Loss of connection.....loss of drone

hewo · May 16, 2019

How could sar be ineligible if qualified? What prereq is deficient for presidency?

Maviac · May 16, 2019

Dark Horse said:
I think Sar104 deserve a bottle of what he likes to drink ???‍Lol.

Seriously. That's Macallan 18-level advice.

sar104 · May 16, 2019

hewo said:
How could sar be ineligible if qualified? What prereq is deficient for presidency?

What 45 alleged 44 was deficient on.

hewo · May 18, 2019

sar104 said:
What 45 alleged 44 was deficient on.

Should be based on years of flying, weighted by factors pertinent in flying that represent (quantifies) level of knowledge, skills and abilities

pjd900 · May 22, 2019

Nakita Mosquita said:
I am very pleased with the outcome working with DJI. Must acknowledge the experience of Sar and his help interpreting the event log. DJI initially offered a 30% reduction but reviewed my case again and examined the Event stream and concluded they would replace my MA free with a new battery and props. Once the determination had been made, the replacement was sent out within 1 day UPS out of California. Now the excitement of receiving new bird. My experience with DJI has been great with regular and prompt email replies and quick communication re the status of my case. Will spend time testing and understanding RTH features. Excitement of finding out they would replace nicely offset the feeling of loss of my MA.

Hi Nakita...how did you go about getting DJI to take another look at (escalate) your case?

I’ve gone back and forth with my DJI “data analyst” via email with no result. They’re only offering the 30% off a new Mav 2 Pro. It’s very frustrating because it takes 24-36hrs to receive a response, and they never really answer my questions.
Thanks!

Nakita Mosquita · May 22, 2019

pjd900 said:
Hi Nakita...how did you go about getting DJI to take another look at (escalate) your case?

I’ve gone back and forth with my DJI “data analyst” via email with no result. They’re only offering the 30% off a new Mav 2 Pro. It’s very frustrating because it takes 24-36hrs to receive a response, and they never really answer my questions.
Thanks!

Hi there...yes...the tech folks communication via e-mail, an initial offering of 30% off....My math showed that this offer sucked when I determined the actual amount I was going to be expected to pay for just the drone and a battery and shipping. For a few hundred dollars more, I could have purchased a brand new unit. I simply asked that my case be reviewed looking at the Event Data Stream and asked to be in contact with a supervisor. Quite shortly (maybe a day or 2) I received a phone call from EJay in China (huge time difference). We spoke twice (a day apart) and on the 3rd day, I received an e-mail requesting my address etc and that they were replacing my unit free. I have to believe the Event Stream (not the data log) clearly indicated a malfunction. It appears that DJI is not in the practice of replacing for free. I did not buy the added protection. Best of luck.

sar104 · May 22, 2019

Nakita Mosquita said:
Hi there...yes...the tech folks communication via e-mail, an initial offering of 30% off....My math showed that this offer sucked when I determined the actual amount I was going to be expected to pay for just the drone and a battery and shipping. For a few hundred dollars more, I could have purchased a brand new unit. I simply asked that my case be reviewed looking at the Event Data Stream and asked to be in contact with a supervisor. Quite shortly (maybe a day or 2) I received a phone call from EJay in China (huge time difference). We spoke twice (a day apart) and on the 3rd day, I received an e-mail requesting my address etc and that they were replacing my unit free. I have to believe the Event Stream (not the data log) clearly indicated a malfunction. It appears that DJI is not in the practice of replacing for free. I did not buy the added protection. Best of luck.

Just to clarify - it appears that the initial assessment by DJI is fairly basic - a quick, probably automated look at the telemetry to see if there is anything obvious. From several different cases it's apparent that once the relevant event stream entries are pointed out to them they do come to the correct conclusion. That's also true of other kinds of evidence - for example in a couple of cases I've pointed to clear disagreement between the two IMUs, as recorded in the DAT file, and they have revised their conclusion to hardware failure. In fact I don't recall any cases where they ignored such evidence.

Nakita Mosquita · May 22, 2019

sar104 said:
Just to clarify - it appears that the initial assessment by DJI is fairly basic - a quick, probably automated look at the telemetry to see if there is anything obvious. From several different cases it's apparent that once the relevant event stream entries are pointed out to them they do come to the correct conclusion. That's also true of other kinds of evidence - for example in a couple of cases I've pointed to clear disagreement between the two IMUs, as recorded in the DAT file, and they have revised their conclusion to hardware failure. In fact I don't recall any cases where they ignored such evidence.

Your insight and experience makes you an invaluable helper. Thanks for sharing.

windluv · Jun 2, 2019

Hello gentlemen,

@sar104 came with a recommendation from @DoomMeister in the Yuneec forums which I have been associated with for a long time.

Same issue, flying the Mavic 2 Pro for third time, did not come home. First time in a location which I have flown at for the past year with the Yuneec Typhoon H Pro and H Plus. Been flying up and down this area of beaches and oceans north of Santa Cruz Ca, for about 7 years. Never had a drone issue; they have always come back. I sold the Typhoon H Plus (C23 1" camera) to get the Mavic 2 Pro; principally for the Occusync 2 to visualize the flight with excellent clarity as I fly mainly FPV.

I have already submitted the case to DJI. I have the DJI Care. They have assessed against me, as I cannot retrieve the drone from dangerous waters. 15% discount is their final offer after a couple of rounds of asking for them to reassess.

I don't want to give a lot of details on the flight initially as to not color any data assessment this forum may contribute. I am open to any question afterwards. But in essence the controller showed a disconnect suddenly and RTH did not work.

Final moment summary : I initiated a slow turn back to my heading at about 12 minutes of flight. I was flying at about 18' of altitude, which is actually high for me. I do fly low; the first portion of the flight was at that altitude, then dipping to 4' and then coming back up to 20' to return home. I saw a sea-otter in the awesome Occusync 2 video stream and initiated an elevator slow down to hover. At that very point lost connection. Immediately hit a throttle up to get altitude; still no connection. Then hit RTH. Waited for many minutes for the drone to appear or a connection. Feels like being punched in the stomach during hi-school in front of friends.

I am attaching the .dat file for this flight. The flight replay in the Go4 app showed GPS at 18' at the very end which is consistent with the actual view I had. Video apparently did not record as the video cache was full; this is a novice mistake that I did make.

I am looking for honest assessment to see if it confirms what DJI is stating. I will upload the email exchange between us when requested.

I thank you all,

Thomas

sar104 · Jun 2, 2019

windluv said:
Hello gentlemen,

@sar104 came with a recommendation from @DoomMeister in the Yuneec forums which I have been associated with for a long time.

Same issue, flying the Mavic 2 Pro for third time, did not come home. First time in a location which I have flown at for the past year with the Yuneec Typhoon H Pro and H Plus. Been flying up and down this area of beaches and oceans north of Santa Cruz Ca, for about 7 years. Never had a drone issue; they have always come back. I sold the Typhoon H Plus (C23 1" camera) to get the Mavic 2 Pro; principally for the Occusync 2 to visualize the flight with excellent clarity as I fly mainly FPV.

I have already submitted the case to DJI. I have the DJI Care. They have assessed against me, as I cannot retrieve the drone from dangerous waters. 15% discount is their final offer after a couple of rounds of asking for them to reassess.

I don't want to give a lot of details on the flight initially as to not color any data assessment this forum may contribute. I am open to any question afterwards. But in essence the controller showed a disconnect suddenly and RTH did not work.

Final moment summary : I initiated a slow turn back to my heading at about 12 minutes of flight. I was flying at about 18' of altitude, which is actually high for me. I do fly low; the first portion of the flight was at that altitude, then dipping to 4' and then coming back up to 20' to return home. I saw a sea-otter in the awesome Occusync 2 video stream and initiated an elevator slow down to hover. At that very point lost connection. Immediately hit a throttle up to get altitude; still no connection. Then hit RTH. Waited for many minutes for the drone to appear or a connection. Feels like being punched in the stomach during hi-school in front of friends.

I am attaching the .dat file for this flight. The flight replay in the Go4 app showed GPS at 18' at the very end which is consistent with the actual view I had. Video apparently did not record as the video cache was full; this is a novice mistake that I did make.

I am looking for honest assessment to see if it confirms what DJI is stating. I will upload the email exchange between us when requested.

I thank you all,

Thomas

You were flying very low at the end of that flight - nowhere near 20 ft:

At the end of the record the accelerometer, rate gyro, magnetometer and motor speed data are all consistent, and suggest that you flew it into something on the left side of the aircraft - most likely a wave I would guess:

The left side motors were impeded and the aircraft was briefly kicked up and right, yawing CW. Then the log ends.

pjd900 · Jun 2, 2019

sar104 said:
You were flying very low at the end of that flight - nowhere near 20 ft:

View attachment 74297

At the end of the record the accelerometer, rate gyro, magnetometer and motor speed data are all consistent, and suggest that you flew it into something on the left side of the aircraft - most likely a wave I would guess:

View attachment 74298

View attachment 74299

View attachment 74300

The left side motors were impeded and the aircraft was briefly kicked up and right, yawing CW. Then the log ends.

I haven’t performed a search yet, but I’m wondering what the live video latency is with the Mavic 2 Pro.
I surmise that, with a 1-2 second video delay, while attempting to fly in close proximity to to immovable objects...quick reactions by the operator to avoid impacts are futile...your Mavic will have already collided with the perceived object. RIP M2P.

sar104 · Jun 2, 2019

pjd900 said:
I haven’t performed a search yet, but I’m wondering what the live video latency is with the Mavic 2 Pro.
I surmise that, with a 1-2 second video delay, while attempting to fly in close proximity to to immovable objects...quick reactions by the operator to avoid impacts are futile...your Mavic will have already collided with the perceived object. RIP M2P.

It's not 1 - 2 seconds, generally around 250 - 400 ms.