My P3P crashed, DJI not cooperating

[m0j0]

See my first comment above. The OP was not at the low or critical battery level.

Yes but there is still an audible warning which he may not have heard because of the boat.. Additionally there is a visual notification that stays on the screen. Adding to that it appears that stick input brought the bird down lower than the preset RTH height.

 

[ferraript]

Your Phantom crashed at 55 feet above the home point

good analysis
I will just add one missing piece
I believe there was big pressure change during the flight so the altitude readings were way off incorrect at the end of the flight

according to rapid change in roll/pitch/yaw values, I'd say point of impact is at 16:52:08.632
and even though altitude (OSD.height) says that bird is at 54.1 ft (over homepoint, but as it's over water, it's the same at the end), the real altitude according to VPS is only 3.9 ft
and because bird was traveling home at 19 mph, crash was inevitable

so I agree that it was 100 % operator's error - he panicked during the RTH process and steered the bird (with his negative throttle inputs) directly into that rock

 

[m0j0]

In this case, the deal doesn't seem lame at all. DJI was not at fault, so their offer is quite generous.

True, 25% off seems like a great deal.

 

[Sealybomb]

I'm waiting on my quad to turn up in the post.....reading threads like this is giving me a good learning curve before I start!! I'm sorry for your loss buddy but at the same time thank you! [emoji106] I soooo hope I don't smash into a rock!!!


Sent from my iPad using PhantomPilots mobile app

 

[m0j0]

I'm waiting on my quad to turn up in the post.....reading threads like this is giving me a good learning curve before I start!! I'm sorry for your loss buddy but at the same time thank you! [emoji106] I soooo hope I don't smash into a rock!!!


Sent from my iPad using PhantomPilots mobile app

You will not crash. I'm telling you this thing is rock solid In the air. You can comfortably fly it over just about anything you want. Remember this, DJI owns about 70% of the drone market. For every X Star Premium or Typhoon H sold there are probably 50 Phantoms. So you will see more crashes reported more problems reported its just math. Go fly your bird and don't worry about it.

 

[henick]

Yeah people don't tend to post much about how they had a great uneventful flight and their product performed as advertised...

Bad news travels fast.

 

[MikeyOnline]

Well, as unfortunate as it is for you, I learned something. I missed the part in the manual that states that stick input can alter RTH altitude! Good to know, although I don't think I see the logic in that. Maybe I can see it honoring UP on either stick, but not down (you either need to get home faster or you need to raise the RTH altitude). I would think RTH should be pretty autonomous: what if something was wrong with the RC or it was getting interference? Or as in this case, it initiates RTH without you realize it and you are still operating the controls. Is that an option that can be turned off, where RTH ignores user input unless you cancel it either via the screen or RC? IMO, I'd prefer that. As smart as these things are, they could at least limit it so that during RTH, you can't go below the RTH set altitude without canceling RTH.

Mike

 

[msinger]

Is that an option that can be turned off, where RTH ignores user input unless you cancel it either via the screen or RC?

No.

 

[Chris_P]

Well, as unfortunate as it is for you, I learned something. I missed the part in the manual that states that stick input can alter RTH altitude! Good to know, although I don't think I see the logic in that. Maybe I can see it honoring UP on either stick, but not down (you either need to get home faster or you need to raise the RTH altitude). I would think RTH should be pretty autonomous: what if something was wrong with the RC or it was getting interference? Or as in this case, it initiates RTH without you realize it and you are still operating the controls. Is that an option that can be turned off, where RTH ignores user input unless you cancel it either via the screen or RC? IMO, I'd prefer that. As smart as these things are, they could at least limit it so that during RTH, you can't go below the RTH set altitude without canceling RTH.

Mike

Thats exactly my issue with all this.... It all happened within seconds. My initial thought was interference and the throttle input was me trying to regain control. I'm still not clear on a couple points regarding the whole RTH design. It makes no sense for me to have some control (altitude) in RTH but not be able to stop the **** bird from flying forward. From what I'm reading, touching the throttle stopped it from reaching the 30M RTH altitude I programmed but it still flew off and hit an object which is precisely what the RTH altitude was supposed to prevent. Then there is the issue with the altitude readings, they were way off and that also concerns me ... Plus I DID update my RTH location several times and that didn't register although I have a GPS enables iPad that was connected to the Internet. So yes, there was pilot error here but there were also faults in my opinion in the design and operation if the DJI software that also contributed to the crash.

 

[MikeyOnline]

Regarding the altitude mystery, if you look at the log, it was flying at about 54 feet altitude at 24 MPH and then it went from 24 MPH to zero in about 0.6 seconds. Immediately thereafter, you can see the altitude go down from 54 feet to 10 feet over the next second or so. Just looking at the data, I'd say it was at 54 feet going 24 MPH, hit one of those pine trees in the distance, and then tumbled down the pine and onto the rock/water. The end altitude does say 10 feet so it would seem the altimeter was working. Is that possible? How well could you see it?

Mike

 

[Chris_P]

Regarding the altitude mystery, if you look at the log, it was flying at about 54 feet altitude at 24 MPH and then it went from 24 MPH to zero in about 0.6 seconds. Immediately thereafter, you can see the altitude go down from 54 feet to 10 feet over the next second or so. Just looking at the data, I'd say it was at 54 feet going 24 MPH, hit one of those pine trees in the distance, and then tumbled down the pine and onto the rock/water. The end altitude does say 10 feet so it would seem the altimeter was working. Is that possible? How well could you see it?

Mike

Just as in the picture, I had a clear unobstructed view the entire time. I was standing on the swim platform bringing it in to land. Look at the flight path, there was no going to trees then to the rock, it flew directly towards the rock. I was bringing it i to land on the swim platform of the boat, it was almost within my reach when it took off directly towards the rock, it did a few cartwheels then fell in the water.

That why these altitude numbers make absolutely no sense to me. It was probably at the height near the top of the boat when it took off, that's surely not 54 feet.

 

[MikeyOnline]

Not calling you a liar by any means! But given the GPS locations, data, and the endpoint(s) shown on the map, it appears to have hit the tree in the area I've marked with the circle, and then tumbled along the path marked down into the water. If I were DJI, that's what the data tells me, so I bet that's why you're getting the 20% offer.

Mike

 

[Chris_P]

Well maybe you are using the same log viewing program as DJI but the one posted in the first response shows me this.... the path is no where near the trees. Its directly into the rock as I described. It seems different programs extract different fight paths? I'm not sure why the different flight paths .... I can assure you, it had no contact with any tree. It never flew near any tree. It flew directly into the rock then into the water. According to the logs, I was at 48' when it reported a motor obstructed error. It was already crashed at that point,

 

[flyNfrank]

Chris_P, I uploaded your flight log here.

According to your flight log, it appears the following occurred:

• Your RTH altitude was set to 30 meters.
• At 16m 9.4s, your Phantom started returning home due to low power (this occurs when the "Smart Return-to-Home" feature is enabled in DJI GO).
• The home point at that time was the original home point since the home point was never reset after takeoff.
  
• Your Phantom climbed to 65 feet (above the takeoff point) before it started returning to the home point (the takeoff point).
  
• During the ascent to 65 feet, you hit the throttle stick a few times.
• Your Phantom crashed at 55 feet above the home point.

The Phantom manual notes the following in the RTH section:

"If you move the throttle stick after the aircraft rises above 65 feet (20m) but below the pre-set Failsafe RTH altitude, the aircraft will stop ascending and immediately return to the Home Point."

You hit the throttle stick about one second after your Phantom reached an altitude of 65 feet, but it appears your Phantom stopped ascending and started returning home as soon as it hit 65 feet. If the log is correct, I cannot explain why that happened. It should have continued to ascend until you hit the throttle stick one second later.

If you ignore that unexplainable event, your Phantom still would have been at an altitude of about 67 feet (assuming the same rate of climb) when you hit the throttle stick if it had continued to climb. That means it would have then started returning home at 67 feet and I'm assuming it would have crashed at that altitude as well. So, either way, your Phantom was doomed since you did not cancel RTH prior to the time your Phantom reached the point of impact.

FYI, when using the Smart Return-to-Home feature, DJI GO does display a prompt to allow you to cancel the auto RTH. If you don't see that prompt and/or do not cancel the RTH from that prompt within 10 seconds, your Phantom will start returning home. At that point, you can press the RTH button on your remote controller to cancel RTH.

Unbeliveable.... This man spent a great deal of time diagnosing the issue. Most have no idea how much time it takes to share this info.

I recommend anyone that crashes and plans to send their A/C to DJI to 1st have one of those known to research data look at what you have going on. And do the right thing and at least offer to compensate those that do this. The info details they provide can mean a great deal especially if you have been chosen to pull a fast one on by management at the repair facility.

Nice work msinger!

 

[Chris_P]

Agreed ... I truly appreciate the insight provided in this thread. I still have some issues with the altitude numbers but thanks to great analytics, it was a lesson learned in a number of other areas. Hopefully someone will benefit from this as I have from other posts in the past.

 

[MikeyOnline]

Well maybe you are using the same log viewing program as DJI but the one posted in the first response shows me this.... the path is no where near the trees. Its directly into the rock as I described. It seems different programs extract different fight paths? I'm not sure why the different flight paths .... I can assure you, it had no contact with any tree. It never flew near any tree. It flew directly into the rock then into the water. According to the logs, I was at 48' when it reported a motor obstructed error. It was already crashed at that point,

I agree that I don't see a tree from the satellite view where it crashed, but the log is unexplainable. At 16:22, the log shows it coming to a screaching halt while at 54 feet altitude and then dropping almost straight down for 1.7 seconds. I could believe the barometer is off but the Z axis velocity confirms that after the horizontal speed stopped, the accelerometer recorded a fall (near 1 G) for that same length of time, all the way until the last entry in the log. I can't explain how both the barometer and the Z-axis accelerometer recorded that it hit something while flying at 54 feet, you got a motor obstructed error, and then both the barometer and Z-axis velocity recorded that it fell at near the acceleration due to gravity for about 45 feet, until the log ended. Is it possible that during the last seconds of flight, a prop flew off or an ESC failed, causing it to drop quickly and impact the rock? The only way I can explain it is a prop flyoff or an ESC failure in the last couple seconds of flight. From your perspective (behind it), it might have looked like it just crashed into the rock but in reality, the log is suggesting that it DOVE into the rock. It's hard to dispute that in the last ~2 seconds of flight, it lost about 45 feet of altitude.

Edit: I should add that during that ~2 seconds of apparent loss of altitude, the yaw also indicated that it was spinning wildly, lending credence to the prop flyoff/ESC failure. I don't see anything else that could have caused it except an impact with something (maybe a small bird?). Isn't there a log that shows motor RPM? I thought I had seen one on here?

Mike

 

[Chris_P]

I agree.... Its unexplainable. Thats my issue. I watched the entire thing unfold in front of me and its abundantly clear that yes, I did try to regain control when the RTH was activated not realizing I would cancel the altitude climb but the fact still remains the drone was never at that altitude anyway. The altitude data was way off and that may have indeed contributed to the crash. Me friend recovered the drone seconds after on dropped into the water and the props were all in tact. there were chips and scuffs from hitting the rocks but they were still in place. Im glad for the GPS data because it shows accurately what happened, there were no trees anywhere the crash site.

 

[tytlyf]

That's what I saw too, the only strange thing standing out is the aerial map view not showing it going near the tree, but directly above the rock. I wonder how accurate the map is with the GPS coordinates compared to what the GPS is reporting in the bird. The trees look to be right around that 50-60ft limit. The oddity is the map not showing it near the trees.

 

[Chris_P]

The reality is when it came to the screeching halt as you describe it, it was only about 6-8 feet above the water. The reading of 54 feet was dead wrong. I was standing on the back of the boat in the picture I posted. I saw everything clearly. The drone flew directly from near the boat directly into the rock with very little change in altitude.

To answer your question Mike, I saw the spinning wildly part. After hitting the rock it did several cartwheels across the rock face before plunging in the lake. Thats what you are seeing.

 

[Chris_P]

Here are my props..... you can see they are all scratched and chipped from cartwheeling across the rock face ... if one spun off, it would be in tact. I took them all off and they were tight, no issue there.