Inspire crash into ocean. I'm clueless..

[Red_Raven]

- post here since this is the forum I use. Please help me read into logs

Ok guys it happened. I was just about reaching the bay where i stood at homepoint, batt at 14% when I simply watched inspire throw itself into the sea. It did not answer to me trying to ascend like it would if auto landing were happening.

It was an errorless flight from start
And everything seemed just fine
Dji go didn't show any errors not even at the moment it crashed.

So here I am left without a clue what happened. the log files I know how to access don't show me anything, the inspire is on the bottom of the ocean.
I called Dji in the United States and were told to contact Dji in Netherlands by email and I've already done so but not received any reply since this happened just tonight. how does the dji deal with such cases?

Do they ever take any responsibility themselves or do they try to put this on me?
Is there anyone here who can reach into those log files of mine and find out what really happened?
I would be really grateful if someone would give me some helping hand here.

Here's the airdata log :
Airdata UAV - Flight Data Analysis for Drones

 

[NCTurner]

Dang, I'm so sorry to hear about your Inspire! That had to really hurt to watch it go into the water like that.

I'm absolutely no expert on flight logs, but I did see 5 warnings for motor overload throughout the flight? Any idea what was causing that?

 

[Red_Raven]

Dang, I'm so sorry to hear about your Inspire! That had to really hurt to watch it go into the water like that.

I'm absolutely no expert on flight logs, but I did see 5 warnings for motor overload throughout the flight? Any idea what was causing that?

Since the latest firmware those warnings have become big part of all flights. And they're just a yellow once, and provide a solution to the problem. They say they'll slow things down and adjust properly to the overload. So it's not the problem I'm sure of.... Many pilots have talked about those being constantly blocking their screen [emoji848]

 

[Red_Raven]

Dang, I'm so sorry to hear about your Inspire! That had to really hurt to watch it go into the water like that.

It's my first unrepairable crash. Actually it's the second time I watch a uav drop into sea or water. It was a mavic the first time. Then it was completely my fault. But I managed to get it up from the bottom and flying again.

This time it's impossible without a professional divers. I was shooting videos of whales for a whale watching tourist company. And I've actually considered to call a diving service to get the sd card. It has some really good wildlife footage on it... I'm even thinking my best work ever.....
The whales acted like they knew they were being recorded, and showed their "guest tricks" it was awesome. Until this.

But really it wasn't so hard when it happened. My first reaction was a big "Hahh!" It's kinda like taking a punch it's not as bad as waiting for it.

But afterwards it's like naah, I can't do much about this except hope for dji to take the blame. So I'm not going to get bummed about it until I know they won't. It's not really a damage for me until then. [emoji23]

I'm trying to say, I tought it would be tougher to loose a uav than it happened to be. The hardest part is not having a clue of what happened and why.

 

[GerdS]

My thoughts when reading this:
The battery was at 14% and you was still above water. That was at least reckless!
I don't know the auto-landing safety level for Inspire, but assume it is at 10%, so there was little reserve in that battery. The Inspire is a quite old drone model and I assume that your battery is old, too. At least older than one year, maybe two.
An aging battery has an increased internal resistance and the capacity goes down. Also cell capacities may begin to differ. I am not sure how well this is reflected by the capacity value displayed in %, especially near the lower limit.
So I guess the battery voltage has fallen below a limit and the Inspire tried landing for safety.
This theory is also based on my own experience with one of my 3 years old Phantom 2 batteries. This battery has one weak cell, but still works for flying with caution. But if I discharge it for more than 25% the P2 will go into autolanding.

I say it again and again: LiPo batteries don't like to get deep-discharged. If you do this again and again, the life-cycle will go down dramatically. I have a golden rule for all my drones, landing at 30% capacity, with still some reserve if needed for landing. This way I can still fly with my Phantom 2 batteries after more than 100 cycles each and an age of 3 years.

 

[Keule]

Hi Red_Raven,
Sorry to hear the Inspire is lost.

It looks to me, that the battery had given up ...
- According to Airdata.com your battery health was 78%, hence the 'short' flight time of approx. 8:20 minutes.
(Not a good TB47 anymore)
- Battery cell 1 deviated in voltage over time nearly always compared to the remaining other 5 cells.
- At your way home the aircraft drew high Amps - > 30A. (multiple warnings: motor overload...)
As the battery was not the best anymore it reached the critical level very fast. -> I.e.: Warning: low voltage 20.273V
- I might be that the Inspire entered critical low battery level and landed at its current location.

I have no idea why you didn't received any message in GO app....

More detailed infos are in the raw .TXT log files in your phone/tablet. If you can share those we get more insight of what happened..

Regards,
K.

Edit: GerdS was faster ...

 

[Red_Raven]

Hi Red_Raven,
Sorry to hear the Inspire is lost.

It looks to me, that the battery had given up ...
- According to Airdata.com your battery health was 78%, hence the 'short' flight time of approx. 8:20 minutes.
(Not a good TB47 anymore)
- Battery cell 1 deviated in voltage over time nearly always compared to the remaining other 5 cells.
- At your way home the aircraft drew high Amps - > 30A. (multiple warnings: motor overload...)
As the battery was not the best anymore it reached the critical level very fast. -> I.e.: Warning: low voltage 20.273V
- I might be that the Inspire entered critical low battery level and landed at its current location.

I have no idea why you didn't received any message in GO app....

More detailed infos are in the raw .TXT log files in your phone/tablet. If you can share those we get more insight of what happened..

Regards,
K.

Edit: GerdS was faster ...

Thanks for your inputs guys. Im just surprised about no warnings and also being allowed to use unsafe battery and what so ever to fly it to the point it self destructs. The motor overloaded warning gas been on almost constantly for many pilots since latest update, and it even provides a solution by slowing down the quad to save point. But how am I than allowed to drain the battery to such critical level without those advertised as smart tools? That's what I'm surprised / pissed about. I shouldn't get trough this flight without even a tiny mention about unsafe battery?

I've been led to belive that as advertised as smart and safe, the system designed by same guys who chose battery and designed it's smart functions (that justify pricing more than 3x the price of similar lipos without the smart system) would safe me from driving the device into self destruct while using a flying mode designed by same smartasses.

Am I wrong to find this at least a bit stupit?

I thank God I was over water but not people or other folks possessions, so after this experience I find it more responsible to fly over water than over my town. It is actually done alot here since the regulations does not rule that out in my location.

For me it's just another case of Chinese business ethics. Advertising the product as smart, and safe to finish the process of selling the product, than it turns out that flying in one of three modes provided by the manufacturer it's not smarter than to not adjust things when they gets risky. No flying mode should allow such battery drainage if provided battery doesn't handle it. Not to mention that smart battery should for at very least warn it's user when it becomes unsafe to fly. And again.... Nothing that is smart woyld allow mode designed to function with that smart device to get to such critical point. Thats not smart, that's more on a retarded level of stupidity.


Do you know how I can reach those text files on ios?

 

[Red_Raven]

I'm more pissed about that i feel fooled by dji to have more belive in the quad safety functions than in reality I should.

I wouldn't pay 3-4x normal price for liposuction packages except I were made belive that it's advertised smart function would save me from loosing thousands of $ because it smart is actually quite stupit.

**** Chinese....

 

[Red_Raven]

I also have inspire 2 and a mavic. Should I be aware of any modes provided with them that could drive them into a unrepairable crash?

And isn't such knowledge something that should be either advertised or at least stated in manuals than how unbelievably smart this crap is?

 

[GerdS]

As I told before, stop flying your batteries to the limits!
Without looking into your log files I am quite sure you have got a battery warning before. In case of the Mavic the default setting for warning is at 30%, guess it is similar for Inspire.
Batteries are chemistry and their health depends on lot of external influences which cannot be sensed by protection electronics reliably, especially over a duration of years. So health of batteries is always suspect for surprises. That applies even to a Tesla car!

So your lessions to learn:
- Don't trust blindly into your batteries, especially old ones.
- Don't fly them empty, but try to land latest at 30% capacity.
- After landing, go into the battery settings of the GO app and check the individual cell voltages. If they differ for more than maybe 20mV this is a sign for weak cells. Then use this battery with even more caution!

For getting a better feeling on the health of old batteries it is also a good idea to sometimes (e.g. after each 10 flights) fly them down to e.g. 15% or until autolanding under controlled conditions, means hovering at low height over the landing place. So you will get a feeling for their limited reliability. In case of my P2 battery I found out its limit at about 25% this way.

 

[Keule]

Do you know how I can reach those text files on ios?

Connect your IOS device to a PC/Mac via USB
Open iTunes, enter your IOS device
goto Apps, then chose GO app, scroll all the way down, you should see the directory structure, then select 'flight records', copy them to your local drive on the PC/Mac.
That's it.

 

[Michael Ainsworth]

You can get a battery readout in the App.
Shows the various cell volts.

 

[GerdS]

I have now looked onto your battery data, too and this confirms my theory. Cell 1 is a weak one which was almost empty at the time of the last entry. This battery was ripe for disposal.

 

[Red_Raven]

I have now looked onto your battery data, too and this confirms my theory. Cell 1 is a weak one which was almost empty at the time of the last entry. This battery was ripe for disposal.

But still no one points that out... Shouldn't the app simply tell me that it's hazardous?

I'm just a photographer, not an electrician. therefore I trust in smart products. [emoji30]

 

[Red_Raven]

Sorry guys... I'm not pissed at you. If I sound frustrated it's because I feel like I was had for a fool by trusting on things not to be trusted blindly

 

[benjaminkan]

Sorry to hear about such a tragedy with the inspire. I don't think the manufacturers are at fault here. From most of the testimonials of crashed or lost mavic and/or other drones, they would suggest that flying out at 78% including having to fight against the winds out at sea might be quite risky.

I have considered adding some buoys or styrofoam balls when heading out for long and far distances over water.

 

[GerdS]

The intelligence of the app is limited, it is not artificial intelligence.
Maybe DJI could implement a warning based on the cell voltage variations as seen in your log. But as these variations are rarely consistent for all states of discharge and may occur just close to the discharge limit even such a warning might come too late for a safe return of the craft.

Belief me, reliable cell monitoring is a highly sofisticated job which is not perfect even at Boeing with their Dreamliner. So no reason to blame DJI for that.

 

[Red_Raven]

The intelligence of the app is limited, it is not artificial intelligence.
Maybe DJI could implement a warning based on the cell voltage variations as seen in your log. But as these variations are rarely consistent for all states of discharge and may occur just close to the discharge limit even such a warning might come too late for a safe return of the craft.

Belief me, reliable cell monitoring is a highly sofisticated job which is not perfect even at Boeing with their Dreamliner. So no reason to blame DJI for that.

I'm not necessarily blaming them for the crash, I'm well aware where my faults lay. But I'm only pointing out that clearly there is quite a gap between what dji likes customers to think of their products (what they advertise) and what information they should be providing us with. Not much of the battery I found you guys have posted here are available on the manuals not even going to mention the promotional materials.. Lol.

I'm lead to believe I've purchased a solid equipment that won't allow such obvious failures to happen like going to fast on an older battery will get me into serious trouble. And when I get into the trouble I'm kindly asked to go **** myself by their tech agents....

 

[GerdS]

I have sent a request to a DJI rep on RCGroups to add some code to the GO(4) app for checking cell balance during flight and throwing a warning and request for landing in case the cell voltages will differ as they did within your log file. Maybe they will add this, but still be aware that it won't be a 100% solution for crash prevention as this is just impossible.

 

[Red_Raven]

My batt got to almost boiling point. 70 degrees on Celsius. That's critical. And dji I go just didn't feel like pop up a friendly warning that day.... Thats malfunctioning software in my opinion.