Mavic suddenly jerked to the right while flying in woods

[RonanCork]

Hi Guys,

Was wondering if I could get some help from you. I was flying (Mavic Air) in a local woods (heavy tree canopy so I was about 2m off the ground and generally not flying over the tree canopy in that area). I was (from what I recall in Sports mode, so it's APAS would let me move more easily close to objects) in sports mode and flew slowly down a path with trees about 1/2m to the right. At one point (it was about 5/10m from me) I noticed the drone bank/jerk to the right sharply and suddenly when I was just pushing the pitch down to fly ahead. This happened about 15 mins later also

My list of flight logs that morning (as between 7:05am and 8:15am I flew around different parts of the woods, i.e landing, switch off drone, walk to another part of woods, launch drone there etc) is listed in the attached screenshot flight_log_list.png. The time if happened from what I recall was around 8am on Sun 22 April (yesterday). So I'm guessing this will be one of the items in the red box in flight_log_list.png ?

Let me know if I need to be more exact with my information etc if I've included too much to make things easier for you guys

Below is my report:

Was unit in a crash? 4 days previously (on 19 April) I did collide with a power line/cable. Part of one of the propellers broke off and I was able to get the bird home (200m away), it indicated "Motor Error" in the app at that time. I did land in wet grass for about 5s before I picked it up. I replaced the propeller and was able to fly fine the next day
What have you tried so far? Nothing yet
What device are you using ( iphone , ipad, Samsung , etc)? Huawei P20
What firmware are you running ( aircraft, remote controller)? In office now so I can check when I'm home
What Go app version are you using? 4.3.14
Any modification? (if so what) No.
Did you change anything or install any apps? (if so what) No
Do you have a video or pictures of the problem? (if so post link) No I don't sorry

Any help / guidance would be great.

Thanks Ro

 

[brett8883]

Hi Guys,

Was wondering if I could get some help from you. I was flying (Mavic Air) in a local woods (heavy tree canopy so I was about 2m off the ground and generally not flying over the tree canopy in that area). I was (from what I recall in Sports mode, so it's APAS would let me move more easily close to objects) in sports mode and flew slowly down a path with trees about 1/2m to the right. At one point (it was about 5/10m from me) I noticed the drone bank/jerk to the right sharply and suddenly when I was just pushing the pitch down to fly ahead. This happened about 15 mins later also

My list of flight logs that morning (as between 7:05am and 8:15am I flew around different parts of the woods, i.e landing, switch off drone, walk to another part of woods, launch drone there etc) is listed in the attached screenshot flight_log_list.png. The time if happened from what I recall was around 8am on Sun 22 April (yesterday). So I'm guessing this will be one of the items in the red box in flight_log_list.png ?

Let me know if I need to be more exact with my information etc if I've included too much to make things easier for you guys

Below is my report:

Was unit in a crash? 4 days previously (on 19 April) I did collide with a power line/cable. Part of one of the propellers broke off and I was able to get the bird home (200m away), it indicated "Motor Error" in the app at that time. I did land in wet grass for about 5s before I picked it up. I replaced the propeller and was able to fly fine the next day
What have you tried so far? Nothing yet
What device are you using ( iphone , ipad, Samsung , etc)? Huawei P20
What firmware are you running ( aircraft, remote controller)? In office now so I can check when I'm home
What Go app version are you using? 4.3.14
Any modification? (if so what) No.
Did you change anything or install any apps? (if so what) No
Do you have a video or pictures of the problem? (if so post link) No I don't sorry

Any help / guidance would be great.

Thanks Ro

I’ll take a look but if you knew on which of the flights this occurred

Hi Guys,

Was wondering if I could get some help from you. I was flying (Mavic Air) in a local woods (heavy tree canopy so I was about 2m off the ground and generally not flying over the tree canopy in that area). I was (from what I recall in Sports mode, so it's APAS would let me move more easily close to objects) in sports mode and flew slowly down a path with trees about 1/2m to the right. At one point (it was about 5/10m from me) I noticed the drone bank/jerk to the right sharply and suddenly when I was just pushing the pitch down to fly ahead. This happened about 15 mins later also

My list of flight logs that morning (as between 7:05am and 8:15am I flew around different parts of the woods, i.e landing, switch off drone, walk to another part of woods, launch drone there etc) is listed in the attached screenshot flight_log_list.png. The time if happened from what I recall was around 8am on Sun 22 April (yesterday). So I'm guessing this will be one of the items in the red box in flight_log_list.png ?

Let me know if I need to be more exact with my information etc if I've included too much to make things easier for you guys

Below is my report:

Was unit in a crash? 4 days previously (on 19 April) I did collide with a power line/cable. Part of one of the propellers broke off and I was able to get the bird home (200m away), it indicated "Motor Error" in the app at that time. I did land in wet grass for about 5s before I picked it up. I replaced the propeller and was able to fly fine the next day
What have you tried so far? Nothing yet
What device are you using ( iphone , ipad, Samsung , etc)? Huawei P20
What firmware are you running ( aircraft, remote controller)? In office now so I can check when I'm home
What Go app version are you using? 4.3.14
Any modification? (if so what) No.
Did you change anything or install any apps? (if so what) No
Do you have a video or pictures of the problem? (if so post link) No I don't sorry

Any help / guidance would be great.

Thanks Ro

If you are able to figure out exactly which one of these logs are for the flight in question that would be most helpful. It rolled to your right or the drones right? How far into the flight did this happen? How long did the roll excursion last? It can sometimes be difficult to pin point minor events in the logs if we don’t know where they are. It’s much easier to recognize say a crash since it’s pretty easy to tell when the motors stop.

Any information you could give describing the event in more detail would be helpful.

 

[RonanCork]

Hi,

No problem. Leave it with me and I'll get the exact flight log tonight and answers to your questions.

Thanks Ro.

 

[RonanCork]

Hi again,

Quick one - just to help me narrow down the correct flight log,

In the case of a flight log named "DJIFlightRecord_2019-04-22_[08-00-24].txt" - well is the time stamp of "08-00-24" representative of when the flight log was first created or does it represent the time the log was last written to ?

Thanks Ro.

 

[sar104]

Hi again,

Quick one - just to help me narrow down the correct flight log,

In the case of a flight log named "DJIFlightRecord_2019-04-22_[08-00-24].txt" - well is the time stamp of "08-00-24" representative of when the flight log was first created or does it represent the time the log was last written to ?

Thanks Ro.

That's the start time of the flight in local time.

 

[RonanCork]

Hey,

Thanks for that - ok so I was able to narrow it down.

I'm confident the flight log is this attached one (DJIFlightRecord_2019-04-22_[08-15-15].txt).

To answer your additional questions:
1. The drone rolled to my right. It was moving away from me (in sports mode i think) with the head of the drone pointed away from me. It was 10ft approx or more off the ground with trees to it's right hand side, at least a couple of feet away from the trees.
2. The jump to the right happened I would say between 10s - 60s into the flight
3. The jump lasted for about 1 or 2 seconds approx.

Hope this helps.

Thanks Ro

 

[RonanCork]

Hey guys.

This is the flight log from the GO app. It looks a little odd and choppy. Guessing it's the trees causing a reduction in GPS accuracy. Hope this helps.

Thanks Ro

 

[Meta4]

At one point (it was about 5/10m from me) I noticed the drone bank/jerk to the right sharply and suddenly when I was just pushing the pitch down to fly ahead. This happened about 15 mins later also

Your flight data looks like this: DJI Flight Log Viewer - PhantomHelp.com
Your flight was under very patchy GPS conditions because of the thick tree cover.
You only had full (5) GPS health for 10 seconds in the whole flight.
GPS health was very poor (0 or 1) from:
0:07.1 - 0:17
0:29.7 - 0:34.8
1:30.9 - 1:36
During those times the drone would be ignoring whatever GPS information it could get as it would be unreliable and it would estimate its position based on the last reliable position, possibly also allowing for with speed and direction.
Position in those times would only be approximate but when a gap in the trees allowed a better quality fix.
Flying in those conditions with GPS drifting in and out, you might see jerky movement of the drone .
It would have been smoother if you had no GPS or full GPS but having GPS coming and going was probably the issue.

 

[RonanCork]

Hi Guys,

Thanks for the detailed response. I was thinking the tree cover was a part of the issue, as when I was flying in a more open area of the woods and by the edge of the woods (on the outside of the woods high over the canopy) all seemed fine.

Thanks again! - Ro