Hello, I've had the Mavic for a few month and everything has been great!

Today was a different story. I took off from a tabletop on my patio. The table is made of metal, painted brown and has cuts in it that you can see the ground through. Took off from it and landed before with no problem.

When I came back to land, I descended slowly and the Mavic did not recognize the table being there and landed a little hard and bounced back up. I decided that I should try and land on the brick paver patio instead. As I descended the Mavic did not pause and hover as it usually does with the safety landing feature. It continues like it did in the table. I thought I could just land it softly but it hit the ground and bounced up. I tried to hold the left joystick down hoping that it would land and shutdown but it bounced again and flipped. I then immediately pulled both joysticks down and torward each other to shut the motor off but it wouldn't shutdown!

The Mavic was in P-Mode and there were no warnings that I remember seeing. I do remember that vision was on the screen so it was active. The only thing I can think of is the patio pattern had something to do with it?  Flying over surfaces with identical repeating patterns or textures (e.g. tiling).

So far only damage I know of is propellers are all destroyed.

Any help would be greatly appreciated!

Thank you!!!

Bob

I have the Landing Gear Mod on; I wonder if that had anything to do with it.

I have the Landing Gear Mod on; I wonder if that had anything to do with it.

Do you have spare propellers to continue your flights?
- I'm just curious, if you had the spare props, can you try using the tap/slide to land function.

I notice some times I get some drifting when I'm flying flow (2 meters) on grass fields... sensors probably get confused because they all look the same.

Hey Clue, 3 out of the 4 propellers are wrecked. I have some ordered for delivery tomorrow so I will report back.

Thanks!

fansd83f0a2e Posted at 2017-2-5 18:12
I have the Landing Gear Mod on; I wonder if that had anything to do with it.

Shouldn't. I have a set of Ebay landing gear, and I've never had an issue with the landing.

Are you using IOS or Android? In Android there's an option to disable Landing Protection. Is yours on or off? On IOS, the option apparently doesn't exist, although I don't know if that's still the case with the newest version of Go 4 for IOS that was released in the past couple of days.

Guys,

Drone and Metal DO NOT MIX period....

Jason Lane Posted at 2017-2-5 19:41
Shouldn't. I have a set of Ebay landing gear, and I've never had an issue with the landing.

Are you using IOS or Android? In Android there's an option to disable Landing Protection. Is yours on or off? On IOS, the option apparently doesn't exist, although I don't know if that's still the case with the newest version of Go 4 for IOS that was released in the past couple of days.

Hey Jason,

I am on iOS iPhone 7.  I remember seeing Vision on the Screen so I'm thinking that the protect mode was on. I think it possible that the tabletop that has see through slits confused the drone and when I moved the drone a few feet away from the table it didn't have enough time to get its baring before I started to descend. There definitely wasn't any hold from the drone when descending it just continued down to the ground.

Will be testing it out tomorrow.

If anyone has any system checks I can do to make sure motors, sensors and everything else is running ok please let me know.

Thanks for the reply Jason!

Bob

dronist Posted at 2017-2-5 20:19
Guys,

Drone and Metal DO NOT MIX period....

Wow!!! Great point!!! Thanks Dronist!!!

fansd83f0a2e Posted at 2017-2-5 18:12
I have the Landing Gear Mod on; I wonder if that had anything to do with it.

I've seen some of the mods covering part of the sensors (with the rear stand) i would suggest to remove it if it is your case

Sorry to hear about your crash, Bob, Could you please sync your flight records then provide me with your DJI account email and the exact date/time this occurred?
I'll help to review it.
Besides, is your DJI account email address the same as your forum email?

I will test that today CuaC! It doesn't go over the top of the back bottom camera, but I would say it hinders the field of view. Thank you!

Thank you Mindy. I will do that for you today.

The Mavic sets down extremely well under full manual control without any active aides interfering with the process. I had landing protection on the first few times I flew but have since disabled it (Android).  And yes, metal surfaces are bad news.

fansd83f0a2e Posted at 2017-2-5 20:26
Hey Jason,

I am on iOS iPhone 7.  I remember seeing Vision on the Screen so I'm thinking that the protect mode was on. I think it possible that the tabletop that has see through slits confused the drone and when I moved the drone a few feet away from the table it didn't have enough time to get its baring before I started to descend. There definitely wasn't any hold from the drone when descending it just continued down to the ground.

at landing downward obstacle avoidance is off ..................... (warning message)

was "precision landing" and "terrain check" switched on in DJI GO ?

Jdwyier Posted at 2017-2-6 06:53
The Mavic sets down extremely well under full manual control without any active aides interfering with the process. I had landing protection on the first few times I flew but have since disabled it (Android).  And yes, metal surfaces are bad news.

I agree. I tend to leave Landing Protection off, and I find it quite easy to bring it down for a gently landing. Although I usually just hand catch.

dronist Posted at 2017-2-5 20:19
Guys,

Drone and Metal DO NOT MIX period....

RIGHT?  No one mentions this huge variable!  
And the "well I've done it before" LUCK variable ever present...  


Could the downward cameras have something on them?  Perhaps caused from debris or fingerprint.  Had mine bounce once when I changed my mind...  Oops.

DJI Mindy Posted at 2017-2-6 00:29
Sorry to hear about your crash, Bob, Could you please sync your flight records then provide me with your DJI account email and the exact date/time this occurred?
I'll help to review it.
Besides, is your DJI account email address the same as your forum email?

Hi Mindy, I synced the logs. My email is the same. Date/Time O5/02/17 16:19hrs.

Thank you very much Mindy!!!

Hey Angelo, I didn't notice any warnings. However after the crash I charged the battery and started the simulation. A few times when I landed, the warning you mentioned came up; " Landing Downward Obstacle Avoidance Is Off." I assumed it was part of the Sim but now I'm starting to wonder.

Using Pro4 on IPhone.

Thanks!!!

Why take off from a table top?

B Mahoff Posted at 2017-2-6 06:01
I will test that today CuaC! It doesn't go over the top of the back bottom camera, but I would say it hinders the field of view. Thank you!

How did it go when the rear stand was removed? I've seen reports of other people having trouble with those kind of landing gears installed, as they cover partially or totally some of the sensors, so the mavic gets confused.

B Mahoff Posted at 2017-2-6 17:11
Hey Angelo, I didn't notice any warnings. However after the crash I charged the battery and started the simulation. A few times when I landed, the warning you mentioned came up; " Landing Downward Obstacle Avoidance Is Off." I assumed it was part of the Sim but now I'm starting to wonder.

Using Pro4 on IPhone.

No, this not only in the sim ........ It should pop up everytime You initiate landing/RTH provided the downward obstacle avoidance is set to ON in DJI GO during flight (prevents to ram Your MP into ground when flying close to the ground, which would be a "controlled flight into ground" in general aviation)

Jeffrey.hickman Posted at 2017-2-6 20:45
Why take off from a table top?

Why not ?

Better than grassy/muddy/gravel-ground .................

Jeffrey.hickman Posted at 2017-2-6 20:45
Why take off from a table top?

Just because it was there. No real reason, but won't be doing it again.

Angelo26 Posted at 2017-2-7 01:07
Why not ?

Better than grassy/muddy/gravel-ground .................

And that is very true Angelo!!! I guess I should say I won't do it off a metal table.

DJI Mindy Posted at 2017-2-6 00:29
Sorry to hear about your crash, Bob, Could you please sync your flight records then provide me with your DJI account email and the exact date/time this occurred?
I'll help to review it.
Besides, is your DJI account email address the same as your forum email?

I did as you asked Mindy. In case you are confused, I changed my user name to B Mahoff from Fanboy--------

Thanks!

B Mahoff Posted at 2017-2-7 07:04
And that is very true Angelo!!! I guess I should say I won't do it off a metal table.

Oh yeah, METAL table is something VERY different ................

I T/O from wooden tables only .............................

Angelo26 Posted at 2017-2-7 01:05
No, this not only in the sim ........ It should pop up everytime You initiate landing/RTH provided the downward obstacle avoidance is set to ON in DJI GO during flight (prevents to ram Your MP into ground when flying close to the ground, which would be a "controlled flight into ground" in general aviation)

Hey Angelo, I'm getting a little confused. Are you saying if I have the Downward Obstacle Avoidance on, it will give me a message saying that the Downward Obstacle Avoidance is off when I start to land?

I guess that makes sense because if it stayed on then you wouldn't be able to land.

I guess I've never notice that as I'm always looking at the MP when landing except for in the Sim.

I didn't turn anything off unless the latest update to the app defaults it to off.

Thanks!

CuaC Posted at 2017-2-7 00:25
How did it go when the rear stand was removed? I've seen reports of other people having trouble with those kind of landing gears installed, as they cover partially or totally some of the sensors, so the mavic gets confused.

Hey CuaC, the blades didn't make it here yesterday. Should be here today and if it stops raining I will test it and hand catch if it does cause a problem. It will be nice to figure this out so others don't go through this if it's the landing gear. The rear landing gear definitely changes the field of view of the read camera. I did see the guy at Drone Valley use the same ones with no problem; that's why I bought them.

Will let you know. Thanks!

Weather was to bad to fly today. Will test tomorrow.

DJI Mindy, were you ever able to look at my log file?

B Mahoff Posted at 2017-2-7 07:17
Hey Angelo, I'm getting a little confused. Are you saying if I have the Downward Obstacle Avoidance on, it will give me a message saying that the Downward Obstacle Avoidance is off when I start to land?

I guess that makes sense because if it stayed on then you wouldn't be able to land.

Sorry, dunno if standard setting is on or off (didn´t check in December when I got my MP and set everything to ON since I am still learning )

I realized that message from the very first beginning since I checked every function carefully at the beginning when I started to learn how to fly MP

B Mahoff Posted at 2017-2-7 07:17
Hey Angelo, I'm getting a little confused. Are you saying if I have the Downward Obstacle Avoidance on, it will give me a message saying that the Downward Obstacle Avoidance is off when I start to land?

I guess that makes sense because if it stayed on then you wouldn't be able to land.

The exact message I see on my screen is "Descending. Exited Visual Avoidance System" This pops up only at the final stage of RTH (descending), and also when auto landing my Mavic from 0.5m. I notice that sometimes the message is quite delayed, and doesn't actually show up on my screen until after the Mavic has touched down.

Thank you Jason and Angelo!!!

Ok Guys, I was able to test the MP today. Everything seems to be working fine.

I took off to about 100' and brought her back down and she paused descending about 3 feet off the ground, stated that she was landing, warning came up that obstacle Avoidance was disabled and then she continued down to land.

Another test I tried was to take off, bring her down to land and then just before landing, take off again and then try to land. She didn't not pause descending and did not give verbal warning that she was landing.

I shut her down and started back up, took off and landed and everything was good again; pause, warnings.....

I then put the landing gear on and it did not effect landing. I tried return to home as well two times and everything worked out perfect!

For some reason I was under the assumption that when landing and holding the left joystick down at full throttle the drone will pause about 3 feet up, hover and then come down very easy regardless whether the throttle is held at full power desend. It appears that when doing that I still have to make an effort to land slowly where as with h return to home gives a nice slow controlled decent.

I thought that the drone takes over the decent after the pause on a manual landing.

All that being said; I'm concluding that the Metal Table was the Problem!

Can't believe the build of this drone! Just two very very minor scratches and no damage to anything that I can see except for all the blades!

DJI Makes a Great product to say the least!!!

There should be auto landing at finally when you land

WYHSniper1007 Posted at 2017-2-8 12:05
There should be auto landing at finally when you land

Hey Sniper, yeah i just noticed that sometimes it takes over and slowing descends and sometimes it doesn't. I think it might be having a hard time reading the ground sometimes. Will be testing again with and without landing gear.

Thanks!

B Mahoff Posted at 2017-2-8 17:11
Hey Sniper, yeah i just noticed that sometimes it takes over and slowing descends and sometimes it doesn't. I think it might be having a hard time reading the ground sometimes. Will be testing again with and without landing gear.

Thanks!

Normally there should always be auto landing at the end

I landed about 7 times today. When I landed in the dead brown lawn that is all the same color Avoidance was not disabled and when it got to the ground the alarm would go off that there was an obstacle. I tried landing on cement and it did the controlled landing 3 out of the 4 tries.

I will try autolanding tomorrow in the same spots. Didn't have time today.

I wonder if something is wrong with my sensors. I didn't have the landing gear on.

B Mahoff Posted at 2017-2-9 18:59
I landed about 7 times today. When I landed in the dead brown lawn that is all the same color Avoidance was not disabled and when it got to the ground the alarm would go off that there was an obstacle. I tried landing on cement and it did the controlled landing 3 out of the 4 tries.

I will try autolanding tomorrow in the same spots. Didn't have time today.

I'm having the same kind of issues you are experiencing. The controlled landing works on mine about 50% of the time (I fly with both DJI Go 4 and Litchi). Seems to work less often after longer flights. First time it happened was after the firmware update around Christmas time.

I've landed in all light and ground conditions and there is no pattern for when it will/won't work. I now just assume it isn't going to work. Had a few close calls when I expected it to and didn't.

Had few days ago similar experience. At 53% Start  Auto-Landing........descending without any reason, no alarm, just the "landing Message" Hitting Pause Button and the red ohne did Not work at all!  I was  close to the trees  and close to a Heart-attack..... But lucky cause the steering-sticks did react and so i was able to make a few  corrections for "Save" landing  Maybe its a battery-issue because that happened three times, but only with one of my three batteries
Use my Mavic with iPad Mini2 , DJIGo4, and Landing Gears Extension......
First time it happend 1month ago, Samsung S4, DJIGo4, NO Landing Gears !!!