8 ft before it lost connection. However, I was under the impression that I had cancelled RTH but no mention of that.

The only thing I can say is that there are some power lines about 30m away, although not high voltage, just 440V 3 phase. I wouldn’t have thought that would affect transmission though.

I’ve flown close to high voltage pylons/cables … and (@joe.k) flew between cables (in a Litchi mission) …. all without any noticeable issue.

Edit: Actually, one of my test flying fields (before it was zapped by runway line extensions to FRZs) has massive ones. :wink: )

Why is the Data Loss reported as 76.7 seconds, yet the time gap between events is over 2 minutes?

Because that lost only shows when there are events to report. There was nothing to report during the descent.

Yes, I’ve never been worried by it. I don’t think the data transmission frequency would appear in the electrical spectrum, maybe only a very feint harmonic, if anything.

The actual gap in the data - in milliseconds

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