What do you make of this flight and minor crash?

[Cometstorm]

My house is in a heavy oak/hickory tree three acre lot wooded neighborhood. I've flown about twenty missions off my rear deck, climbing through the only "open canopy" area available... then doing neighborhood waypoints and orbits (usually Litchi).

One day last week after two uneventful and fairly lengthy waypoint runs, I just wanted to send her straight up off the deck to hover. It was getting dark and I wanted to show my wife the multiple Cree strobes.

Well, all heck broke lose right after takeoff. I was getting so much warning input that I was mentally overloaded.

Bird finally glanced off a roof gutter, inverted and crashed upside down on my concrete sidewalk, continuing to run and bounce upside down.

In doing so, I panicked and didn't think CSC stick shutdown. I grabbed the bouncing bird to pull the battery, and REALLY sliced up my left hand with the props. Not good!

Yes, those blades CAN cause serious injury and cut deep!

Well, it appears the only thing needed was prop replacement. Calibrations remained OK, and no shell cracks. Just had to wipe some blood off (yuk!)

Subsequent test flight a few days later (after prop replacement) went fine with video and pics.

But I cannot understand the sudden turn of events that took place at my standard location! No metal changes nearby, or anything like that. Just my private deck area!

I guess point E (WARNING! MOTOR OBSTRUCTED) indicates the first note of impending disaster, yet it has flown fine since the props were replaced (which was a result of the crash, well past Point E).

And I SURE as heck cannot understand the minus 1000 Feet + altitude readings noted on the below flight log!

Thoughts?

I

Airdata UAV - Flight Data Analysis for Drones

 

[With The Birds]

If you upload the log to the phantomhelp log viewer we may get more clues (airdata reveals significantly less information). It seems younkaunched almost immediately following power on and it is likely did not have a good GPS lock so AC was in ATTI mode.

 

[Cometstorm]

I'll be darned if I can find it! I know about doing the fileshare thing and whatnot. When I download the Llitchi flight logs, it has the two waypoint flights I did prior to the crash mission. But I can't find the crash mission itself. Just seems to be absent. I did cloud sync.

Funny, since I could get the crash mission to Airdata....

 

[Meta4]

I'll be darned if I can find it! I know about doing the fileshare thing and whatnot. When I download the Llitchi flight logs, it has the two waypoint flights I did prior to the crash mission. But I can't find the crash mission itself. Just seems to be absent. I did cloud sync.

Funny, since I could get the crash mission to Airdata....

Phantomhelp is very much preferred to Airdata for investigations.
Try rebooting your phone or tablet and see if that makes any difference.
If you really can't upload to DJI Flight Log Viewer .... then please tick the option in Airdata to share information (or something like that) and send a new link.

 

[Cometstorm]

Finally learned how to do the flight log viewer. Here's the link.

Man, that thing went bonkers! And all I wanted to do was go up, hover a few minutes, and then come back down on my elelvated deck, where I've launched from many times before (its not concrete....its one of the maintenance free (almost) poly things.

Wish to heck I knew what "speed error" and "Motor obstruction" warnings mean.

The motors are fine, even after post test (new props) flights?

DJI Flight Log Viewer - PhantomHelp.com

 

[msinger]

What happened right after you did the auto takeoff? It looks like you crashed into something about 19 seconds after that.

 

[Cometstorm]

First warnings appeared at abouot 25 secs...."motor obstructed" and "Satillite positioning off...fly with caution." My guess is that's when it hit the roof guttering, inverted, and landed upside down (props spinning) on the concrete walk.

I also notice my satellite count drops significantly at this point.

Some seconds later, you'll see tons of "compass errors" and "speed errors." That's probably when it when spinning upside down on the walkway?

At about 1 min, 18 secs.... It switches from ATTI (which was forced due to satellite loss), back to GPS. Maybe this is where I picked it up, and was holding it vertically trying to removed the battery in panic (thus satellite re-aquisition with GPS?). (but, the satellites go from 9 to 8 when GPS was re-acquired, so that doesn't make sense.)

At 2 min 49 secs, it says "motor overloaded. Aircraft will de-accelarate to ensure safety? I was no doubt fumbling with it at this point. Those props WILL CUT AND TEAR FLESH!

Shortly after that, all battery indicators turn yellow on the log.... That must'v been right when I was trying to pull the battery out.

I guess all the warnings were post impact with the guttering, thus the massive amounts of warnings given. What some of them mean, I do not know. Compass of course, I understand.

Why she drifted into the gutter to begin with I'll never know.... It was "supposed" to be a straight up auto-take off. No wind at play.

 

[With The Birds]

This is likely a simple case of you not having a sufficient number of satellites acquired and available to provide for P-GPS mode, the AC drifted in ATTI mode until it collided with the house.

 

[msinger]

Your Phantom made impact at 24 seconds into the flight log. All of the errors (which appeared after that point) are all related to the events that took place post crash. None of those messages are really useful since you already know how it crashed.

Why she drifted into the gutter to begin with I'll never know.... It was "supposed" to be a straight up auto-take off.

She was within 2.5 feet of the home point for the entire flight pre-impact. That's pretty good considering you were flying in poor lighting conditions. It seems you just didn't give her enough space to fly.

 

[msinger]

the AC drifted in ATTI mode until it collided with the house.

I don't see the AC switching to ATTI mode until post-impact.

 

[With The Birds]

I don't see the AC switching to ATTI mode until post-impact.

I see it happening at 25s (in the airdata log) which, from my experience, can be a bit slow in depicting the timing of an event (if it shows up at all). That’s why I prefer your log viewer.

 

[Meta4]

First warnings appeared at abouot 25 secs...."motor obstructed" and "Satillite positioning off...fly with caution." My guess is that's when it hit the roof guttering, inverted, and landed upside down (props spinning) on the concrete walk.

The important part of the log is:
0:03.4 - Liftoff using Auto function hovering until ...
0:24.4 when you give it a little throttle and rudder input with the left stick.
0:24.7 - the pitch, yaw and roll sensors are showing you have already bumped something and the Phantom is starting to wobble
0:25.6 - error messages start but these are all indications of the Phantom is tumbling and spinning.
As msinger said, all of the error messages are showing that the crash has happened, not what caused it.

 

[msinger]

I see it happening at 25s (in the airdata log) which, from my experience, can be a bit slow in depicting the timing of an event (if it shows up at all).

Check out the pitch of the aircraft right before that ATTI switch appears in the flight log. You can see it made impact before that mode switch.

 

[sar104]

Impact was at 24.6 seconds. At that point it had only drifted a few feet, which suggests that you were just flying too close to the structure for enough of a margin of error.

It switched to ATTI at 25.7 seconds purely as a result of the satellite count dropping after the crash. There were no error messages before the crash, the first one (Motor obstructed) coming at 25.6 seconds.

 

[Cometstorm]

You all are just too kind for evaluating all this for me.

A big THANK YOU!

I was sitting on the deck last night trying to replay this in my mind.

My best guess is that I got "sloppy" and set the bird launch a few feet closer to the house than normal.

Lesson learned...

Thanks so very much!

You're the best!