I lost my Spark, it's now at the bottom of a river, which means my Care Refresh policy doesn't cover me either.

I wanted to briefly pop up the drone to take footage in a gorge before other people came along. I launched from a boat but had no GPS signal at this point. Before you point out that this is all pretty risky: yes I know it is, but I had done just that twice before. Hand launch, hand land, limited GPS, no issues. That is also not what caused the crash.

As I was trying to adjust the aircraft position it suddenly took off, clearly in SPORTS mode, even though I had not activated that on the remote. Unfortunately I ran out of space before I could corect and the craft crashed into a tree and then into the water. The aircraft was going between 17 and 23 mph for about 3 seconds before than happened.

I have raised a case with DJI hoping to get an explanation why the drone would kick into SPORTS mode by itself. Unfortunately their 'analysis' was that due to the aircraft being in ATTI mode it 'drifted' which resulted in the crash. Going at 22 mph isn't a drift in my books; 11+ m/s for 3 seconds means I had more than 30 meters to play with which would have been enough had the aircraft stayed in normal mode.

I was running the latest firmware on aircraft & controller as well as the latest version of GO 4 on an Android phone. And this was not the first time the aircraft kicked inthe SPORTS by itself. The first time I managed to avoid a crash.

Has anyone else seen this behaviour before?

hg

Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

msinger Posted at 2018-9-13 03:01
Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

Thanks mate, did that, there is not really much to see expect the drone taking off at one point. i was hoping there would be a message that SPORTS had been engaged but there isn't - not sure if that means anything

hg87 Posted at 2018-9-13 03:03
Thanks mate, did that, there is not really much to see expect the drone taking off at one point. i was hoping there would be a message that SPORTS had been engaged but there isn't - not sure if that means anything

Well, it means it didn't really switch to sport mode. Feel free to post the log if you'd like a second opinion.

Have a look at this, this is the flight where I almost crashed but managed to find a gap in the trees.
At 2 min 37.5 the aircraft suddenly accelerates to 23 mph. The stick was in the same position before and after.

https://www.phantomhelp.com/logviewer/S2JJPWS4NED9NLCV9B0N/

DJI drones are able to fly faster when in ATTI mode. The Spark switched to ATTI mode during that time, so I can only assume that's what allowed that speed increase. DJI support should be able to confirm that if you  sync your logs and contact them.

msinger Posted at 2018-9-13 03:22
DJI drones are able to fly faster when in ATTI mode. The Spark switched to ATTI mode during that time, so I can only assume that's what allowed that speed increase. DJI support should be able to confirm that if you  sync your logs and contact them.

I have done that and the answer was that the aircraft drifted which caused the crash. I doubt they really looked at the logs.
Under what circumstances would the aircraft fly faster in ATTI mode? It doesn't seem to do so consistently .

hg87 Posted at 2018-9-13 03:25
I have done that and the answer was that the aircraft drifted which caused the crash. I doubt they really looked at the logs.
Under what circumstances would the aircraft fly faster in ATTI mode? It doesn't seem to do so consistently .

Phantoms have a switch on the remote controller that allows the pilot to manually switch to ATTI mode. When flying in ATTI mode, the max tilt angle increases (which allows it to fly faster). Here are the specs for the P4P V2:



The Spark has no such documentation since there is no manual ATTI mode. However, if the max tilt angle also increases when flying in ATTI mode, that would allow the max speed to increase when flying at full stick (like you were doing).

Hi, thanks for reaching DJI Forum. We do feel sorry that you lost your aircraft. However for us to help you with this. Kindly provide us the case number ( CAS )  for us to double check and follow up. We're here to help you. Thank you.

msinger Posted at 2018-9-13 03:34
Phantoms have a switch on the remote controller that allows the pilot to manually switch to ATTI mode. When flying in ATTI mode, the max tilt angle increases (which allows it to fly faster). Here are the specs for the P4P V2:

[view_image]

That is a very plausible explanation, thanks for that. That would mean the controls get a lot more sensitive when the aircraft looses GPS, which happened to me as I descended into the gorge.
It would be useful to know that is how the aircraft behaves.

DJI Gamora Posted at 2018-9-13 03:40
Hi, thanks for reaching DJI Forum. We do feel sorry that you lost your aircraft. However for us to help you with this. Kindly provide us the case number ( CAS )  for us to double check and follow up. We're here to help you. Thank you.

Thanks for reaching out. The case number is CAS-2236387-B7F8K2.

Cheers

hg

hg87 Posted at 2018-9-13 03:42
Thanks for reaching out. The case number is CAS-2236387-B7F8K2.

Cheers

Hi, thank you for your fast response. I will coordinate this to the department who will be handling your case. Cheers.

DJI Gamora Posted at 2018-9-13 03:47
Hi, thank you for your fast response. I will coordinate this to the department who will be handling your case. Cheers.

Thanks again for your kind help.

hg

hg87 Posted at 2018-9-13 03:48
Thanks again for your kind help.

hg

Hi Hans, we're sorry for your loss. I checked the flight records you submitted to our Data Analysis and it shows that the unit was in ATTI mode when it crashed. You can check the screenshot below for your reference. Please note that it is not advisable to fly your drone in an area with no or weak GPS signal. Without the signal, your drone will not determine the home point recorded which can result to fly away case. Further information about ATTI mode is in our manual and I attached the screenshot below. However, I forwarded your concern to our Managerial Team for further handling. Please keep your line accessible as we'll contact you within 48 business hours for the feedback. Hope for your patience.

Diana,
again many thanks for your reply. I am well aware of the risks of flying without GPS lock, however, this was not the cause of the issue in this case. I was in control of the aircraft which held its position reasonably well until, responding to my stick input, it accelerated beyond the speed I was expecting. Find two examples of this behaviour in the logs below.

So far the explanation provided by msinger appears to be the most reasonable: that in ATTI mode the aircraft can fly at SPORTS speeds even when SPORTS mode is not engaged. I did not foresee this behaviour - which I believe is undocumented - and as a result I provided too much stick input. You can see how the aircraft accelerates to more than 20 mph.
Could you please confirm if this is expected behaviour?

Many thanks

hg

hg87 Posted at 2018-9-13 13:23
Diana,
again many thanks for your reply. I am well aware of the risks of flying without GPS lock, however, this was not the cause of the issue in this case. I was in control of the aircraft which held its position reasonably well until, responding to my stick input, it accelerated beyond the speed I was expecting. Find two examples of this behaviour in the logs below.

Hi hg, your case has been escalated to the appropriate team to double analyze, we will have someone to follow up your case and keep you updated, please wait patiently, thank you.

DJI Mindy Posted at 2018-9-14 02:01
Hi hg, your case has been escalated to the appropriate team to double analyze, we will have someone to follow up your case and keep you updated, please wait patiently, thank you.

Hi Mindy, thank you very much for your kind support ,I really appreciate your help. hg

hg87 Posted at 2018-9-14 04:02
Hi Mindy, thank you very much for your kind support ,I really appreciate your help. hg

You are welcome Hans. If you have any other concerns please feel free to contact DJI support for further help.

Thanks Diana. We are on a year-long trip around Australia and have been able to get some amazing footage in a lot of really remote places. So far we have had a good run with the spark and would very much like to continue in the coming months. Looking forward to your findings and response.

hg

hg87 Posted at 2018-9-14 19:56
Thanks Diana. We are on a year-long trip around Australia and have been able to get some amazing footage in a lot of really remote places. So far we have had a good run with the spark and would very much like to continue in the coming months. Looking forward to your findings and response.

hg

Hello hg, the management is reviewing your case and will keep follow up. There might be some delay due to the weekend, please kindly wait. We'll keep an eye on the status as well. Hope we can figure this out soon.

I know this is an older post but wanted to reply as I've also had this same issue the past 3 months or so.  I've noticed this occurring 3 times now and these have been during the last 3 trips that I took my drone out.  It does not happen everytime I fly but it does happen probably 1 out of 10 times I fly now.  Inlcuded is a a URL that shows this happening and causing a pretty bad crash.  I'm suprised that the drone actaully still works after this crash.     

sirrahc_nash Posted at 6-17 08:37
I know this is an older post but wanted to reply as I've also had this same issue the past 3 months or so.  I've noticed this occurring 3 times now and these have been during the last 3 trips that I took my drone out.  It does not happen everytime I fly but it does happen probably 1 out of 10 times I fly now.  Inlcuded is a a URL that shows this happening and causing a pretty bad crash.  I'm suprised that the drone actaully still works after this crash.     https://www.youtube.com/watch?v=jS_b74dqCf4

Hi there, I'm sorry to read the crash. According to your video, it looks like the drone entered ATTI mode as the GPS signal is not strong. Also, it is not recommended to fly the drone after the crash, you may start a case and send it in for diagnosis: https://www.dji.com/support