Mavic Pro Fly Away Recovered

I hate to say it, but I am so disappointed in the MavicPro. I bought it out of a need for work, it’s not a toy to me. I don’t expect it to be the best, but I want to be able to feel in control of it. What I have found, you need witchcraft skills, not aircraft skills to control this. :/ Is this a bad one?

I am a qualified hang glider, paraglider, almost ready to complete my light aircraft license… I am pro photographer and worked in IT for years as a sysadmin in a tech company. I tell you this fluff, so you know, I am not uncle bob who just unboxes and flies stuff without knowing about firmware, following best practice. The nature of my job, personality and flying experience means I respect air law and follow manuals. I’m the guy who watches the videos, writes a pre-flight check to follow, decided the flight route, returns the drone when down to about 40% battery and doesn’t fly far away. I make sure I watch the best practice in calibration,  check and double check things that can cause the dreaded fly away, and thought today’s blue sky clear day would be the ideal day to try the new MavicPro I bought a few days ago. I waited 5 days for the best weather before trying it, I was not the guy who just rushes to fly it on day 1. I was ready, did nothing stupid, followed all advice and instructions and I am left never wanting to fly this broomstick again. It has a mind of its own.

I bought the MavicPro Nov 2nd 2017, updated the firmware to most up to date Nov 4th 2017, and flew it today on Nov 5th 2017. Just for anyone reading this in the future.

The first flight started off well, I followed all the correct procedures. I picked a great spot, an area I know well, with clear churches in the distance, I would not have any disorientation, and that was a good decision. Because after it lost GPS it was hard to see and control. In the end on the first flight it lost GPS (when it had 18 satellites on a clear blue sky day in a sleepy tiny city in Finland to start with, no big built up buildings, no metal near take off (including in structures) and the second proper flight of the day at sunset, it runs lost GPS had compass errors and went running in the total opposite direction of my flight back into the town. I managed to get them back using the video camera feed, but it was very stressful watching it just run away into a cit and nearly land on a building roof. I think I need to check myself into Hogworts for a potion to calm my nerves.

Firstly, before everyone asks, I really did carefully read all the manual, watched Youtube videos on each step, tried my friends Phantom 4, had some lessons. I calibrated the controlled, updated app, calibrated the compass on site on every flight, updated firmware (no errors), updated controller, made sure phone, controller, drone all 100% battery. I set the home point, checked it on the map, decided my flight plan, just go up, rotate take some photos, picked two good spots. I did not take off too fast, I approached it like a real aircraft flight. I research the spots and picked them because no people, no metal, clear spaces, but each near the small town I know well. I was away from power, metal, walls or constructions that contain metal. I could see no no covert street lamp style mobile masts, I was by the ocean at sunset and in an outside sports arena, it was like a stadium with a bank of brick and mud on the very outside permitter, 20m plus from me at the nearest point, no roof, no metal, and about 20m clearance around me in both cases. Both hard gravel ground. It was a blue sky day with very little wind.

1st Flight Lost Signal of GPS but Regained Control - First flight problems. I don’t recall the times or details of this except it reported the similar errors I noted down on flight 3, and was hard to control, so let me jump to tell you about flight 3, as I have the details fresh in mind and on paper.

2nd Flight No Problem

This was ok, as I just took off, showed my wife basic controls, stayed in beginner mode, under 30 meters and came back.

3rd Flight Fly Away, more like RUN away in the opposite direction

This was at sunset tonight, November 7th. After just stable flight at about a height of 11m less than 1 meter away for about a minute, taking photos, showing my wife the controls. I started to fly away about slowly, I was only  5-8 meters away and then I started to increase height to about 40m, then I brought it back overhead, about 1 minute away (forward of my location). I then was about to start moving out over the water, not far, and as I push forward 90% at first to get it going, smoothly dropping back to 80% then 60% forward, suddenly right at the point, this is now 1min 46sec into the flight,  errors started popping up, I think in this order:

• Weak GPS Signal
• Warning: Compass Error: Exit GPS-P mode
• Warning: In Flight, working IMU encounters heading exception, please switch to anti mode if craft behave abnormally
• Warning: Weak GPS signal. Positional accuracy may be compromised. Please fly with caution.
  

I think I was in ATTI mode, and those popped up slow close I was trying to see where it was, it went from flying forward away from me over the water to a hard reverse and right into the city. It was like the first flight but this time it just started flying away in the total opposite direction I was traveling, and was nearly out of sight, very hard to see over the town behind me.

2:20 into the flight, I thought I can do what my friend said "you'll never have a fly away or any issues, just press return to home” I pressed run to prevent the fly away, it warned me obstacle avoidance will be disabled during landing, (which it normally says on all other flights today (Day 1) which I find strange, even in beginner mode on a clear gravel field) and think nothing of that, it starts to land, then I realised no GPS!, crap… that won’t work then probably, and I noticed a pop up about it’s landing where it is. So I canceled, lucky as when I looked at the camera behind the pop up message the drone was about 30 cm (14m heigh from take off location) on top of an apartment block nearly landing on the apex of a metal shiny roof. After pushing the altitude stick forward fast, and stuffing tissue up my short legs ;), I used the camera and rotation to fly back to my location.

I also got 1 high wind warning on the flight, but the windmills were hardly turning, no trees were moving, that also seemed like an error.

I want to continue to use the MavicPro, but why would GPS be lost, why does ATTI mode sending it running all over the shop? Why does RTN talk about turning off collision avoidance?  Whey does sometimes in the same gravel massive empty area does it fully land, other times it stops and wants me to check to complete the landing.

I really feel like using this is a massive risk to peoples safety are there such things as BAD MavicPro’s, duds from the factory?

How do other users feel confident? I am in a town of 20,000 people, no buildings higher than 4-5 levels, sleepy town in Finland.

How do I run diagnostics? How do I not just put this in the cupboard and never touch it again?

Andy

Hi Andy.
https://forum.dji.com/forum.php? ... D402%26typeid%3D402

If you provide the flight logs (DAT files) from the flights where you had the problem I'll take a look at them. The instructions for accessing them are here, and once you've retrieved them you'll need to upload them to DropBox and provide a link to the file(s) in this thread. The correct files will have date and time values that correspond to when the flights occurred and will be at least tens (and probably) hundreds of megabytes in size. If you aren't sure which are the correct files then just include any that may be and I'll figure it out.

I'm sorry to read your post. Just to verify, has the drone been damaged or not? Did you check the performance later? According to your description, it's hard to locate the exact reason, please upload your flight records and fight data for analysis, thanks!

a. Download and install DJI assistant 2 from here: http://www.dji.com/mavic/info#downloads
b.Connect aircraft and PC,and power on the aircraft
c.Operate DJI assistant 2, find flight record and save

why would GPS be lost, why does ATTI mode sending it running all over the shop?

There are a lot of things to learn before you can be a proficient flyer.  Understanding what atti mode is and how it works is one of them.  In atti mode your drone either has no GPS signal or ignores GPS so it flies without position holding ability.  This is a bit like driving on ice with no brakes.
It also means that your Phantom will drift with wind or inertia.  The different flight characteristics in atti mode caused you to believe your drone was flying away (but it probably wasn't)

The compass is critical to safe flying .  The Mavic can fly without GPS but without compass, it's impossible to control properly.  If you get a compass error, the flight controller can't deal with conflicting data from the compass and GPS.  To deal with that situation, it ignores GPS data and your drone is now in atti mode.

That's probably how your Mavic ended in atti mode.
You need to look further to find out why it had a compass error.
This is most commonly caused by launching from on or close to a lot of steel and reinforced concrete is a very common cause.
You said:  I calibrated the controller, updated app, calibrated the compass on site on every flight,
This rings alarm bells as it's not necessary to calibrate the compass before flight and it could also cause problems.
Read P54 of your manual to see what DJI advise about calibrating your compass.
You should normally not have to calibrate anything.

I really feel like using this is a massive risk to peoples safety are there such things as BAD MavicPro’s, duds from the factory?
How do other users feel confident?
Other users build confidence with experience and find that the Mavic is very reliable.
Understanding how it works is the key.

How do I run diagnostics?
Go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions there to upload the .txt file from your phone or tablet.
Come back and post a link and someone should be able to help analyse it for you to see what caused the incident.

Thanks @Labroides I just returned from using in Iceland, used it a lot, still had many of the same problems, but really there has been no metal anywhere.   Since I often drive more than 50 miles between flights and I am so far north in the world, Finland, Iceland etc..., I read it's important to calibrate it each time.  I do it very carefully, have no metal on me, no metal or magnets in my phone case, away from concrete or any sources of metal, massive rocks, often in a field.

BUT, I have discovered I have been possible calibrating the compass incorrect. The manual and app advise different methods.

1. Rotate craft horizontally. (app and manual the same)
2. is just not clear... (manual and app advice different)

a) the manual shows pointing the camera down to the ground
b) the on screen app instructions show pointing camera forward with aircraft on side

Which should it be? I have been doing as per the app.

I also read about some models needing a back leg removed and rotated to twist the wires, as some models did not have twisted wires and that caused interference with the compass.

I agree, maybe since it was my second flight it was just wind and atti mode combined with the lack of GPS which sent it over the town.

Any thoughts appreciated.

Andy