HELP!! Mavic Pro Platinum Slow Loss of Altitude Leads To Spectacular Crash

[svfdfireman]

Hello Everyone,

I am a Drone NOOB! So be gentle. LOL! I've been a lurker here on this site for a number of months.

A little about my background...only so you know I'm not a TOTAL NOOB when it comes to "tech" stuff...

I would describe myself as a "Vintage Dude" (50 y/o dad that enjoys tech hobbies. i.e. building my own and others computers, repairing iPhone screens that my 3 kids always manage to break, etc.) I am a career firefighter with an added job description of Communications Technician on large complex wildland fires (Forest Fires) i.e. setting up communications equipment in mountainous terrain so the firefighter's portable radios will be able to communicate out of deep canyons back to the Incident Command Post, to the aircraft working the fire etc.

Enough about me...

I purchased my Mavic Pro Platinum last July (07/18) and of course took my time researching before and after buying it (I didn't even fly it for the first 2 days after receiving it because I wanted to keep learning as much as I could prior to my maiden flight of my $1200 toy for the first time) from various YouTube tutorials, reading info from this site and others trying to learn from everyone in this hobby.

I have a tendency to get "wordy" so I apologize in advance... but basically after some weeks of flying I became comfortable with my flying skills and would zip around in sport mode every now and then just having fun when not shooting pics or video. So fast forward to last week... I was in sport mode zipping around and experienced an issue that caused the drone to crash SPECTACULARLY! Have you ever seen a drone cartwheel for about 20 yards? Well if you have, and if it was your own drone, I'm sure the same F word repeated in quick succession is not new to you. Anyway, I started a speed run at about 10' above ground from about 150yds away in a straight line back to me. As I am looking at the telemetry on my iPad everything seemed to jive with what I'm actually seeing/watching.. At about 50yds from me I glanced back down at my iPad one more time to check my speed then back to the aircraft just in time to see MAGNIFICENT cartwheels and other SPECTACULAR acrobatics only a drone could do after striking the ground at a relatively fast speed.

So after reviewing my flight logs (noting timing of various points along its flight path and comparing it to the video I was actually recording at the time of the crash, I am stumped as to what happened. I use Airdata for my flight logs and I hopefully have shared the link correctly so you could all (those that are interested anyway) maybe share some insight on this crash that I'm just not grasping. If you are able to see/watch my flight log, pay particular attention to the reading I was receiving about my altitude at the point it makes a sharp deviation to the left (West) at about the 6min 47.3 sec This is the point of impact.
I probably did make some mistakes (yes you can bust my balls my feelings won't be hurt) on this run so please feel free to point those out to me. I won't learn unless helpful flyers such as yourselves point those out.

Surprisingly, the Mavic sustained only broken props. I was lucky considering what I watched it do after striking the ground.

So since this is my first real post, I followed the "Problem Format" somebody suggested when posting crashes/problems

Hopefully if I did everything right as far as the "flight logs link" down below, once you're there you should be able to click on the NOTIFICATIONS menu and then click on HD player and it should play the the flight in its entirety. I made the entire flight available so anyone can see what warning messages in the upper lefthand corner were being displayed. Unfortunately I didn't have screen recording started on the iPad so you could see what I was seeing.

Problem? -- Unexplained Loss of Altitude resulting in high speed (Sport Mode) crash

Was unit in a crash? Yes and "It was spectacular"

What have you tried so far? Analyzing flight data and asking for input, scratching head, (probably my balls too)

What device are you using? iPad Mini 4

Firmware? ( aircraft, remote controller)? The most recent from DJI for both remote and aircraft

What Go app version are you using? DJI Go 4 ver. 4.3.3

Any modification? None

Did you change anything or install any apps? No

Do you have a video or pictures of the problem? Yes Flight Data here - Video here -

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[RayOZ]

You were zooming around too close to the ground. As you accelerate in sports mode, your altitude drops a little. In your first run, @~4:38, your altitude dropped around 1.2m as you accelerate. On the second run, you started even lower to the ground.

 

[beach_Dr]

I agree with RayOZ, too low for zooming in sport mode. None of sensors (obstacle avoidance/ulrasound) will work in sport mode, aircraft attitude too great. I have read about other crashes at low altitude in sport mode, and also experienced slight drops in altitude in sport mode. Which doesn't make a big difference, unless you're only 3m / 10" up to start with...

Glad it's only props to replace!

 

[svfdfireman]

Hey guys thanks for the replies. I'm sure you are correct about the starting out too low. But if you notice my altitude on my flight logs it was reading between 11' and 14' altitude at the time of impact. In the picture below note where the drone is at the point it deflects suddenly to the left. This is the impact point.

 

[Deleted member 109911]

Usually if you begin a flight with a short hover test then you will be able to notice a decrease in altitude almost look as if the bottom sensors are focusing on the ground. So a little downward maybe up first then down. If that happens recommend to calibrate your telemetry go to ... then to picture of drone, continue to sensor state the page directly before compass calibration it will ask to fold drone set on flat area , then put on its right left set it upwards and on its back. Then restart drone try hovering again if it doesn't work try your compass calibration. Again with a hover finally trying a vision sensors calibration with dji assistant. Plug in to your computer. That's all I got from dealing with my crash and sitting through the repair for all of my Mavic pro,alpine and platinum. Alpine is the only one that hasn't touched the ground that shell is 70 bucks. Lol I painted the first one before putting shell on and also tried to use car wrapping. Dad was a firefighter 37 years. He was a mechanical tinker guy as well.