How can I ever trust her again?

[flyNfrank]

If I was to guess I would say the firmware had your setup as a different aircraft? And it could be the tech advising a IMU calibration because it could be a fail-proof considering the same software is used in the different aircraft.

I use to always do calibrations after firmware upgrades. But now that there is sensor readouts for the IMU and Compass I rarely to almost never calibrate anymore.

 

[rmb]

Good input. I actually posted a When to calibrate IMU and compass question in another forum (inspire 2 forum) to see if this differs amongst airframes

 

[kiwi flyer]

Is there a Guide or a Cheat sheet for the Mavic when to do the calibrations?

 

[SYC12]

OK that's a bit dramatic, but I am now reluctant to fly my Mavic. Here is the lineage of events leading up to this.

So I sent my mavic back for the second time for a camera/focus issue. Both times DJI said that they repaired the camera and gimbal for a cost of $175 which they warranteed. Actually they just gave me a refurb unit back and said they fixed it. Today I received my "repair" back for the second time with the same description, but this time they actually replaced the unit with what appears to be a new one (why wouldn't they tell you that they were giving you a brand new one?) anyway I opened the box, turned it on and it wanted me to do a firmware update. I did, then restarted, then did a complete IMU calibration, then restarted. I brought it out side and did a compass recalibration. I flew 200ft away and 124ft up and as I was turning back around I got and IMU Exception error and a Compass error and a warning telling me to switch to anti mode. (see screen capture). I lost control and the bird just started flying away. Fortunately I was able to regain control and land it. I got on tech support chat with DJI (Generally useless) and after a half hour of no help, he tells be that I have to send it back. Now furious I call to get a supervisor and surprisingly I did. He was incredibly nice and got me on with a tech guy that told be that a software error during my firmware update was probably the issue and told me to do the following. Go into DJI Assistant and do a factory reset. Then downgrade the firmware to the previous version and restart the mavic. Then upgrade back to the newest version of the firmware. Then restart. Then go to the calibration tab and do a calibration. Then unplug from the computer and do an IMU calibration (something EVERYONE SHOULD ALWAYS DO after a firmware update as well as reset all of you settings especially you RTH settings) After IMU calibration restart. Lastly take it outside and do a compass recalibration. At that point it should fine. So I did all that and had one very close and cautious flight. Now the real problem for me is that I don't feel like I trust it anymore. It was terrifying! That said if I don't start flying up and away I will never know if it is fixed and, if it does it again and I can't get it back I could hurt someone. Remember unlike most in-flight issues without a GPS it can't RTH in a pinch as it has no idea where it or home is. And without compass you have no idea what direction it is pointing and you are flying in. On the positive side it is however a great reminder why EVERYONE should ALWAYS fly LOS.

Also here is a Vimeo link to a movie with the flight data (password is "mavic"). What you will notice is that as I am rounding the turn long before the warning I was ascending but the "height" on the left was not moving. Also when I regain GPS and I am approaching the Mavic I am within 15 feet of it and yet the distance is showing 180 - 190 ft.

View attachment 15682

Something does not look right on the screenshot on your first post.
Is the Home location corrected shown? If the Home is corrected shown, then it was not a good choice because it was surrounded by trees. Your Mavic and RC transmission will be blocked by trees.

 

[geigy]

... My biggest issue was/is that in 4 years and 4 different models of phantom, and inspire1 and a mavic, nothing really bad has ever happened, so I am not very use to the heart in the throat feeling.

Yes, exactly! Not a feeling that is, or should be, easily forgotten! Suddenly the Mavic just charges off in a random direction.

I believe in most cases this is due to a poor GPS lock, either at takeoff or during the flight. I do wish the Mavic had an ATTI mode.

I wonder if hitting Pause would help or not (probably not, since it would still want to "Pause" at a fixed location)

 

[Jamison74]

IMU calibration is done at the factory in a controlled environment, humidity, temp, etc. DJI reps have posted about this on the forums before and were very clear. Do not calibrate IMU unless prompted by the app. Compass calibration, meh do it or don't not really the same risk involved as an IMU calibration. I think their customer service reps have an index card in front of them that reads "update firmware, calibrate everything, send it back"
I myself have never done an IMU calibration and only 1 compass calibration out of the box in November. 55 flight hours with my Mavic with zero issues.

 

[rmb]

Something does not look right on the screenshot on your first post.
Is the Home location corrected shown? If the Home is corrected shown, then it was not a good choice because it was surrounded by trees. Your Mavic and RC transmission will be blocked by trees.

I see why you would think that. I took off at my house (under tress) and fly it out and down the road to the field where the blue dot is. I should have updated the RTH when I got there.

 

[Lake_Flyer]

Without an Atti switch it is really hard to learn how to fly properly.
The Mavic, although positioned as a quad that 'anyone can fly' leaves many unexperienced pilots to yell 'it flew away' and in the lucky cases: 'I barely managed to land it safely', when it drops into Atti. As a first quad it is not suitable. Best is to have a cheap manual quad to practise with.

Atti is just a flight mode with which you have to compensate for wind, that's all. Nothing serious. But people need to learn how to fly in this mode, which isn't even close to real manual (without anything automatic). That, and flying without a screen, purely in line of sight, learning to keep and gain back orientation, is a good practise for when the app would freeze up (which happens often).