Pursuing a refund - Flyaway not found...

[flyNfrank]

Interesting, Frank. Are you pointing to the very last datapoint or two where it looks like the red and blue lines are beginning to drop? What tool is this?

I'm referring to the far right of the image where the lines just begin to come out from behind the indicator display. You can see it better if you click on the image to view a larger version. The graph is part of the user account on flightreplay.com.

I like doing high speed flights and use this graph to show me where the aircraft reaches it's top speed, top speed with tailwind, adjusting pitch, the angle spikes on vertical speed, and more

 

[flyNfrank]

@flyNfrank...I don't see a great change in those values. I am thinking your chart might be exaggerating the slope due to the fact that the last few pieces of data are 1.2 seconds apart (where most previous data points are .1 seconds apart). Is your X axis a function of time? If not, the last few data points might be inappropriately compressed...exaggerating the down slope. Speed and altitude don't seem to be varying much, when you take time into account.

Here's a chart of speed...charted as a function of time.
View attachment 26872

I use what I know to be available. If you have the time and ability to build and create a program that uses the info from a comprehensive log file created on djilogs.com I would support it even on my own website. I predict some 100 pilots, maybe more, worldwide that my be interested in using it.

 

[RoyVa]

Don't forget about electronics or sensor failures. All it take is a transistor or resistor to fail. Even you guys Sid third was a battery glitch for s split second. That's all it take to cause a system reboot and if that happens and the memory was cleared ... She would not know where she was or where to go. She just flies till critical battery level then auto lands. Just like something you are working on with your computer and it reboots on you. That info is lost and it starts over. If it was me I would take a walk streight out in the direction your log showed and at least look around. You can figure pretty close the remaining battery power and how far she could go. Sorry for your loss and good luck in the future.

 

[III% Streve]

I think Steve (but he'll have to clarify) was assuming the bird went down shortly after telemetry ended...where my model shows where the ground (or obstructions) would have risen into the path of the bird, had it continued to hold its altitude.

My location assumed a cruise altitude of 428 (i think Im remembering) feet and didn't take into account any ground level changes. It was also just a quick crunching of estimated numbers. That why I also included the general breakdown of how I would have done the math. I can definitely see the other estimations having equal merit.

 

[Leon001]

My location assumed a cruise altitude of 428 (i think Im remembering) feet and didn't take into account any ground level changes. It was also just a quick crunching of estimated numbers. That why I also included the general breakdown of how I would have done the math. I can definitely see the other estimations having equal merit.

No problem. The Reason I ask is, with predictions ranging from (a) the point where the log ends, to (b) Taz's prediction and to (c) your prediction plus the difference in distance between the two... We are left with quite a large fan opening up to the north east. That's a large, large area.

Now, that isn't a criticism and I'd hate for any of you to think I was being unappreciative. All I'm saying is that without being able to attach more or less confidence to the various predictions you've all made, the search area is too large.

I'll tell you what though, I'll be sad if I don't find the drone and continue my short time as a pilot, not only because of the money, or even the great flying and views. But because of how interesting your inputs have been on the thread.

The technical and analysis part of dealing with a drone are at least as interesting as the actual flying.

 

[Leon001]

I estimate this would make for a search a search area of, perhaps, 9 square kilometres.

 

[Leon001]

Here's what a member with the handle "Willie Wonka" over at the DJI forum had to say, and it's particularly interesting because of what he says about the battery...

The logic is that 3 possibilities , first one is one motor dies and it goes in a spiral, second and third is one cell damaged in the battery and that causes sudden drop in voltages and go back up which in some cases the controller looses its data and just go full throttle with not purpose until battery dies completely which happens fast and then it drops down like a rock.
​

I have read posts on this thread that comment both that the drone was going very fast AND that there was some strange battery activity shown on the log.

The above explanation was supposed to elucidate this picture...

 

[TAZ]

I estimate this would make for a search a search area of, perhaps, 9 square kilometres.

I agree the search area for all possibilities is too large. Certainly if you were to assume the bird could've fallen out of the sky at some point on its path. However, there's nothing to indicate it did (likewise, there is nothing that says it didn't either...). It is rare for charged Phantoms to fall out of the sky (even more rare than for them to fly off uncontrollably). It certainly had enough battery to fly for a very long ways. Your battery log data doesn't indicate an error...so I think it reasonable to assume it would've kept heading along its path. That is an assumption though.

However given the track data we do have...it's easy to estimate its path. IF it stayed in the air. Given the rise of elevation of the surrounding land it most likely didn't fly until it ran out of battery. It likely ran into the rising topography. That is one fortunate thing about your situation...the search area does look to be limited by the rising topography.

If I wanted to make a targeted and small effort, I'd put signs up on the short few blocks identified in the red area. I also would check the tree line of the park directly opposite as those trees appear to be a substantial barrier at the same location where the obstruction altitude would've met the birds height. The neighborhood identified in the red area is pretty small. It appears the area prior to it is easily accessible being a park. Maybe worth a shot.

I wouldn't say a good estimate of your search area is necessarily 9sq km. I'd think it much smaller...limited to the area of the line where the topography meets the birds elevation.... I don't think I was clear in communicating my previous overlay. I'm not suggesting you search the entire yellow area...just where the yellow polygon meets the earth.

I've included a new overlay (blue). The edges of it is the limit of where the bird could travel without climbing allowing for a wider range of heading than the flight data we do have predicts. It is the terminating edge of this blue polygon where the bird couldn't have flown far beyond without crashing into an obstruction or the ground. A vast majority of it terminates in open fields. Pretty unlikely someone saw it go down, or found it there...also unlikely you can traipse around with a chance of stepping on it. Again here, I'm not suggesting the bird is anywhere in the blue area...just the ground elevation along its terminating edge would've prevented it from going beyond that.

You can just reload the updated .kmz file to inspect the blue polygon.
https://onedrive.live.com/redir?resid=9D9108EB917328CA!1575&authkey=!AD0F4815oUMGUKU&ithint=file,kmz

 

[Leon001]

I agree the search area for all possibilities is too large. Certainly if you were to assume the bird could've fallen out of the sky at some point on its path. However, there's nothing to indicate it did (likewise, there is nothing that says it didn't either...). It is rare for charged Phantoms to fall out of the sky (even more rare than for them to fly off uncontrollably). It certainly had enough battery to fly for a very long ways. Your battery log data doesn't indicate an error...so I think it reasonable to assume it would've kept heading along its path. That is an assumption though.

However given the track data we do have...it's easy to estimate its path. IF it stayed in the air. Given the rise of elevation of the surrounding land it most likely didn't fly until it ran out of battery. It likely ran into the rising topography. That is one fortunate thing about your situation...the search area does look to be limited by the rising topography.

If I wanted to make a targeted and small effort, I'd put signs up on the short few blocks identified in the red area. I also would check the tree line of the park directly opposite as those trees appear to be a substantial barrier at the same location where the obstruction altitude would've met the birds height. The neighborhood identified in the red area is pretty small. It appears the area prior to it is easily accessible being a park. Maybe worth a shot.

I wouldn't say a good estimate of your search area is necessarily 9sq km. I'd think it much smaller...limited to the area of the line where the topography meets the birds elevation.... I don't think I was clear in communicating my previous overlay. I'm not suggesting you search the entire yellow area...just where the yellow polygon meets the earth.

I've included a new overlay (blue). The edges of it is the limit of where the bird could travel without climbing allowing for a wider range of heading than the flight data we do have predicts. It is the terminating edge of this blue polygon where the bird couldn't have flown far beyond without crashing into an obstruction or the ground. A vast majority of it terminates in open fields. Pretty unlikely someone saw it go down, or found it there...also unlikely you can traipse around with a chance of stepping on it. Again here, I'm not suggesting the bird is anywhere in the blue area...just the ground elevation along its terminating edge would've prevented it from going beyond that.

You can just reload the updated .kmz file to inspect the blue polygon.
https://onedrive.live.com/redir?resid=9D9108EB917328CA!1575&authkey=!AD0F4815oUMGUKU&ithint=file,kmz

View attachment 26894

Wonderful. I'll be heading out to search in 8 and a half hours. I should have the results of my search in 10-11 hours.

You've certainly convinced me that this area is worth a shot. I know it's not foolproof, but like I say, a shot.

 

[Sprague]

Leon001... Perhaps OHB?

 

[Leon001]

Leon001... Perhaps OHB?

I'm not familiar with OHB... do tell?

 

[TAZ]

Wonderful. I'll be heading out to search in 8 and a half hours. I should have the results of my search in 10-11 hours.

You've certainly convinced me that this area is worth a shot. I know it's not foolproof, but like I say, a shot.

Good luck! As others have pointed out...my assumptions fall apart if the bird continued to hook to the right. I've no data to say if it did or didn't. All I can tell is the flight path curve seems to decrease over time. But there just isn't enough data to assume either way. The above model is just one possibility supported by the data we do have. Other than walking the entire blue area terminus...as you say, this one is worth a shot. It's pretty hard to justify assumptions based on how things will work....when we already know the bird wasn't behaving predictably in the first place. Hope it's not a wild goose chase!

 

[Leon001]

Good luck! As others have pointed out...my assumptions fall apart if the bird continued to hook to the right. I've no data to say if it did or didn't. All I can tell is the flight path curve seems to decrease over time. But there just isn't enough data to assume either way. The above model is just one possibility supported by the data we do have. Other than walking the entire blue area terminus...as you say, this one is worth a shot. It's pretty hard to justify assumptions based on how things will work....when we already know the bird wasn't behaving predictably in the first place. Hope it's not a wild goose chase!

Well, search concluded and no sign of the drone. I've posted and put up flyers all around the area, and now everything is in the hands of the people of Broad Oak Lane.

I'd add that I could have been metres from the bird without even knowing. It could have been in the trees, in the bushes, or in the grass. I'd suggest to any pilot of one of these things to get some kind of gps tracker. Without it, even if you do know the rough location of a fly away or crash (and in our case we didn't "know", but only tried to predict) then its still going to be very, very difficult to find it in this kind of area.

Many thanks to Streve and aTaz for their help.

 

[Leon001]

Ok, so here's an update...

No sign of my fly away P3, but my dealer has been back in contact, only three working days after notifying them of the issue.

They passed the flight logs to DJI and the verdict is that the fly away was NOT DUE TO PILOT ERROR!

I'm obviously very happy with the result.

I've since asked for more detailed information on the cause of the fly away and hope that it will be forthcoming.

They have offered a full refund or a replacement within 24 hours. I'm yet to decide what I want to do.

I didn't contact DJI directly and all of this has been handled by the dealer (first person view) over here in the UK.

I just though you'd all like to know.

 

[III% Streve]

Great to hear Leon! Glad that going the route you did, through the dealer, worked out as well. DJI SHOULD be allowing their dealers to take care of their customers. Its just good business.

 

[bbfpv]

awesome. congrats.

 

[ianwood]

Here's what a member with the handle "Willie Wonka" over at the DJI forum had to say, and it's particularly interesting because of what he says about the battery...

The logic is that 3 possibilities , first one is one motor dies and it goes in a spiral, second and third is one cell damaged in the battery and that causes sudden drop in voltages and go back up which in some cases the controller looses its data and just go full throttle with not purpose until battery dies completely which happens fast and then it drops down like a rock.​

If one motor died, it would fall out of the sky very quickly. In fact, if anything happened to any prop, motor or ESC, the most likely outcome would be immediate instability and crashing.

Cell voltage drop is plausible but it doesn't explain what happened as result of the cell drop.

Glad to hear you're getting covered for it.

 

[SteelGator]

Good result for you. I vote that you get a new one. To paraphrase Garp,

"the chances of another fly-away are astronomical. You've been pre-disastered."

Of course if you remember the outcome, YOUCH!

 

[III% Streve]

Lol... Pre-disastered. Gotta use that one in the future!

 

[Toadmanor]

Motorcyclist always state: there are those who have and those who will crash!