Aggressive drifting, aircraft disconnected, compass error, gps data exception

Piyau19 · Mar 15, 2018

We bought this P4P less than a month ago. Normal flights until these past few days. The first time it went out of control, we were flying at 300m altitude, 800m away and the first warning was the gps data exception, we loss all the gps,no satellite positioning, went into ATTI mode, and the aircraft was disconnected 3 times, few times compass error warnings suddenly popped up. Mind u that this all happened when we were trying to navigate it home. No visuals at some few times and was desperate to find our way back. It was safely landed with 10% batteries remaining. The drone somehow hovers steadily when it goes down to about 20m from ground. We decided to fly it again today just to check. 200m,steadily. Everything seems fine when suddenly the warnings started to came up again like spam and it was back to atti mode. We quickly dropped the altitude to 100m and the drifting was aggressive, lowering the altitude alone drifted it in odd directions to 20 to 30 meters in high speed. When we finally had it near,we thought it stabled like before,15 m to land point suddenly it shoots 20 m to the front in max speed,we didn't do anything to the RC it just went crazy and it was chaotic, luckily no one was around, nothing was standing in that direction. It hovers to land steadily and we hand-landed it because the battery was at 7% and it hovers because the P4P identifies the area as unsuitable for landing.
*We went high up for projects, it was done at remote areas,control environment,no buildings no towers,not even power grid.

What the hell happened to this drone can anyone help

Techcop50 · Mar 15, 2018

You haven't mounted anything on top center of the body (even a sticker) that might interfere with the GPS, have you?

sar104 · Mar 15, 2018

Need the logs - preferably the aircraft DAT file.

How to retrieve a V3 .DAT File from the AC

Fly Dawg · Mar 15, 2018

Just out of curiosity, you didn't happen to notice an "Ultrasonic Sensor Error" did you? If so, this would be the third one of these I have seen this week and only on P4's. Will need the log files to give you any information.

Piyau19 · Mar 15, 2018

No. Nothing. It still looks like how we bought it.

Piyau19 · Mar 16, 2018

sar104 said:
Need the logs - preferably the aircraft DAT file.

I have 1 problematic flight DAT file ready. But it's too big, could not upload it. I opened it up with DatCon, it shows that mid flight, 17 satellites suddenly dropped to 0 for a prolonged period before regaining just right before landing

Meta4 · Mar 16, 2018

Piyau19 said:
I have 1 problematic flight DAT file ready. But it's too big, could not upload it. I opened it up with DatCon, it shows that mid flight, 17 satellites suddenly dropped to 0 for a prolonged period before regaining just right before landing

Go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it gives you.

Piyau19 · Mar 16, 2018

Fly Dawg said:
Just out of curiosity, you didn't happen to notice an "Ultrasonic Sensor Error" did you? If so, this would be the third one of these I have seen this week and only on P4's. Will need the log files to give you any information.

sar104 said:
Need the logs - preferably the aircraft DAT file.

How to retrieve a V3 .DAT File from the AC

The gps health turns 0, satt number flat 0, turns into atti mode and recovers just right before landing

sar104 · Mar 16, 2018

Piyau19 said:
View attachment 96351

The gps health turns 0, satt number flat 0, turns into atti mode and recovers just right before landing

That’s not unexpected given your description, but without the actual DAT file it’s just guesswork as to why that happened. You would need to upload it to Dropbox or similar and post the link here so that we can see it.

Aussie markD1969 · Mar 16, 2018

How long have you been flying ? .. you start with , We bought this p4p . Sounds like you are new to this , flying at 300 mtrs and 800 out . So l guess it’s second hand ? ...

Fly Dawg · Mar 16, 2018

Piyau19 said:
The gps health turns 0, satt number flat 0, turns into atti mode and recovers just right before landing

Doing your own analysis is great, as many of us do. However, you asked for assistance and we can't do that without the actual log file to independently review. As @sar104 said it's just guesswork without that.

Skynet1 · Mar 16, 2018

I applaud all of you, Fly Dawg, SAR104 & Meta4, for your patience, and dedication to other pilots, both new and seasoned alike.
Keep up the great work gentleman.

Piyau19 · Mar 16, 2018

Hi guys sorry for the delay. We, my company, just bought this p4p. I, myself, have been flying Mavic Pro for over a year for another company. I only have limited resources and internet access and I'm still trying to upload the DAT files to dropbox, google drive took longer comparing to 17hours of uploading 2 files to dropbox. When it's done i will share the link here and I thanked you guys very much for offering some hand into this matter. But I was wondering should I try to downgrade the fw? I never did this before, but i know how to. I'm nervous because I just got a warning from the company and they say if I bricked it or crashed it, I'm the one who's paying. If it's totally fine, I'll downgrade it, and try to fly it again but if the problem persists, for sure it's not the fw.

Piyau19 · Mar 17, 2018

Dropbox - DJI_ASSISTANT_EXPORT_FILE_2018-03-16_10-45-32.DAT

Try this DAT file. Thank you!

sar104 · Mar 17, 2018

Piyau19 said:
Dropbox - DJI_ASSISTANT_EXPORT_FILE_2018-03-16_10-45-32.DAT

Try this DAT file. Thank you!

Neither of the DAT files in that set FLY107 and FLY108 are actual flights - just 2 minute power ups.

Piyau19 · Mar 17, 2018

This is so lame. I'll upload the right one soon

DroneB · Mar 17, 2018

Since December, my P4P had problems with the camera 'flipping' while pointing straight down. The update earlier this month fixed that. But the first flight after the update was a disaster. Everything checked out pre-flight, but 20-30 seconds into flight and a compass error popped up, no gps, no satellites, erratic and aggressive drifting, hard to control. Finally landed. Pre-flight checked out all good again. Took off, same issues 20-30 seconds into flight. I updated everything; calibrated compass and IMU. Still the same. Everything looked good on the ground but the P4P turned into a monster 20-30 seconds into flight. I live in a rural area, 200 acre farm field with no electrical, buildings or anything else to interfere. I finally took everything back to factory settings and started all over, including deleting and reinstalling DJI GO4 app and all the firmware. Finally, it's back to normal and flying the way it should. A takeaway from this is to do a test flight after every update and fly far away from anything it could erratically fly into.

Piyau19 · Mar 18, 2018

DroneB said:
Since December, my P4P had problems with the camera 'flipping' while pointing straight down. The update earlier this month fixed that. But the first flight after the update was a disaster. Everything checked out pre-flight, but 20-30 seconds into flight and a compass error popped up, no gps, no satellites, erratic and aggressive drifting, hard to control. Finally landed. Pre-flight checked out all good again. Took off, same issues 20-30 seconds into flight. I updated everything; calibrated compass and IMU. Still the same. Everything looked good on the ground but the P4P turned into a monster 20-30 seconds into flight. I live in a rural area, 200 acre farm field with no electrical, buildings or anything else to interfere. I finally took everything back to factory settings and started all over, including deleting and reinstalling DJI GO4 app and all the firmware. Finally, it's back to normal and flying the way it should. A takeaway from this is to do a test flight after every update and fly far away from anything it could erratically fly into.

this is exactly what happened to mine. Does the latest fw work fine? I downgraded the fw yesterday, but if yours works fine i will try to just factory reset and reinstalling dji go 4 apps again.

DroneB · Mar 18, 2018

Piyau19 said:
this is exactly what happened to mine. Does the latest fw work fine? I downgraded the fw yesterday, but if yours works fine i will try to just factory reset and reinstalling dji go 4 apps again.

I've flown 4 times for over 60 minutes total since upgrading from factory default and have had no problems. Everything is stable and performs the way it should. But it almost gives me sweaty palms because I don't trust it anymore. I hope this works for you.

Skynet1 · Mar 18, 2018

Hello all,
I can't say how many times I've read various concerns regarding those who have upgraded to a new firmware only to then report negative results, while others not so much. However, reading post #17 by DroneB made me think further. I'm certainly by no stretch of the imagination an authority in this area, but that particular posting made me think back to what was once suggested as a prerequisite to performing a firmware change. It was strongly suggested that you first format the SD card within the model before upgrading to a new firmware. To maximize success in this regard, this should be accomplished via the App. to essentially wipe clean any previous information which may then corrupt the new firmware version being downloaded.
I believe the steps DroneB performed to negate his issue was to wipe the slate clean and begin once again, a good move, but simply formatting the SD card first before performing any firmware change may have accomplished the same results.
As a matter of curiosity if there are any pilots contemplating an upgrade and would be willing to simply format the SD card beforehand via the Go App. It certainly wouldn't do any harm, and MAY hopefully alleviate many of the issues experienced.
Just reaching for the stars here.

As another POI, and once the download is completed, be sure to follow thru with other suggested download recommendations, eg.
1. Restart the radio controller & model.
2. Perform all necessary calibrations. eg. IMU, radio, camera, compass. etc.
All the best, and please feel free to make any further suggestions, or thoughts you may personally have to help alleviate this troubling process.