My P3P crashed, DJI not cooperating

[henick]

To be perfectly honest, I don't think anyone in this thread is concerned with the height of your palm tree or whether or not DJI GO shows the height of your palm tree when your Phantom is at that altitude. After all, it's common knowledge that the altitude displayed in DJI GO is not 100% accurate. So, you're just going to prove that this common knowledge is accurate. But, carry on if you must

How far off is it to be expected? I don't want to be coming up to an expected 60ft high wooded area thinking I'm flying at ~120ft to misjudge and catch a treetop.

I normally leave a bit of buffer space but as I get more brave... Mine works fine now just about dead accurate.. there is a tower beside my house with 10ft increments marked. Mine is accurate inside a foot or 2 so much so that I always trusted it so far. Well. Until I hear enough stories like this to shake my confidence I guess.

 

[Chris_P]

My case to DJI will be as follows ... I have proven that the altitude reading of 54' on impact was dead wrong. The Phantom hit a rock that was no more than 5' in height. Thats a pretty significant error in one the most critical areas of flight - Altitude. For a device costing well over 1K, its reasonable to expect it to function properly in these key areas. That said, one thing is for sure ... If the altitude readings were correct, the Phantom would not have hit that rock. Period. We can speculate all day what may or may not have happened, hitting or not hitting other trees, less or no damage, more time to react possibly saving the AC etc.

There is also the less than perfect design of the RTH functionality which if it auto engages while the operator is applying negative throttle to land, the pre-set RTH is cancelled automatically and the AC flies off at whatever altitude it happened to be at. In this case there was a failsafe limit which was supposed to prevent flying off at low altitudes but that also failed due to the major error in the baro calculations. These were factors that directly contributed to the crash.

When I took the Phantom out today, I followed the suggested 3 minute warm up procedure. I noticed that the reported altitudes were fairly accurate at first, but after a few mins of flying around at various altitudes, I was seeing a deviation of up to 30 feet. I'm sorry DJI, this is unacceptable. I have learned a lot going through this experience, hopefully it will prevent others from having similar issues and possibly result in some modifications to the programming of the RTH functionality.

 

[snerd]

To get 30% off, I'd ask for 50% at first. Leave some wiggle room!

 

[impilot51]

Shall we start a pool as to DJI's response? Good argument BTW, and I feel your pain. My bet though is they will stick at their current offer, with the retort that simply disabling RTH in the case of being on a boat would have been the prudent thing to do. That, coupled with this statement in the manual "if you move the throttle stick after the aircraft reset above 65 feet (20m) bet below the preset Failsafe RTH altitude, the aircraft will stop ascending and immediately return to the Home Point" in conjunction with the flight log showing throttle input after 65 feet indicated. They will probably say there will always be some error in a barometric instrument, blah blah blah, but if you had either not enabled RTH or not given it throttle input, you would have not crashed. Now, that is probably a fallacy, as the altitude error coupled with trees later on would have just meant a crash somewhere else. The real answer here is that RTH should not have been used in this situation. If you had not done that, altitude error would not have been an issue, and therefore it would not have crashed. Let us know what they say though. Maybe the real brains here can come up with a good argument to their argument.

 

[Noodle]

My bet though is they will stick at their current offer

Same here.

 

[GadgetGuy]

To get 30% off, I'd ask for 50% at first. Leave some wiggle room!

I'd insist on first getting a different manager involved on the phone, one who really wants to help, and start at a full replacement under a manufacturing defect in the barometer and a dumb Smart Return Home function. If you reach the right person, you will prevail.

 

[Luap]

How accurate is VPS over water though?

There are three sensors - 2 ultrasonic sensors and a monocular camera.
Obviously the monocular camera will not be able to track any points over water -So VPS will not work or not properly.

However the utrasonic sensors will measure altitude to around 3 meters and shouldn't be affected by water too much. And those values are in the txt logs converted with @ferraript converter or @BudWalker converter. Furthermore the crash happened above rocks not water.
So I had a look at both the Dat log and the TXT log. The two graphs in blue come from the TXT log all the other data from the Dat.
There are two values in the Blue chart showing VPS Altitude. One is coming fromOSD.sWaveHeight [m] - the yellow line and the other is OSD.isSwaveWork the green line.
Right before the crash OSD.isSwaveWork is True and OSD.sWaveHeight [m] indicates an altitude of 1.9m above the rock. At that moment Phantom is flying forward . The front motors are the first to indicate load increase. This indicates it flew forwards into rocks that were at least 1.9meters higher.
The txt log also indcates that a 6 minute video was recorded. I haven't read through the whole thread but did the OP post it? Would be interesting to compare visual heights with logged heights.
Here is the video of the last seconds right up to the crash and slowed down 4x.

 

[msinger]

OSD.sWaveHeight [m] indicates an altitude of 1.9m above the rock

Any idea why the altitude was so far off?

The txt log also indcates that a 6 minute video was recorded. I haven't read through the whole thread but did the OP post it?

No.

 

[Chris_P]

The video wasn't running at the time of the crash. If the video from earlier will assist I can certainly post it.

 

[flyNfrank]

How far off is it to be expected? I don't want to be coming up to an expected 60ft high wooded area thinking I'm flying at ~120ft to misjudge and catch a treetop.

I normally leave a bit of buffer space but as I get more brave... Mine works fine now just about dead accurate.. there is a tower beside my house with 10ft increments marked. Mine is accurate inside a foot or 2 so much so that I always trusted it so far. Well. Until I hear enough stories like this to shake my confidence I guess.

This barometer subject should probably have it's own thread instead of continuing deep in this thread.

It is actually important that you observe your altitude reading before and after launch, sometime during flight, and before landing. I have a habit that stuck with me from flying the P2V in which I also launch and hover around 100ft to observe both the altitude reading as well as hovering characteristics. I'm watching to see if the A/C is staying put, or if it drifting from the point in which it 1st came to a stop at. Then before continuing on I check the altitude reading to see if it is at least close to the point I know to be 100ft. And from past experiences with the P2V+ if the altitude reading was off at the point I mentioned, it will be off during other parts of the flight. Because of pressure change, the barometer does change the reading, but I have no idea how accurate the readings are because by the eye I could tell the difference from 270ft to 310ft. I would just know that the A/C is well above 100ft.

Also, most don't know this, but barometer changes to the altitude reading can not be trusted if landing at a high rate of speed. Have you ever brought your A/C down and suddenly release the sticks to stop the A/C only to see it Pogo up and down for a short time? That situation happens due to the barometer not able to adjust soon enough based on pressure changes.

 

[Chris_P]

I haven't read through the whole thread but did the OP post it?

Here is a link to the video shot earlier before the crash

Dropbox - DJI_0222.MOV

 

[pe9999]

Firmware is like software the developer does not bear any responsibility if the user does not know how it work. In your case, it seems to me you didn't know the rth procedure nor manual control the vehicle. I know it is dji marketing made people believe that it takes no training to fly it, you are just learned the truth.

Thank you all for the comprehensive analysis of this incident. I truly appreciate the insight offered. I do have a few questions ....

1. Im happy there is a record of my pre-set RTH altitude. I was worried that it got reset or erased when I updated the DJI GO app. That said, I don't understand the reasoning behind throttle input cancelling the altitude rise and triggering a RTH at a lower altitude. To be honest, everything happened so quickly, I had no idea that RTH had engaged, I thought there was some interference that caused me to lose control. The throttle inputs were my attempts to regain control of the craft once the RTH commenced.

I don't understand how DJI calculates altitude, there is no way that rock facing where it crashed is 65 feet. It crashed maybe 5-6' above the water then fell in the water. I have attached a pic taken by the drone just before the crash. The picture shows the exact rock area where it crashed. I was standing on the swim platform of the boat bringing it in then it took off and smashed into the rock directly across from the boat.

2. Considering these circumstances, is 20% off a new P3P a reasonable offer from DJI? I truly think that these unfortunate circumstances could have been prevented if the drone rose to my 30M height I would at least have had time to realize what was happening and cancel the RTH and regain control of my craft. Looking at the picture, I can assure you there wasn't any noticeable rise in altitude. It just appeared to me to fly directly across and hit the rock. I would expect DJI to take some responsibility and do a little better than their current offer.... Has anyone had them reconsider a "final offer"?

 

[MikeyOnline]

At 6:06 into the video, I grabbed the attached frame. Based on the Carver 396 beam width (14 feet) and the P3P's 94 degree camera field of view, I calculate your distance from the center of the boat as 55 feet at this point. That would make your altitude less than 55 feet (max of probably 50 ft altitude at that point, being conservative). Curious what point that is in the log and what the logged altitude was at that point and how far into your flight you were when that video was taken. We've already established the altitude was off, so I'm not beating that dead horse. Just curious if this was shot earlier in the flight, if we could establish how much or how fast the altitude was drifting during flight?

Mike

 

[henick]

DJI is well aware of the cheap barometer vendor they tried to get away with in the p4 and they are paying for that decision now. For $1800 I expect decent quality materials. Just like I don't expect a plastic Lexus. At least carve the important parts out of wood guys jeez. They should know better imo and the only way they will learn that lesson is if taken to task when something fails.

 

[Jeiel Shamblee]

Been there in a way. DJI does not usually tell you what the malfunction was. Their communication is improving, but it's not good. I bought a P3P at the same time (October 2015) and less than 3 months later around 130 flights it crashed because something failed.
Initially DJI told me "non warranty repair..." pilot error. I was able to prove from the logs that it wasn't pilot error and after a few days they said it would be covered under warranty.
No information about what went wrong. There's a lot more to the story, including having to send it back a second time and having to contact the BBB.
The short version is that DJI does seem to have good intentions, but their communication is very bad.
Don't give up. If you are right and can prove it, you will be able to get some kind of resolution. Sadly, it may take a lot of work.

 

[Fantasmagorico]

DJI has the worst customer service of any commercial entity I have ever dealt with. And it's not just addressing issues such as yours, just getting answers to basic questions like upgrading the firmware is like pulling teeth. In part, I think the people who handle these matters haven't mastered English, but it goes beyond language skills.

I also had a loss of control incident resulting in my P3P falling into Biscayne Bay near my house in Miami Beach, where the current probably took it to the Atlantic ocean. Here is brief version of what happened. About half a mile from the Home Point in a huge and empty parking lot, I lost the signal. A few seconds later, the bird started an automatic return to home and I lost sight of it because of background clouds as it rose to the failsafe altitude of 400 feet. Eventually I received a warning on my device that the aircraft was descending. I expected to find it above my head, but instead it was about to land about 100 yards away in the middle of a busy intersection. I canceled RTH and took control manually, but the bird would not come towards me. I could make it fly in an arc, as if it were in Home Lock mode, but not toward the HP. It was as if there were an invisible barrier that it wouldn't cross. I struggled and tried everything, but it simply refused to approach until the battery ran out and it dropped in the water.

I requested a replacement from DJI (my bird was less than five months old) and provided the flight logs as well as data from Healthy Drones, which showed no user error whatsoever. DJI refused, insisting it was user error because I had continued to fly the drone until the battery ran out. Imagine that logic! Of course I continued to fly the drone until the battery ran out; I was trying to bring it home. DJI completely ignored the fact that, inexplicably, the bird just refused to approach the Home Point, and could not provide any evidence of pilot error. DJI also offered me a 15% discount on a new one. I refused; then it offered 20% as a final offer. In the meantime, I filed a protest with Paypal, which said it couldn't make a decision and we had to resolve it on our own. As I am a lawyer and was furious with DJI, I considered filing a class action lawsuit, since incidents such as these are common. But I decided it wasn't worth it and reluctantly took the offer. I looked at other options, such as Yuneec, but wasn't convinced they would be any better. Good luck in your dealings with DJI.

 

[Azmopic]

Hummm

 

[mitshko]

Hello everyone,
I've been reading and learning on this forum since I purchased my P3P in November 2015. I hoped to never have to post this message but here I go ....

I put about 50 flights on my bird, all of them went perfectly. Ive read and followed all the suggestions shared on this forum and I fly very carefully. I read many posts about RTH crashes and I set my RTH altitude to 50M to avoid issues in this area.

3 weeks ago, I was up north on my friends boat filming some ariel shots. i was riding in the boat with the P3P flying above us. We started in one area and drove approximately 1.5 km. As we moved along, I periodically updated my RTH location. We turned around within this bay and I was bringing her in for landing, usually I have her hover and I grab the landing gear while shutting the motors down. As I brought her in, she was about 40 from me at an altitude of appox 15 feet. Suddenly, the drone just flew off at full speed away from me, crossed the bay and smashed into a rock before falling into the water. The camera was smashed right off the bottom and three props broken. Luckily my friend and his family were standing near that rock and recovered it within seconds of it falling in the water. It was fully submerged for a few seconds however.

I was totally perplexed as to what happened as I totally lost control and had no user input when it took off and crashed. I reviewed the logs on my iPad and then it was clear what happened. Apparently, my RTH location wasn't updated properly and my battery was at the point where I just had enough power to return to the perceived incorrect RTH location (1km away). Evidently this triggered an auto RTH sequence that took control away from me, flying the drone into the rock which stood between my location and the RTH point.

The other crazy part is I had previously set my RTH altitude to 50M. This didn't happen.... when the auto RTH started, it just flew off at the same landing altitude without rising to 50M as I had initially programmed.

I went through the whole DJI warranty procedure, they took over 2 weeks to review my flight logs and eventually said, they would like to assist me by offering me 15% off a new P3P !!!! I responded saying that it was a malfunction in their software that caused the crash and they just responded yesterday saying they will offer 20% off a new P3P and thats their final offer. They didn't explain what their 2 week investigation revealed or what their position was regarding the reason for the crash. I find this totally unacceptable.

I mentioned to the customer service rep when I called that it was very lucky that this happened in a rural area away from people. An auto RTH like this happening within a populated area could cause serious injury or damage to property ! They need to address this by a dialog box confirming RTH requiring the user to press OK before initiating the RTH. I still have no idea why it ignored my setting of 50M for the RTH altitude.

If anyone has any thoughts or advice in dealing with DJI I would be very happy to hear it. I plan to call them again on Monday to argue this further.

They don't speak proper english (DJI) or they are not interested in giving a good support. My drone took many weeks to be repaired because I didn't wanted to pay before I receive the answers of the questions I was asking by email, but they will not understand and answered me other things. The emails trend to bounce and this made communications very slow, something goes wrong with their server once in a while.
I gave up and ended paying the amount just to receive the bird as fast as possible. I am not sure if the drone needed the repair they said, for me was something much more simple to repair.
They made me a discount of 2% (two percent), but I after I had paid the full amount of the repair, so when I asked for the refund of the difference I was offered spare propellers. I refused given I have already many spare propellers, so then, while they take their time to answer the emails... the drone appeared at my door with the new propellers. They said sorry by email, they already sent because they don't have other spare parts (even they asked me before if I want the propellers).
Never more DJI, I will find and alternative company that can do any the maintenance.

 

[Chris_P]

We've already established the altitude was off, so I'm not beating that dead horse. Just curious if this was shot earlier in the flight, if we could establish how much or how fast the altitude was drifting during flight?

Ive looked at the file creation times of the video and the photos taken just prior to me landing the Phantom. the video started at 12:36PM, so six minutes in would be around 12:41PM. The last picture I tool before bringing it in was at 12:51. It appears I did a video first then took a series of pictures from 12:43 to 12:51 then brought her in to land.

 

[Don Wilson]

I agree ... there are ALWAYS freeky things that can happen, but you can ALWAYS cancel the RTH function and manually override and land the aircraft. I test my RTH every now and then to make sure it is working, and cancel as soon as I can see the aircraft as the GPS is not dead on and it will land in my pool if you let it land on it's own. Also .. if you were following the boat, why not use the "Follow Me" function that AUTOMATICALLY updates the home point? When I am in the boat, I always use the "Follow Me" function to update the home point. But even then, I don't really trust that I am in the exact same spot.