Evo Lost

[Barney]

august 23 while flying in lubricious mode and 900 meters from home point comms were lost, the fail-safe option as stated in manual did not operate
50% drone battery 93% controller battery, height 14 meters flying over water , have flown over the same body of water 47 times
flight log shows drone came to a hover just prior to losing comms. what happened to the drone next I have no idea
as I am in australia autel USA tell me there is nothing much they can do

 

[Ansia]

Can you post a video from the flight logs?

 

[Barney]

august 23 while flying in lubricious mode and 900 meters from home point comms were lost, the fail-safe option as stated in manual did not operate
50% drone battery 93% controller battery, height 14 meters flying over water , have flown over the same body of water 47 times
flight log shows drone came to a hover just prior to losing comms. what happened to the drone next I have no idea
as I am in australia autel USA tell me there is nothing much they can do

Can you post a video from the flight logs?

what format does this site allow
tried mov and mp4 doesn't like those

 

[Ansia]

what format does this site allow
tried mov and mp4 doesn't like those

You will have to upload your video to a streaming service like youtube, vimeo, a cloud storage like dropbox, google drive, onedrive; and post a link to it here.

 

[Barney]

Dropbox - File Deleted - Simplify your life

www.dropbox.com

note at 00:05:11 all commands to air craft were removed, 3 seconds prior to loss of comms to controller

 

[Ansia]

After watching the video and verifying location, possible obstacles, etc on the map. I know for a fact you did not collide with a man made object. So here are a few questions.

How long was it from the point it stopped responding, until you lost connection?

Were you looking at your screen? Did you have video feed or did it become a still of the last transmission in a black & white view?

How was the wind when this happened?

Did you witness any bird flying in the vicinity?

My theory is either a gust of wind or bird strike.

 

[Barney]

it was only seconds from point of control to loss of connection
i was looking at screen with colour video, then controller screen comes up with connecting like it does when you first power up
max wind that day was 5Km
that area has minimal bird activity
but yes maybe who knows if it contacted a bird !
if a bird flew into it whilst hovering would that bring it down

 

[Ansia]

it was only seconds from point of control to loss of connection
i was looking at screen with colour video, then controller screen comes up with connecting like it does when you first power up
max wind that day was 5Km
that area has minimal bird activity
but yes maybe who knows if it contacted a bird !
if a bird flew into it whilst hovering would that bring it down

Yes. The motors are designed to turn off upon impact of a hard surface or if it flips for more than 90°. This is why I believe a big bird, like a hawk, attacked it.

It is sad that the Evo does not create a log file with detail information like other brands do. If they did I could tell you the status of each motor up to the point of disconnection narrowing down the possibilities.

What exacly did Autel tell you? I was under the impression they had representation in Australia.

 

[Barney]

something happened between autel aus and autel usa in august
autel tells me they have no authorized representative now in australia, how ever the au autel site is still up and running

the support guy in autel usa thinks i flew the drone into the water

 

[Ansia]

something happened between autel aus and autel usa in august
autel tells me they have no authorized representative now in australia, how ever the au autel site is still up and running

the support guy in autel usa thinks i flew the drone into the water

Send them the video you showed me. It will prove you never crashed it. I know Autel once replaced a lost drone to one of our members.

 

[Trox]

My suggestion since you live in an area of such clear water and you can pretty much pinpoint the search area in more or less a 50 meter radius based on GPS coords and the map view, get your dive buddies out there right away and run a search pattern. Doesn't appear to be very deep water either and that submerged structure is a key element to establish a reference point. If you can find the drone you can retrieve the "Black Box", i.e. the SD card and review the onboard video recording to see just what may have brought the bird down. The SD chips are waterproof so if you can find that data the mystery could be solved or at least eliminate a solid object collision as the reason.

The rapid descending of altitude during the last few seconds....were you causing that from your controls by deliberately dropping altitude? Or were you flying at a constant altitude for the leg back home? At that angle and speed of descent it almost appears it took a nose dive. Perhaps a blade failure which would be fatal and would be evidence if you find the drone and recover the chip.

[EDIT:] Just converted your 19.4m/s to mph...you were doing 43 miles per hour and at a steep angle of attack on descent at that speed and only 14m above sea level your drone would travel that 14 vertical meters in less than one second straight down. Put the bird on a descent path of even 45° and it would only take one second to cover that distance to the water. I can fine tune my ball park figures here using the coordinates for actual travel distance tied to altitude change. But it seems to be a kamikaze dive.

Well hell, while I am on the theoretical possibilities, at 43 miles per hour and a steep dive and maybe against a buffeting headwind I suspect in a rare but not impossible event one of your front two motor arms folded to the rear and brought the bird down. The arms may have reached their "break point" in wind resistance and one or both folded. But recovering the drone would not verify this was the true cause since the impact with the water most likely would fold the arms at that time.

I am a diver and always have 3 tanks of air in the garage. I guess since I too will be frequently filming activities along and over lakes, rivers, and ocean that equipment may come in handy for my own needs some day. I hope not.

 

[Ansia]

My suggestion since you live in an area of such clear water and you can pretty much pinpoint the search area in more or less a 50 meter radius based on GPS coords and the map view, get your dive buddies out there right away and run a search pattern. Doesn't appear to be very deep water either and that submerged structure is a key element to establish a reference point. If you can find the drone you can retrieve the "Black Box", i.e. the SD card and review the onboard video recording to see just what may have brought the bird down. The SD chips are waterproof so if you can find that data the mystery could be solved or at least eliminate a solid object collision as the reason.

The rapid descending of altitude during the last few seconds....were you causing that from your controls by deliberately dropping altitude? Or were you flying at a constant altitude for the leg back home? At that angle and speed of descent it almost appears it took a nose dive. Perhaps a blade failure which would be fatal and would be evidence if you find the drone and recover the chip.

[EDIT:] Just converted your 19.4m/s to mph...you were doing 43 miles per hour and at a steep angle of attack on descent at that speed and only 14m above sea level your drone would travel that 14 vertical meters in less than one second straight down. Put the bird on a descent path of even 45° and it would only take one second to cover that distance to the water. I can fine tune my ball park figures here using the coordinates for actual travel distance tied to altitude change. But it seems to be a kamikaze dive.

Well hell, while I am on the theoretical possibilities, at 43 miles per hour and a steep dive and maybe against a buffeting headwind I suspect in a rare but not impossible event one of your front two motor arms folded to the rear and brought the bird down. The arms may have reached their "break point" in wind resistance and one or both folded. But recovering the drone would not verify this was the true cause since the impact with the water most likely would fold the arms at that time.

I am a diver and always have 3 tanks of air in the garage. I guess since I too will be frequently filming activities along and over lakes, rivers, and ocean that equipment may come in handy for my own needs some day. I hope not.

I see some flaws in your posts. Yes, he was going at 43mph, but in ludicrous mode, you lose 2 ft per second. 15m is 50', so it would take him 25 seconds to crash. His bird disconnected in less than 10 seconds. So pilot error could not be the cause of this crash.

As for the arms folding. I've flown at 30mph+ winds with my Evo and it didn't close the arms. For them to break their lock and close up, would take a lot of beating. I've never crashed my Evo, but I am a rough flyer. It still doesn't show any signs of wear and tear.

 

[Trox]

Thanks Ansia for your additional input and contribution to the analysis. I always love a good mystery and this one continues to provide new discoveries.

I assumed (based on the map image) that the aircraft went down in the ocean off the beach but actually it went down in a lake. There is a sub-sea structure below the surface (almost like a sunken pier) as the map shows and there is a permanent float of some sort just off the end of the underwater structure. And at 5:14 on the last reported data point it was still flying at 19.4m/s and about 109 meters from the floating platform. I suspect this is a man-made lake with an earthen dam and the sub-sea structure is a sequence of water intake pipes for drawing water at various levels as the lake may fluctuate. But I digress. LOL [BTW, freshwater lakes can be notorious for having aquatic vegetation growing on the lake bottom and the idea of a scuba search and rescue mission may be fruitless. In addition if this is actually a city drinking water supply there is probably no swimming or boating on it as is the case for a lot of municipal water supplies. There is a large water processing facility of some sort near the lake on the canal.]

I ran a vector analysis of the flight path from the highest altitude of 42.4 meters on the return leg to the last known altitude of 14.2 meters over a distance of 867 meters, or a little over a half mile measured on Google Earth by coords. Based on that calculation the angle of descent was only a 2 degree slope and not near as steep as I assumed before crunching the numbers. And indeed perhaps that decrease in altitude at full ludicrous throttle was the result of the aerodynamics of the angle of attack of the drone as noted by Autel in one of their ludicrous cautions. But as you noted Ansia, projecting that continuous loss of altitude at full throttle would have carried the drone another 428 meters before impact. That would have put the drone about half way back to launch point from last known location but still a quarter mile offshore. I got a 22 second continuation before impact so we are both juggling the same apples.

It is still unknown what the condition of the aircraft was as far as wear and tear and possible weak structural components. Flying at full ludicrous throttle is definitely putting the aircraft in its maximum external stresses situation. A hidden defect in a prop under these conditions could have resulted in a failure of the component. Or perhaps a sudden motor seizure at max rpms. Anything rotating has a mean time before failure rating which is just an average of early failures and later failures. Like hard drives.

But there are still a couple of mysteries. The screen display of the software does not resemble the current configuration of flight and control telemetry that the latest software displays. ?? Was this an outdated firmware version? Or is that an iOS version? Primitive if so.

Watching the GPS indicator the aircraft was always seeing 15-17 satellites. However there is nothing on the screen similar to the latest firmware display showing Remote Control Signal Strength and Image Transmission Signal Strength. Next to the GPS satellite indicator is a signal bar graph representing something. And note that during the entire flight there is frequently Zero Bars showing on that graph. If this represents what the drone is sending to the RC then there was a developing loss of communication from the drone. If this bar graph represents the signal from the RC to the bird it would indicate the RC transmitter was failing. Perhaps those of you who have had the EVO from the earlier days of the software can clarify the Bar graph next to the GPS satellites indicator and what signal that represents in the old days.

What I don't understand is if the RC/drone communication link was lost why didn't the craft go into fail safe and return home. Unless this old software version has a bug, or pre-dated safe guards that were added in later versions. So it does support the possibility of a component failure on the aircraft as one valid scenario. I've not seen any live birds on the satellite images of this lake over many years of images so I'm ruling out a bird collision but perhaps not a bird attack as a long shot. But that hawk/eagle/falcon would have to fly much faster than 43mph in order to catch up with the drone. Rule out hawk and eagle. That leaves a Peregrine falcon which I believe do exist down under. But this would be an unusual place for that bird to be since they prefer mountains and coastal cliffs.

As I said, I just love a good mystery. It's been raining for two days straight so I've been grounded.

 

[Jagerbomb52]

I believe this is what your looking at. Just doing a simple search on the coordinates in google gave me this picture. Seems to be a lot of steal in that structure. Not saying this has anything to do with it gettting lost but sometimes it can affect the compass. I have flown by steel bridges and have had compass warnings in the past.

 

[Jagerbomb52]

If you google maps street view of the location it tells you a lot about where he was flying.

 

[Trox]

I believe this is what your looking at. Just doing a simple search on the coordinates in google gave me this picture. Seems to be a lot of steal in that structure. Not saying this has anything to do with it getting lost but sometimes it can affect the compass. I have flown by steel bridges and have had compass warnings in the past.

Actually that intake structure is over in the corner of the lake photo below. And coincidentally that is where the pilot was flying from so I wonder if there was a chance of interference at the pilot location. You can see the UW objects I was referring to near the last drone location marker. And the floating platform I mentioned.

Based on the common knowledge that lots of metal things can raise havoc with a drone in flight, I wonder if those UW pipes could create some interference even though they are beneath the surface. Photo #2 closeup. That does present yet ANOTHER variable in this mystery....coincidence or "the smoking gun." LOL Or perhaps an alien space craft hiding beneath the water.

BTW, I was flying my EVO in the area next to a livestock containment area which was surrounded by an electric fence for the cattle. I was practicing dual joystick control flying by moving forward at a modest speed and rising in altitude smoothly at the same time. Several times it was as if I had hit an invisible wall, the drone just slammed on the brakes and jerked up. Flying the same method much slower in speed and altitude change OR going pedal to the metal all out did not produce that result. But returning to a modest speed and altitude rise resulted in a repeat of the reaction. I need to try those moves in a different location and then back at the rodeo grounds to see if it may have been an electromagnetic field emitted from the fence or something to do with the joysticks' specific positioning.

 

[Ansia]

The only way the drone would not implement RTH upon signal lost would be if it wasn't in the air anymore. That is why I believe a bird strike is possible. This lake isn't large enough for an eagle to fly through. I did like your analisys of speeds, but eagles can attack from the front or sides too.

The only other possibility is if you lost gps and signal, making the drone autoland on the spot, but that is a perfect storm.

This scenario reminds me of what happened to @macoman's drone. He also lost it while photographing a steel ship, over water.

This is a screenshot from a flight log of mine. I am in the latest beta firmware of Android.


Looks identical to OP's video. No idea what the bars are for.

 

[Barney]

excellent comments guys
this reservoir at prospect west of sydney is part of sydneys drinking water network and access is restricted to the public
other wise i would be out there in a boat trying to locate my 4 month old evo
and yes if I could get that sim card that would reveal what happened !
the underwater structure shown of google earth is a pipe system that pumps compressed air up through the water, why they do this i am not sure but all our dams in the state have
this same system and i am not sure if the pipes are steel or some form of rubber or what ever

Aliens must have taken it !!!!!!!

 

[Barney]

also autel have the flight log I have posted on this site, their latest comment.


So after continuing to look at this, I believe that your drone might have struck something mid air. Without the drone anymore, we would not be able to confirm this with the internal flight logs.

What makes this tricky is that you are Australian based and we do not currently have repair service support in Australia, so our support options are somewhat limited. I would be more than happy to speak with my supervisor to see if there is anything that we can do for you at this time.

 

[Ansia]

Hopefully Autel is willing to replace your drone and you only pay for shipping. It may be a bit over $100-200, but it's better than whatever they retail down there.

The air pipes are used to oxigenate the waters. I was explained once, but I forget why.