Fly-Away into Wall - I was 2 meters away and could not stop it

[Henfri]

Hello,

when approaching to land, the drone kept moving forward, despite full back stick.
I have no idea what happened.

Could someone with experience please have a look at my logs?

Greetings,
Hendrik

 

[Meta4]

Could someone with experience please have a look at my logs?

Yes ... if you can post the data someone can look into it for you.

There are a couple of options ...

1. Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report

 

[Henfri]

Ah, my apologies... I had uploaded the log with my post, but must have made a mistake.
However, the hint of using Airdata is good for privacy:

Please let me know, if you need the raw data.

Thanks for your help,
Hendrik

 

[Meta4]

Please let me know, if you need the raw data.

Yes ... the actual numbers are what's needed.
You'd have to tick the share box on Airdata for that.

 

[Henfri]

Ok, here we go:

 

[Meta4]

Ok, here we go:

I've had a look at the data but don't have much time available to look into it properly.
I can see where you were moving slowly forward (south) and pulled back on the right stick at 1:50.4 for 2.2 seconds.
The data shows a collision occurring at 1:52.1.

When you pulled the stick backwards, the drone pitched back which slowed the drone as it should have.
I can't see much more.

Perhaps @slup can look into the incident and come up with more.

 

[Henfri]

Yes, that is in line with my observation.
However, the drone was moving forward slowly. maybe 0.5m/s or so.
Full back stick, in front of a wall (i.e. no wind from aft) should stop the drone in no time, no?

 

[msinger]

when approaching to land, the drone kept moving forward, despite full back stick.
I have no idea what happened.

Here's what I see in the flight log:

• 1m 50.3s: Drone traveling forward at 5 MPH
• 1m 50.4s: Elevator moved to full down position and drone started to brake
• 1m 52.1.s: Drone impacted wall

So, I guess you're asking if it's unusual for a Mavic Pro to take more than 1.7 seconds to come to a full stop while traveling at 5 MPH.

According to the data, it looks like you might have been successful if you started braking a few seconds earlier.

 

[Henfri]

Hello,

thank you!

Elevator moved to full down position and drone started to brake

Elevator? Was I in plane mode?

So, I guess you're asking if it's unusual for a Mavic Pro to take more than 1.7 seconds to come to a full stop while traveling at 5 MPH.

According to the data, it looks like you might have been successful if you started braking a few seconds earlier.

You should have seen it. It looked like slow-motion. Also the pitch hardly changed. Normally, when you make full aft stick, the pitch changes to maybe -30°. Optically, this was more -5°.

Really, if you would have stood beside me, you would also be sure that there was something odd.

Greetings,
Hendrik

 

[Meta4]

You should have seen it. It looked like slow-motion. Also the pitch hardly changed. Normally, when you make full aft stick, the pitch changes to maybe -30°. Optically, this was more -5°.

Really, if you would have stood beside me, you would also be sure that there was something odd.

The events of a collision aren't always the way the flyer remembers.

You were flying slowly and centred the right stick for three seconds from 1:50.1.
The drone pitched back at 6° to slow down.

Then flying at only 2.3 metres/sec at 1:50.4, when you pulled the right stick (that's the elevator control) fully back.
The drone's pitch quickly went to 14.3° and stayed pitched back and slowing until 1:51.9, when the speed had slowed to <0.2 metres/sec.
The collision shows in the data at 1:52.1.

The drone pitched back and slow down.
Because it was flying very slowly, the max pitch angle required was much less than when flying fast.
The drone slowed to almost 0 m/s in 1.5 seconds.

The data doesn't back up your thread title as it shows that the drone didn't fly away at all.
It followed your joystick inputs properly.

 

[Henfri]

And do you consider it normal, that with full back stick I cannot stop from 2.3m/s within 1.7s? That is 0.13g - peanuts.

The events of a collision aren't always the way the flyer remembers.

Yes, I realize that. Whenever an aircraft crashes, you find people saying that the engine was burning.
So, let's stick with the numbers ;-)

You were flying slowly and centred the right stick for three seconds from 1:50.1.

Should the drone not stop when the stick is centered anyway?

Greetings,
Hendrik

 

[Meta4]

And do you consider it normal, that with full back stick I cannot stop from 2.3m/s within 1.7s? That is 0.13g - peanuts.

That depends on how aggressively you've adjusted the braking.
Your drone didn't appear to be acting unusually.st

Should the drone not stop when the stick is centered anyway?

It will always take some time to come to a stop and won't stop instantly.
You only left the stick centred for 0.2-0,3 sec ... not enough to bring the drone to a stop.

Another point that hasn't been mentioned yet is that while you had the right stick pulled full back, you also had it pushed partway to the right, so while the forward velocity was slowing, there was a positive velocity to the right.

 

[Wild Drone Pilot]

Hello,

when approaching to land, the drone kept moving forward, despite full back stick.
I have no idea what happened.

Could someone with experience please have a look at my logs?

Greetings,
Hendrik

This can not be good

 

[msinger]

This can not be good

That occurred post crash.

 

[Wild Drone Pilot]

That occurred post crash.

Yeah still not good
I have lost two my error many other close calls not so sure it was me.
And some times I know it was the drone 100%
some crazy stuff that I will never understand
Keep Flying! It only gets better.
I hope

 

[msinger]

Yeah still not good

The logs can spew all kinds of false flags after a crash has occurred. It likely doesn't mean an ESC was faulty and/or in a bad state prior to the crash.

 

[Meta4]

Yeah still not good

The error messages you are concerned about indicate that the prop was obstructed after hitting something 1.2 seconds after the drone ran into an obstacle and tumbled 6 feet to the ground.
They are a result of the collision and don't indicate anything that caused the crash.

And some times I know it was the drone 100%
some crazy stuff that I will never understand

A good look into the flight data solves a lot of mysteries and helps understand what actually happened.
It's very rare that flight data shows incidents were caused 100% by the drone.

 

[TonyPHX]

You hit the wall.

 

[Henfri]

Hello,

I tested the braking today and indeed it is less agressive than I though - but still I would claim (also checking with an independent witness (my son)) that it was unusual and like in slow-motion. Still I think that the full back stick should have been more than sufficient.

Then, I wanted to test the same situation. But I never managed to come even close to the wall: The obstacle avoidance system became active and quickly stopped the drone.
Why did it not protect me during the crash? It did not even warn me.

Here the Logs of the Flight

Best regards,
Hendrik

 

[Wild Drone Pilot]

The error messages you are concerned about indicate that the prop was obstructed after hitting something 1.2 seconds after the drone ran into an obstacle and tumbled 6 feet to the ground.
They are a result of the collision and don't indicate anything that caused the crash.

A good look into the flight data solves a lot of mysteries and helps understand what actually happened.
It's very rare that flight data shows incidents were caused 100% by the drone.

How about 20 feet away 15 foot over a river and the drone batteries RC are all good OEM and nothing you can do will make it move, land or??? That happened to me. RTH saved it or until the battery dies and it drops in the water I could only watch.