DJI Phantom 3 took a little swim

[austincwelch]

Hi Folks,

My name is Austin Welch and I am new to the forum here, but I am looking for a little help.

Yesterday, I took my aircraft off for a flight on an island near Alexandria Bay, New York. It was my third flight of the day and I’d had no issues previously. After installing a fresh battery, I set my home point for the beach area of the island, and took off. As the aircraft was climbing through about 95 feet AGL, I experienced a lost link notification with the aircraft. I continued to have live image streaming (still well within line of sight) and after after 10 seconds, the aircraft returned to a “connected” state. As soon as it reconnected, a new home point was displayed (over the water) approximately 100m from my position even though it was over land when it lost link. The aircraft then displayed an “out of range” message immediately following the reconnection (was only about 30m lateral distance from me at this point) and indicated the return to home auto land function had been initiated. Given that the aircraft was already over it’s new home point, it began a descent from its position. Over the next minute, I attempted to cancel the auto land sequence over 15 times but each time, an error message was returned. Despite application of the left stick to increase altitude, the aircraft did not register my commands nor did it enable me to change flight modes. I watched, with about 20 other people on the beach, as the aircraft continued its descent from 95 Feet slowly downwards before it entered the water. I continued to have live video of the event until the aircraft was completely submerged and promptly sank at which point the altimeter registered -15.2 feet before becoming disconnected once again to my horror from the beach. We were on the beach preceding a military ball so I had no ability to jump in the water in my full uniform. Approximately 3 minutes after the drone landed, we had a boat in the area which was unable to locate the aircraft. The next morning, we also went diving and attempted to recover the aircraft but the depth right next to the island is about 75 feet due to a deep cliff underwater and we couldn't reach it. The only data I have to go off of is the warnings within the app which were recorded including the attempts to cancel the landing.

I am a dual-rated commercial pilot in both fixed wing and rotary wing aircraft. I also have hundreds of hours flying drones so I am not by any means an inexperienced pilot. Never in my experience have I witnessed anything like this. This particular drone was purchased refurbished from DJI approximately a week ago, so essentially it was brand new. I have a significant amount of flight time using DJI products as well and have never observed anything like this event. I do not know whether or not this was merely a glitch or an issue with the aircraft itself, but the inability to terminate the auto-land sequence and the movement of the home point as the drone reconnected are directly (and solely) responsible for this incident.

I sent a note to DJI support which I hope will be answered when they're back into work tomorrow morning, but I just wanted to pick some brains on the forum to see if anyone had ever heard of anything like this happening?

 

[Fly Dawg]

If you would like an idea as to what occurred, upload you flight data to the link below. There are many here that can and will analyze the data and see if any anomalies can be determined as to the cause. Be sure and post a link back here so others can review.

DJI Flight Log Viewer

 

[austincwelch]

Hey Fly Dawg, thanks. Had not utilized this tool before. wow! This is pretty crazy. The crash point is accurate.... this follows just about exactly where I thought it landed. However, the flightpath and other information do not appear accurate at all. There were not aggressive lateral deviations during the flight as displayed herein.

DJI Flight Log Viewer - PhantomHelp.com

 

[Fly Dawg]

Just a quick glance through, according to the data file the home point never changed from the original takeoff location. As to why it created a new home point and that point does not reflect in the data, I can't answer.

 

[austincwelch]

The takeoff point was about 10m east of where any of the flightpath shows. I was on the point just northwest of the northernmost house when I took off. There is no flightpath shown from the land to the landing point which is where the confusion lies. Thats why my assumption is that it created a new home point. When it showed a home point over the water, I attempted to reset it, but in the log it indicates it "didnt record" the home point.

 

[Fly Dawg]

Now I think I can answer, the home point at the beginning of the flight log, the takeoff location was here. It appears that the original point was not reflected in the data for some reason.

 

[austincwelch]

Also, the real question is that when it acknowledged the landing cancellation (which it does several times) and the left stick was applied "full up" why it continued its descent?

 

[macoman]

You never saw any compass error on the screen?

 

[austincwelch]

Never... nor was there request calibration before takeoff

 

[WV. Rootman]

So what was the obstacle it was trying to avoid at 96.5 ft?

 

[austincwelch]

Nothing! that's what is crazy! There was wide-open space up there and i couldnt climb higher than 95 either...

 

[Fly Dawg]

Next question, did you verify the "takeoff" location per the on screen maps were accurate for your takeoff point? The data does not reflect that. But if you did, you would have noticed the location was over water and should have not taken off. That is neither here nor there at this point, but that would have been a clue that something was amiss from the start. As for the other issues, it appears to me that something was very wrong before the flight even began, assuming the data is accurate. I feel for your loss, and it does not appear to be OP error in what I can see other than the original home point, assuming you verified that prior to takeoff.

 

[austincwelch]

It limited me at 95 and wouldnt enable me to climb higher. Instead of the normal 400, it stopped climbing at 95 and indicated the max alt was reached.

 

[mdowney58]

Not sure, but I believe that you need to also upload the flight record from right before the final one.
I think that I've read here before, that when the connection is lost between the R/C and the A/C, that the flight after reconnection becomes a second flight

 

[austincwelch]

Next question, did you verify the "takeoff" location per the on screen maps were accurate for your takeoff point? The data does not reflect that. But if you did, you would have noticed the location was over water and should have not taken off. That is neither here nor there at this point, but that would have been a clue that something was amiss from the start. As for the other issues, it appears to me that something was very wrong before the flight even began, assuming the data is accurate. I feel for your loss, and it does not appear to be OP error in what I can see other than the original home point, assuming you verified that prior to takeoff.

I did double check it before I took off..... and it showed me right where I was which is why I suspected the home point had moved.... also, why, if any reason at all, would it have showed max distance reached when it was only 160 ish feet form the home point?! Whether it was on the island or 10m into the water as it indicates.

 

[Fly Dawg]

It limited me at 95 and wouldnt enable me to climb higher. Instead of the normal 400, it stopped climbing at 95 and indicated the max alt was reached.

That is the new app issue. Many threads about that, but you have to log in to lift the altitude and distance restrictions.

 

[austincwelch]

That is the new app issue. Many threads about that, but you have to log in to lift the altitude and distance restrictions.

But the two previous flights that day went to 400 no problem and were in a very location (give or take 400m laterally)

 

[Fly Dawg]

But the two previous flights that day went to 400 no problem and were in a very location (give or take 400m laterally)

Coincidental, maybe. But if the GO app was updated in between that time, it would impose the altitude and distance restrictions if you did not log in to DJI before that last flight. That's stretching it a bit I know, but the numbers you are giving are near exact to the flight restriction numbers.

 

[Fly Dawg]

By the way, could you provide the AC model? You never specified. Also the device, OS, App version, AC firmware and RC firmware. That helps too sometimes.

 

[austincwelch]

By the way, could you provide the AC model? You never specified. Also the device, OS, App version, AC firmware and RC firmware. That helps too sometimes.

Fly Dawg, it's a P3 standard operating IOS. Additionally, the only firmware update was applied before I ever took my first flight out of the box... so i've only ever flown this aircraft with that latest update. The morning flights enabled me to climb to 400 feet without issue and laterally I flew probably at least 750m from the home point/controller. There were NO changes in-between the morning flight and the afternoon (the incident) flight... that flight allowed for about 160ft lateral seperation (as indicated in the logs) before indicating "out of range" while still remaining positively connected to the controller. Additionally, the altitude topped off at 95ft even before the out of range message was displayed. I adjusted no settings or anything like that. Solely charged the battery between the flights and took off.