Mavic Air 2 crashes into Lighthouse

[Van Belle Jean Marc]

Various options are described in this thread:

Mavic Flight Log Retrieval and Analysis Guide | DJI Mavic Drone Forum (mavicpilots.com)

Airdata is an easy App to have this automatically. You can even connect it to your login at FJI if you want that. Look, these are the apps i use with FJI drones on my iPhone(s). +je

 

[Order66]

Crashing is always a pilot error. i think you confused the different sensitivity between sports or manual mode and the safer standard mode. The remote and acceleration is much much faster when in manual mode. The fact you saw lights, means you could not see how close you were. Do not feel ashamed of crashing a drone in ‘pilot’ mode. You learn most from it, especially after having paid quite a lot for repair... i crashed it between trees but could repair the camera and am extra carefull now, but i expect another crash if i continue to fly. It is a matter of time... i drove more than 2,5 million kilometer with cars and motorbikes but still i am not perfect! +je

So crashing can't be caused by equipment failure, or by an external factor such as a bird flying into it?

 

[Icarus-50]

I'm guessing that since you were orbiting the Lighthouse, you simply hit it because the obstacle sensors dont work unless you're going straight ahead or reverse. Just curious as to which OBX Lighthouse this was. I was there over xmas and filmed several of them.

Bodie Island Lighthouse. I

 

[Icarus-50]

Thank you. Agree, even perfection is relative. I meant knowledgeable about control unit functionality

I'm guessing that since you were orbiting the Lighthouse, you simply hit it because the obstacle sensors dont work unless you're going straight ahead or reverse. Just curious as to which OBX Lighthouse this was. I was there over xmas and filmed several of them.

Bodie Island Lighthouse, near Kill Devil Hills.

 

[Icarus-50]

i am thankful for such insightful responses, Thank you! I will post the logs to understand what happened: RTH, my “forward” stick mistake, etc. appreciate it very much.

 

[Icarus-50]

I've visited many lighthouses and spent time inside them.
There's nothing there that would exert any mysterious pull to draw a drone towards it.
Even outside the lighthouse world, I can't think of anything, anywhere that can do that.


Without seeing the recorded flight data, which will probably show exactly what actually happened, my assumption is that what mysteriously drew your drone toward the lighthouse was .... RTH following loss of signal when you flew behind the lighthouse.
The RTH path would have been right through the lighthouse and *bingo* it's game over.

My guess above is pilot error, but if you post the recorded flight data, that will confirm whether it's correct.
And if not, it should give some useful clues.

Thank you, I will post the logs.

 

[Van Belle Jean Marc]

So crashing can't be caused by equipment failure, or by an external factor such as a bird flying into it?

That can happen. Every pilot of a Boeing that takes off knows that. He takes that responsibility. We should never blame the machine... i am a motorbiker: my biggest efforts go to correct errors other drivers make as well. Upto now i only had one accident and i was not enjured, apart from some blue spots on my hip and brest when i decided to jump off the motorbike when the car driver started to panic and freeze. If you crash against a bird, if your equipment is not maintained... i have nobody in my pilot environment who had an engine error, except in heavy rain where the battery got water (known problem) and fell out. He admitted as well he should not have taken off so... that he made an error as pilot. Weather conditions IS the responsibility of the pilots. Even tyre pressure on a motorbike and car is the ‘pilots’ responsibility, it is on the checklist and that is why i have PTMS on my vehicles as well (1% of motorbike/car incidents come from to low pressure on tyres followed by overheating or taking a sharp corner with too low pressure where the tyre looses all air suddenly or even explodes). Overpressure is hardly an issue. +je

 

[Icarus-50]

Here are the last few seconds of the video.

 

[sar104]

Here are the last few seconds of the video.

They definitely are not.

 

[Icarus-50]

Thank you, I will post the logs.

I wasted 4-5 hrs today trying to download flight data files from my mini ipad. I can see some files that show the path of my flight with 1 or 2 settings popping up, but no table with flight data. ITunes does not show DJI apps and two Apple/iTunes reps told me that they had never heard of apps being displayed in the left navigation menu. I made at least 9 calls to DJI, some hanging up on me others just read out from some manual, w/o being able to provide real assistance. I did get a repair order ticket from DJI and one of their reps said they may replace the drone because it was still under warranty but a new one would cost me $69. So I am sending in the damaged drone and wait to see what they say.

Regarding the crash, I discovered that when the drone took off the ground, it automatically set the RTH height at 30 meters, which is lower than the height of the Lighthouse. So, when I lost sight of the drone (it was behind the lighthouse) and panicked, I clicked the RTH button and since the drone was below the height of the Lighthouse, it went straight towards it and hit it.

So that was my discovery by looking at the flight video on my iPad.

 

[sar104]

I wasted 4-5 hrs today trying to download flight data files from my mini ipad. I can see some files that show the path of my flight with 1 or 2 settings popping up, but no table with flight data. ITunes does not show DJI apps and two Apple/iTunes reps told me that they had never heard of apps being displayed in the left navigation menu. I made at least 9 calls to DJI, some hanging up on me others just read out from some manual, w/o being able to provide real assistance. I did get a repair order ticket from DJI and one of their reps said they may replace the drone because it was still under warranty but a new one would cost me $69. So I am sending in the damaged drone and wait to see what they say.

Regarding the crash, I discovered that when the drone took off the ground, it automatically set the RTH height at 30 meters, which is lower than the height of the Lighthouse. So, when I lost sight of the drone (it was behind the lighthouse) and panicked, I clicked the RTH button and since the drone was below the height of the Lighthouse, it went straight towards it and hit it.

So that was my discovery by looking at the flight video on my iPad.

Would I be right in guessing that you didn't bother reading the guide that I linked to in post #16?

 

[Meta4]

I wasted 4-5 hrs today trying to download flight data files from my mini ipad. I can see some files that show the path of my flight with 1 or 2 settings popping up, but no table with flight data.

The file that's needed is a .txt file with a file name like this:
DJIFlightRecord_2021-05-04_[16-02-03].txt

It should only take two minutes to find it with the instructions in post #18 or post #16
If you try to open it, it will just look like garbage because the file is encoded.
Just post that file and someone will be able to make sense of it for you.

 

[Icarus-50]

The file that's needed is a .txt file with a file name like this:
DJIFlightRecord_2021-05-04_[16-02-03].txt

It should only take two minutes to find it with the instructions in post #18 or post #16
If you try to open it, it will just look like garbage because the file is encoded.
Just post that file and someone will be able to make sense of it for you.

Meta, I read and re-read and re-read it. It does not makes sense to me. I write manuals and these instructions are confusing. They are not instructions they are just "need to access.." or "the logs are in ....". They don't tell me how to get to the files. I read the same text to more than one DJI agent and more than one Apple agent, and they could not understand it either. But I thank you for directing me to a place where this information probably exists but I am unable to "see" it. There is no DJI or Apps icon in iTunes, and there is no upload button or icon on my iPad either. I spent hours playing with iTunes and even reinstalled it. Look at the text here: "The TXT logs are in Apps>>DJI GO 4>> FlightRecords. the same method can be used to access DJI FLy files in DJI Fly>> FlightRecords, but ..." Where is APPS? In iTunes, somewhere in IE, on my device? I do not see it anywhere.

From the text in the link you provided:
With iOS devices running DJI GO 4 you need to access the app files via computer, either using iTunes or with a file system browser such as iExplorer. The TXT logs are in Apps » DJI GO 4 » FlightRecords. The same method can be used to access DJI Fly files in DJI Fly » FlightRecords, but with DJI Fly they are also accessible using the iOS Files app by selecting Browse » On My iPhone » DJI Fly » FlightRecords.
END OF TEXT

 

[Icarus-50]

Would I be right in guessing that you didn't bother reading the guide that I linked to in post #16?

sar, I did read it but didn't make sense to me. Now, just now, I tried everything again from what is in post #16 and 18, and I found the file!!! So, thank you for pushing me to try again. I am posting it here now. Again, thank you.

 

[Icarus-50]

The file that's needed is a .txt file with a file name like this:
DJIFlightRecord_2021-05-04_[16-02-03].txt

It should only take two minutes to find it with the instructions in post #18 or post #16
If you try to open it, it will just look like garbage because the file is encoded.
Just post that file and someone will be able to make sense of it for you.

Meta, my apologies to you. After reading your post again, I opened the other instructions link/file and found a good step-by-step guide. It took me to the file. Again THANK YOU!. I am posting the files separately.

 

[Icarus-50]

Here are the three files related to this event.
Sar and Meta, thank you.

 

[sar104]

Right - so the problem was that although you said that you went into Tripod mode to fly past the lighthouse, that's not actually what you did - at 349 seconds you went back into ActiveTrack and then used the sticks to manually fly up to the structure. Once it got really close the ActiveTrack algorithm failed, as indicated by the 3201212 Horizontal distance to subject too short error, and it collided.

 

[Icarus-50]

Right - so the problem was that although you said that you went into Tripod mode to fly past the lighthouse, that's not actually what you did - at 349 seconds you went back into ActiveTrack and then used the sticks to manually fly up to the structure. Once it got really close the ActiveTrack algorithm failed, as indicated by the 3201212 Horizontal distance to subject too short error, and it collided.

Sar, great job interpreting it. You know, once I crashed I was so crushed that I forgot the specifics on how I got there. I do remember switching to ActiveTrack. But why do you think the algorithm failed and crashed into the structure? I thought it was because I activated the RTH and my max altitude for some reason was auto set to 45ft/m, which is lower than the height of the lighthouse. Does RTM de-activate the sensors?

 

[sar104]

Sar, great job interpreting it. You know, once I crashed I was so crushed that I forgot the specifics on how I got there. I do remember switching to ActiveTrack. But why do you think the algorithm failed and crashed into the structure? I thought it was because I activated the RTH and my max altitude for some reason was auto set to 45ft/m, which is lower than the height of the lighthouse. Does RTM de-activate the sensors?

RTH was never activated - it was in ActiveTrack continuously until impact. I'm not really familiar with how ActiveTrack works when combined with heavy stick input, but you were applying full forward elevator and full right aileron approaching the lighthouse, and the FC was yawing counterclockwise to keep it in view. But it looks like you basically just spiraled it into the structure.

 

[IceCoffee]

Am I the only one who will say that this flight was irresponsible on the part of the operator.
Luckily, no one got hurt by the drone or falling debris.