Hundreds of Flights First Crash Help P3 Pro

Phantomfreak · Jan 25, 2016

Impilot51, 2.5 would be the GO app version, not firmware. The latest firmware is 1.6, are you talking about the GO app or the firmware?

impilot51 · Jan 25, 2016

I just acknowledged that. I was talking about firmware, and it should be 1.5 is bad, not 2.5. Old age brain fart. 2.5 is Go, and is fine. Again, my apologies.

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rhwd2003 · Jan 25, 2016

Did you guys see the video I posted?

neven · Jan 25, 2016

Well battery doesn't look too good but not bad enough to cause this. Compas went crazy and I guess it wasnt you moving the gimball like mad on that descend. My guess is something happened to "CPU" part of drone.
Next step in diagnostics will be downloading a "blackbox" .dat file from drones built in SD card. Instructions are easy to find here on forum.

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John Locke · Jan 25, 2016

It appears your craft lost it's compass calibration somehow mid flight at 10:42. That's happened to me recently for the first time, and I'm on 1.6 firmware. When it loses Compass, or a compass error occurs, the bird automatically goes into ATTI mode. You may have mistaken ATTI for "going crazy" since the 9mph eastern wind you had would carry your craft east, then you correct with Westerly compensation to hold the hover, etc. If you haven't flown in ATTI mode much this might induce panic, since the craft isn't as stable and appears to be doing things you don't want it to do, especially in wind. However, only 1 second after it loses compass and goes into ATTI (drifting East) it appears the blades touched something, as in hitting a tree limp or something that obstructs the motor from turning.

When I lost Compass, it was similar. I made two flights in the same area. But on the third flight my compass went whacky only 30 seconds into the flight. Fortunately it wasn't windy, no trees were around and I easily brought the bird back and landed it, then I recalibrated. I'm still not sure what happened that day a couple weeks ago. It's still a mystery to me. I was at the beach and the bird was over scrub brush far away from any metal or structures about 75' high, and bingo,compass error warning, which enabled ATTI mode. Kinda strange.

BudWalker · Jan 25, 2016

rhwd2003 said:
Guys I have made hundreds of flights with my P3 Pro and never had an issue. I had flown on christmas but did not do the latest updated that was pushed on 12/22 until last week. I flew that morning after the update and everything was fine. Next flight that afternoon I flew for 10+ minutes and had 45% battery left on my descent to end my flight i was maybe 100 feet altitude and all the sudden it starts going crazy jerking in all four directions like it was unstable coming down. I tried everything hitting the sticks back up, left, right...etc and it would not stop coming down jerking in all four directions like it was very choppy. So I immediately start running for it to try to catch it and it lands on the top of it flipped upside down and I grab the leg and then it is still stuck in full throttle trying to take off props spinning as fast they could. I was doing everything I could to try to hold the phantom from flying off again. I was not holding teh controller I had set it on the ground so nothing was telling it to try to take off again. I ended up having my son come over and try to push the sticks to shut it off and it would not respond to that. I then tried to reach up with one hand as the props are spinning full speed to try to shut the battery off and it would not respond to that. I ended up having to pull the battery while risking getting cut with the props, it was stuck in full throttle up at this point.

I have never had a crash or any types of issues, I know there are other thread on here but where in the world do I try to begin on what type of issue this was and what I can do to resolve it?

Thanks so much!

Your description sounds a lot like some flights I've looked at lately where propulsion was lost in one motor/prop. See Professional - Need Help With P3A Crash | DJI Phantom Forum It may look like a compass issue but, the P3 actually is spinning. If you want either I, @Luap, or @TheRealNick to look at please retrieve the .DAT and DropBox so one of us can take a look.

rhwd2003 · Jan 25, 2016

BudWalker said:
Your description sounds a lot like some flights I've looked at lately where propulsion was lost in one motor/prop. See Professional - Need Help With P3A Crash | DJI Phantom Forum It may look like a compass issue but, the P3 actually is spinning. If you want either I, @Luap, or @TheRealNick to look at please retrieve the .DAT and DropBox so one of us can take a look.

Thanks for a response, I cant seem to get my phantom to mount on a mac to get the .dat file does anyone have any tips on that? I have tried everything.

TheRealNick · Jan 25, 2016

rhwd2003 said:
Thanks for a response, I cant seem to get my phantom to mount on a mac to get the .dat file does anyone have any tips on that? I have tried everything.

You have to put it into data mode as well using the dji go app. It is under the craft settings and then advanced....

Meta4 · Jan 25, 2016

John Locke said:
It appears your craft lost it's compass calibration somehow mid flight at 10:42.

Not compass related.
If you look at the compass notifications and also check against the altitude, you'll see that something more was happening at 10.42.
Those compass indications are a symptom of a crash - not the cause.

Meta4 · Jan 25, 2016

rhwd2003 said:
I know I shouldn't push 100% down on landing but ya know.

???
There's nothing wrong with using 100% down for descending - unless you have prop guards fitted.

rhwd2003 said:
.... it lands on the top of it flipped upside down and I grab the leg and then it is still stuck in full throttle trying to take off props spinning as fast they could. I was doing everything I could to try to hold the phantom from flying off again. I was not holding the controller I had set it on the ground so nothing was telling it to try to take off again. I ended up having my son come over and try to push the sticks to shut it off and it would not respond to that. I then tried to reach up with one hand as the props are spinning full speed to try to shut the battery off and it would not respond to that. I ended up having to pull the battery while risking getting cut with the props, it was stuck in full throttle up at this point.

It's not clear here ... did you use CSC for emergency stop and did it fail to work? ... or did you try other things and not use CSC?

rontam · Jan 25, 2016

I am curious what was the cause of your problem.. I did notice that while descending the unit kept switching from gps to Patti several times. I assume this was u trying to get control. We're u initially in P mode or FPV. ?

TheRealNick · Jan 25, 2016

I would definitely like to see the .dat file, it does look like you were descending with full down for a bit before it started spinning. I am not sure if that could have caused it. I know a lot of people say you can do full down, but from flying other RC helis they seem to act werd when you do this so I have formed a habit of not doing it. If the compass direction in the file matches the actual orientation of the aircraft then it is probably not a compass issue, but with the .dat file we could rule it out...

Meta4 · Jan 25, 2016

TheRealNick said:
like you were descending with full down for a bit before it started spinning. I am not sure if that could have caused it. I know a lot of people say you can do full down, but from flying other RC helis they seem to act werd when you do this so I have formed a habit of not doing it.

Other machines might not have the offset motors of the P3 which prevent VRS on full speed descent.
It's 100% safe to descend at full speed in a P3 without prop guards.

TheRealNick said:
If the compass direction in the file matches the actual orientation of the aircraft then it is probably not a compass issue, but with the .dat file we could rule it out...

The compass had nothing to do with the problem.
The only time compass data looks wrong is when it has already crashed.
It's a symptom, not the cause.

TheRealNick · Jan 25, 2016

Meta4 said:
Other machines might not have the offset motors of the P3 which prevent VRS on full speed descent.
It's 100% safe to descend at full speed in a P3 without prop guards.

The compass had nothing to do with the problem.
The only time compass data looks wrong is when it has already crashed.
It's a symptom, not the cause.

It might be 100% safe to descend at full speed, but I am not sure of that....it is a hard habit to break for me.

A good example of a compass error is shown in this post:

An example of bad compass calibration | DJI Phantom Forum

which references this video....

So I tend to agree that a compass error was not the issue in this crash.

kandelin16 · Jan 25, 2016

I do know that descending with the throttle all the way down can cause a quad to crash.
Vortex ring state - Wikipedia, the free encyclopedia

Quadcopter Flight School: Vortex Ring State (The Wobble of Death)

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impilot51 · Jan 25, 2016

kandelin16 said:
I do know that descending with the throttle all the way down can cause a quad to crash.
Vortex ring state - Wikipedia, the free encyclopedia

Quadcopter Flight School: Vortex Ring State (The Wobble of Death)

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Earlier models this is true. P3 is not prone to this. Motor angle offset has fixed this in the P3.

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wooglin · Jan 25, 2016

kandelin16 said:
I do know that descending with the throttle all the way down can cause a quad to crash.
Vortex ring state - Wikipedia, the free encyclopedia

Quadcopter Flight School: Vortex Ring State (The Wobble of Death)

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The p3 is not very susceptible to Vortex Ring State. No saying it wont get a small amount of wobble but very little. I also as a habit do not like to descend straight down but my p3 handles it just fine. Yesterday I flew in very windy and cold conditions at got a slight bit of wobble doing a straight down descent where there was not much room for landing and it handled it just fine correcting the wobble after about 2 seconds. Gimble corrected movement so its not even visible in the video.

My guess is that DJI has programmed the IMU unit to detect this condition and it applies diferential thrust to recover. Having flown quads for some time it is rather difficult to recover, but so far I have not been able to get my P3 to even think about getting into this situation. It could also be that the P3 is coded to not allow for an overly rapid decent.

kandelin16 · Jan 25, 2016

wooglin said:
The p3 is not very susceptible to Vortex Ring State. No saying it wont get a small amount of wobble but very little. I also as a habit do not like to descend straight down but my p3 handles it just fine. Yesterday I flew in very windy and cold conditions at got a slight bit of wobble doing a straight down descent where there was not much room for landing and it handled it just fine correcting the wobble after about 2 seconds. Gimble corrected movement so its not even visible in the video.

My guess is that DJI has programmed the IMU unit to detect this condition and it applies diferential thrust to recover. Having flown quads for some time it is rather difficult to recover, but so far I have not been able to get my P3 to even think about getting into this situation. It could also be that the P3 is coded to not allow for an overly rapid decent.

Ok my bad.

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kandelin16 · Jan 25, 2016

impilot51 said:
Earlier models this is true. P3 is not prone to this. Motor angle offset has fixed this in the P3.

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My bad.

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