Hi.
After my last flight i have been wondering what went wrong right after takeoff.
For as short as a second I lost control with my I2, and it was heading in the direction
of some trees.
As I remember, I did not touch the stick coursing it to head that direction. Can someone help me
analyze what could be the course that this happened?I know it seems to be kind of overreacting for only loosing control for about a second, but it could
have been fatal if I did not get the control back that fast.


I lost control at 00:48:05
Started to regain control at 00:49:04
Got full control at 00:49:06

Link to the logfile:
https://www.phantomhelp.com/LogViewer/0EXMYWJQ8IOOKT65GMEQ/#

Thanks in advance.

Do you fly type 1 or type 2? (left stick throttle or right stick)

also, why did you continue to fly the sUAS after experiencing this anomaly?

HyperSpectral Posted at 3-13 10:51
Do you fly type 1 or type 2? (left stick throttle or right stick)

also, why did you continue to fly the sUAS after experiencing this anomaly?

Type 2.
I continued because I got control back after one sec. I couldn’t tell if I did something wrong with the sticks or not.
There were no warnings at all on the screen and no problem controlling the inspire afterward.

Starting around 47 seconds the aircraft heavily banks to the right, and then banks to the left. It looks like the flight controller attempted to hold an erroneous position and then corrected itself during your left aileron input.

I wouldn't fly it again until you determine the reason.

Can you upload the .dat to airdata? it provides more information

HyperSpectral Posted at 3-14 03:41
Starting around 47 seconds the aircraft heavily banks to the right, and then banks to the left. It looks like the flight controller attempted to hold an erroneous position and then corrected itself during your left aileron input.

I wouldn't fly it again until you determine the reason.

Here is a share link for the flight in Airdata:
https://app.airdata.com/share/UNELHY

FarmerMac Posted at 3-14 04:25
Here is a share link for the flight in Airdata:
https://app.airdata.com/share/UNELHY

Nothing really sticks out other than the fact that the landing gear were lowered at 00:47s right when this occurred. Does this sound right?
edit: it looks like the i2 lowered the gear when they were already down, and then decided to raise them? did you possibly move the landing gear switch multiple times?

HyperSpectral Posted at 3-14 05:49
Nothing really sticks out other than the fact that the landing gear were lowered at 00:47s right when this occurred. Does this sound right?
edit: it looks like the i2 lowered the gear when they were already down, and then decided to raise them? did you possibly move the landing gear switch multiple times?

Well.. Nothing special happened when taking off, except the short loss of control.
I was taking off manualy as I always do. The landing gear is set to raise and lower automaticaly.
There is no landinggear switch on the Cendence controller, except one of the preprogrammed
bottons on the controller. I did not touch that one

After the flight where this happened I had one  more flight on a new set of batteries. There where
no problems at all this time.
I'll find a open wide space to do some testflying as soon as possible to find out if something similar
happens again. If nothing goes wrong it must have been a random insident.

I think this is something the DJI team should look into nonetheless.

I would send in this information to DJI support and ask them to open a case, at least so you cover yourself if an accident occurs

HyperSpectral Posted at 3-18 03:57
I think this is something the DJI team should look into nonetheless.

I would send in this information to DJI support and ask them to open a case, at least so you cover yourself if an accident occurs

Hey.
Thanks for the advice. Ill try reach out for DJI and ask them what they think about this issue

HyperSpectral Posted at 3-18 03:57
I think this is something the DJI team should look into nonetheless.

I would send in this information to DJI support and ask them to open a case, at least so you cover yourself if an accident occurs

Well.
DJI just told me to recalibrate IMU and compass. No need for futhere investigation..

FarmerMac Posted at 3-20 03:37
Well.
DJI just told me to recalibrate IMU and compass. No need for futhere investigation..

Typical response. They're not wrong to recommend that, but it certainly wouldn't make me feel any better.

Before you do the IMU and Compass calibration, can you take it back to the same place and look at the variances in the "advanced sensors" menu

Do this before the next few flights, if it doesnt happen again and the variances are low it could have been the calibration of the accelerometer... but i doubt it. It performs an initial calibration every time it turns on, hence why you're not supposed to touch it for the first 20-30 seconds

Hi FarmerMac,

Had a look at your flight as well.

What is notice is that at startup the distance to Home did change from zero to 7.9 meters.
Distance changing from this 7.9 to 8.9 and back to 8.1 meter, this during  AssistedTakeoff with no input and craft on the ground.

After lift off the HP is set, distance to home is set to zero.
Somehow the drone is confused and tries to correct and start to fly to the old position.

During flight a short error :  GpsPositionNonMatch, this for 0.5 second. If this has a link to the start of the flight, have no idea.
Checked several other flights and i see the same thing happening ; after takeoff HP is set and the distance to home is set to zero.
But the offset values are always much less tahn your 7.9 at startup.
Not sure about this but the values are not much seen in other logs.

cheers
JJB

JJB* Posted at 3-25 02:33
Hi FarmerMac,

Had a look at your flight as well.

Thanks a lot for taking time to analyze my flightdata JJB.
I have been on two flightjobs since the one where I lost control. Prior to thoose
two flight I testet the drone, letting it hover 1-2 mtr above homepoint. It was
steady as a rock for several minutes, (or at least as steady as a Inspire 2 can be)
with no issues.
I dont think there is anything wrong with the drone. It might have been a short
malfunction. When all comes to all its just electronics. A reboot can fix a lot of
things.

FarmerMac Posted at 3-25 06:40
Thanks a lot for taking time to analyze my flightdata JJB.
I have been on two flightjobs since the one where I lost control. Prior to thoose
two flight I testet the drone, letting it hover 1-2 mtr above homepoint. It was

hi,

yes, i agree with you. just keep it in the mind.

many happy landings,
cheers
JJB

Hi Farmer Mac. I crashed my inspire2 yesterday. 10 sec after take-off it was stable, with satelites. I mouved it left before tale more altitude. And than je mouved straight on The building and don’t stop and crashed on The wall of the building ... 1 motor and propeller bronen and little fpv caméra broked... I used my Mavic to finish work yesterday

fans5446d373 Posted at 10-27 01:06
Hi Farmer Mac. I crashed my inspire2 yesterday. 10 sec after take-off it was stable, with satelites. I mouved it left before tale more altitude. And than je mouved straight on The building and don’t stop and crashed on The wall of the building ... 1 motor and propeller bronen and little fpv caméra broked... I used my Mavic to finish work yesterday

Hi,

If you like post your flightlog on here, using > https://www.phantomhelp.com/LogViewer/Upload/

Log will tell what mayby happend to your drone, why it went unstable.

cheers
JJB