P3 went spinning out of control and crashed!

[BudWalker]

Here is the line to the dat files. Let me know if you can get to my google drive.
Redirecting...

I'm trying to get that .DAT file using that link. Apparently Google Drive is waiting for you to approve my access to the .DAT file. You could also upload it to flylog.info and tell me the name of the .DAT so that I can retrieve it from there.

 

[phantom13flyer]

Sounds like toilet bowl effect from a bad compass calibration

 

[Mark The Droner]

I warmed up the P3 for a few seconds and then took it up to around 170 feet ...

I call this pilot error. MHO.

Why? Because not nearly enough time was spent doing the fundamental pre-flight procedures such as 1) waiting for satellites, 2) waiting for GPS lock, 3) waiting for home point recorded, 4) determining home point location lock is correct (and not 14 miles away), and finally, 5) launch and hover to watch for drifting/TBE.

It generally takes me at least 90 seconds to do all this, and that's if I get my seven satellites locked in quickly.

 

[ksavoie]

I call this pilot error. MHO.

Why? Because not nearly enough time was spent doing the fundamental pre-flight procedures such as 1) waiting for satellites, 2) waiting for GPS lock, 3) waiting for home point recorded, 4) determining home point location lock is correct (and not 14 miles away), and finally, 5) launch and hover to watch for drifting/TBE.
.It generally takes me at least 90 seconds to do all this, and that's if I get my seven satellites locked in quickly.

@Marknmd , I'm not sure what you are looking at but, I did a compass calibration in the middle of my yard, I had 14 satellites locked in, had gps lock, home point was recorded and in the correct location. I should have hovered longer, but there was zero drift for about 20 seconds.

 

[happydays]

Looking at the healthydrones information:

1. A notification comes in at 39 sec indicating propulsion output is limited to ensure the safety of the battery.
2. The compass appears to be screaming warnings all over the place.

You'll get a lot more info as others have stated via the .DAT file. However, I would ask what firmware you were using? If it is 1.5, then perhaps the battery saving itself as mentioned above. The latest firmware is supposed to stop this happening at lower temperatures.

Have you flown in this area before? It looks to me like the compass is getting a lot of interference which could explain the haywire behaviour. The .DAT file should tell a lot more.

Sorry for your loss.

 

[Mark The Droner]

@Marknmd , I'm not sure what you are looking at but, I did a compass calibration in the middle of my yard, I had 14 satellites locked in, had gps lock, home point was recorded and in the correct location. I should have hovered longer, but there was zero drift for about 20 seconds.

I was looking at the words in your opening post, and also the overview in your flight log which shows a total of 2 seconds on the ground. Maybe you didn't describe your launch and flight accurately. Maybe the log is wrong.

Sorry for your loss.

 

[BudWalker]

I'm still looking at the .DAT but it's clear the compass was not an issue

The time axis is offset 192.04 (motor start - battery on). Until the incident that starts happening at 210 the compass is normal, in fact very normal. The incident appears to be a propulsion issue with the Left Front motor/propeller. At 220 the A/C is spinning and the magMod value is to be expected.

Starting at 210 the LF is being commanded higher with a small increase in speed. Starting at 220 commanded is maximum (10000) and more increase in speed. I think this is a broken prop issue. Although, it seems that there wasn't a abrupt separation. Rather, it seems like the prop broke in the interval 210 to 220.

I'm still looking at this.

 

[BudWalker]

I was looking at the words in your opening post, and also the overview in your flight log which shows a total of 2 seconds on the ground. Maybe you didn't describe your launch and flight accurately. Maybe the log is wrong.

Sorry for your loss.

The log you're looking starts at motor start which was 192.04 seconds after the battery was turned on.

 

[ksavoie]

Looking at the healthydrones information:

1. A notification comes in at 39 sec indicating propulsion output is limited to ensure the safety of the battery.
2. The compass appears to be screaming warnings all over the place.

You'll get a lot more info as others have stated via the .DAT file. However, I would ask what firmware you were using? If it is 1.5, then perhaps the battery saving itself as mentioned above. The latest firmware is supposed to stop this happening at lower temperatures.

Have you flown in this area before? It looks to me like the compass is getting a lot of interference which could explain the haywire behaviour. The .DAT file should tell a lot more.

Sorry for your loss.

I was using Firmware v1.6.0040 and yes I flew in this area ( my home) probably 50+ times.

 

[ksavoie]

I'm still looking at the .DAT but it's clear the compass was not an issue
View attachment 39617

The time axis is offset 192.04 (motor start - battery on). Until the incident that starts happening at 210 the compass is normal, in fact very normal. The incident appears to be a propulsion issue with the Left Front motor/propeller. At 220 the A/C is spinning and the magMod value is to be expected.
View attachment 39618
Starting at 210 the LF is being commanded higher with a small increase in speed. Starting at 220 commanded is maximum (10000) and more increase in speed. I think this is a broken prop issue. Although, it seems that there wasn't a abrupt separation. Rather, it seems like the prop broke in the interval 210 to 220.

I'm still looking at this.

I will go back and look at the crash site for the missing pieces of the props.....If they are all near the tree then this will be strange......

@BudWalker thank you for your help!

 

[happydays]

Excellent work @BudWalker - the .DAT files and your interpretation of them is really excellent. Thanks.

 

[BudWalker]

Although I'm not a Dashwarian it was easy to make this video

using the profile that @Luap has provided. This profile can be obtained by going to
P3A/P Dashware profile for for Dat Files | DJI Phantom Forum

 

[AlexSP]

Excellent work @BudWalker

 

[phantom13flyer]

Very impressive analysis! !

 

[AlexSP]

IMO investigations like these, even though within our limited resources, are important to diminish speculation and above all, myth creation and dissemination. Not all shells crack, not all batteries fail, not all compasses go wacko. In fact I´d say the majority of P3s flying out there are just OK, with a few showing minor problems from factory and possibly many issues caused by us pilots, in one way or another. What is commonly known as "human failure"

 

[ksavoie]

I'm still looking at the .DAT but it's clear the compass was not an issue
View attachment 39617

The time axis is offset 192.04 (motor start - battery on). Until the incident that starts happening at 210 the compass is normal, in fact very normal. The incident appears to be a propulsion issue with the Left Front motor/propeller. At 220 the A/C is spinning and the magMod value is to be expected.
View attachment 39618
Starting at 210 the LF is being commanded higher with a small increase in speed. Starting at 220 commanded is maximum (10000) and more increase in speed. I think this is a broken prop issue. Although, it seems that there wasn't a abrupt separation. Rather, it seems like the prop broke in the interval 210 to 220.

I'm still looking at this.

I went back at lunch and looked for the pieces of the prop under the tree and I found just about all the pieces except for the tip of the left front prop.......maybe it did break mid air? See the pics in my google drive. I will look again tomorrow being that here are a lot of leaves to look through.

https://drive.google.com/folder/d/0B8UnzD-uv6fSa3Z3cHdnaWlkVnM/edit

 

[yawnalot29]

I call this pilot error. MHO.

Why? Because not nearly enough time was spent doing the fundamental pre-flight procedures such as 1) waiting for satellites, 2) waiting for GPS lock, 3) waiting for home point recorded, 4) determining home point location lock is correct (and not 14 miles away), and finally, 5) launch and hover to watch for drifting/TBE.

It generally takes me at least 90 seconds to do all this, and that's if I get my seven satellites locked in quickly.

I would very much disagree with your reasoning. Lets look at the facts.

All the reasons you have cited are necessary for GPS flight and RTH function. Under low GPS lock condition P3 goes into ATTI mode.

Many people purposely fly under ATTI mode for one reason or another.

Neither is OP leveraging RTH or triggering RTH.

I fail to see how lack of GPS signal would contribute to essentially an ATTI flight. Can you elaborate?

 

[RadRich]

Well now you're getting somewhere. You weren't using DJI props. As you pointed out, the tip could have been broken off before you flew it. You might have a case if you flew with the props that came with your P3.

 

[ksavoie]

Well now you're getting somewhere. You weren't using DJI props. As you pointed out, the tip could have been broken off before you flew it. You might have a case if you flew with the props that came with your P3.

YES they were DJI Props

Buy 9450 Carbon Fiber Reinforced Self-tightening Propellers (Composite Hub, Black with Yellow Stripes) | DJI Store

 

[RadRich]

Ok my bad