Something Went TERRIBLY wrong

[ralphel21]

I was doing a range test on my phantom 3 pro today, (with faa aproval) and something went terribly wrong. I was at 6351 feet with 45 percent battery, when I decided to turn arround. The phantom was flying normaly when randomly it gave me the motor overload error. It then swerved around at only 4-6 mph. It then suggested that I start RTH, and with my blood pressure rising I said yes. It then streightened out, and started home at 8-13 mph which was slower than I anticipated. Then randomly the aircraft lost all speed towards me and shot right at 45 mph with random twists and turns (shown in the picture) and got further, and further from me (7000 + feet). After trying unsucssessfuly to disable home lock, I watched in horror as my phantom did the dance of the sugar plum fairy. It ran the battery down to 15 percent when it went into rapid decent mode, and I could move it along the x and y axis. I was able to swerve it off its corce on to the trees and watched as the altitude dropped to 290 feet at which point I lost signal. We spent all afternoon tracking it down and we found that it had landed gracefully, but had flipped upside down when it landed on a hill. My phantom is fine but my confidence isn't. What went wrong, and how can I make sure it never happens again. NOTE: I had full gps the whole time, and my firmware is up to date. Thanks, Eli

 

[PHANTOM_PILOT13]

Check your motors spin all 4 and tell me if they all have a nice sound to it, if you hear a little different noise rather than the rest of your motors tell me

 

[sar104]

We need the flight log to answer your questions.

https://www.phantomhelp.com/LogViewer/Upload/

 

[Numone]

Hi Ralpel21.

Gawd, you were lucky it didn't end up in the pool!

I suggest you upload you flight log and let the experienced people here take a look...
https://www.phantomhelp.com/LogViewer/Upload/

 

[Numone]

We need the flight log to answer your questions.

https://www.phantomhelp.com/LogViewer/Upload/

Beat me to it!

 

[ralphel21]

I was doing a range test on my phantom 3 pro today, (with faa aproval) and something went terribly wrong. I was at 6351 feet with 45 percent battery, when I decided to turn arround. The phantom was flying normaly when randomly it gave me the motor overload error. It then swerved around at only 4-6 mph. It then suggested that I start RTH, and with my blood pressure rising I said yes. It then streightened out, and started home at 8-13 mph which was slower than I anticipated. Then randomly the aircraft lost all speed towards me and shot right at 45 mph with random twists and turns (shown in the picture) and got further, and further from me (7000 + feet). After trying unsucssessfuly to disable home lock, I watched in horror as my phantom did the dance of the sugar plum fairy. It ran the battery down to 15 percent when it went into rapid decent mode, and I could move it along the x and y axis. I was able to swerve it off its corce on to the trees and watched as the altitude dropped to 290 feet at which point I lost signal. We spent all afternoon tracking it down and we found that it had landed gracefully, but had flipped upside down when it landed on a hill. My phantom is fine but my confidence isn't. What went wrong, and how can I make sure it never happens again. NOTE: I had full gps the whole time, and my firmware is up to date. Thanks, Eli Flight Records are also included.
View attachment 82541

 

[Oso]

@ralphel21 - I uploaded your flight per the earlier requests from @sar104 and @Numone

Here's the flight:
DJI Phantom & Mavic Flight Log Viewer - PhantomHelp.com

 

[ralphel21]

Thanks so much @Oso

 

[ralphel21]

Typo at @Oso

 

[Meta4]

Thanks so much @Oso

It's going to take a while to go over things fully but it looks like wind could have been a big factor.
What can you say about wind conditions that day?

 

[Oso]

It's going to take a while to go over things fully but it looks like wind could have been a big factor.
What can you say about wind conditions that day?

I agree. To me, wind is very clearly the root cause here.
I feel as if this could have mostly been avoided with more of an understanding of how wind, especially at altitude, impacts the P3.

 

[ralphel21]

Wind 10-12 mph, but it should have assisted me or been static, because I never got a "high wind fly with caution" error. It was just weird what happened at 13:13 with at the exact moment the battery hit 25. It was like it entered atti mode with a strong wind. Thanks again for your help Meta4

 

[Numone]

Yep, AC seems to be fighting the wind and battery was struggling to maintain power.
Just as a matter of interest, are you on iOS or android?

 

[ralphel21]

Ios

 

[ralphel21]

I live streamed the whole thing

https://www.facebook.com/video.php?v=456877714665890

 

[Meta4]

Thanks so much @Oso

The short version is that you were at 400 feet in a strong and gusty wind.
The wind at 400 feet was significantly stronger than 10-12mph.
It assisted you ... going outward but you were fighting it coming home.
The High Wind warnings are usually a false alarm so ignore them anyway.
You got real warnings though if you look at your speed going outward.
Around 9 minutes the Phantom was consistently above 40 mph and reached 46.9 mph.
The only way it can do that is with a strong tailwind.

On the way back with full stick your speed is varying between 12-22 mph and at 10:28 (still with full stick) it drops below 5 mph.
When you are flying at full stick and making 46 mph or 12 mph, that should be ringing alarm bells telling you something about wind.

You stayed up at 400 feet and left the Phantom to fight the winds there the whole way.
If you had come back down below 100 feet you would probably found the wind was only half as strong.

Poor awareness and flying away high up in a tailwind will always cause problems.
Take this one as a lesson in what not to do.

 

[Numone]

I think you should've reduced altitude to drop out of the wind, but your "GO home" altitude seems to be set at 390'?

 

[Numone]

.....but Meta4 said this before me!

 

[Meta4]

The lessons for anyone reading this are:

Be aware of wind direction.
Be aware that wind higher up will be stronger.
Be aware of wind effects on your indicated speed.
Don't fly downwind in strong winds - you will have to fight a headwind coming home
Don't stay up at altitude fighting a strong wind.​

 

[ralphel21]

Thanks A TON, just so you know at my location i was under the tree line, so my only option was to fly at a high altitude to combat loss of signal. As you can see in the live stream my signal cut out at 260 feet when through pythagorean theorem you can see that assuming that the signal travels in a straight line my signal was cut out by the trees. I thought of that option, but thought it was too risky.