P4P comes to a stop then restarts during mission

Phantom 4 Pro. When flying a mission, the drone will throw error code dji_check_fc_takeoff_failed_unknown_error. The drone slows to zero velocity (complete stop), then goes back up to mission speed to continue with the mission. It behaves as if it detected an obstacle and slammed on the brakes. At first I thought it was sun flare on the vision system so I cleaned all the sensor faces. No change. I then disabled obstacle avoidance with DJI 4 app. No change. I am mapping large acreage forests and like to fly mid-day with a clear sky, lots of sunlight so I can go fast. I cannot replicate the error free flying using the DJI app.

Jim Watson September 04, 2022 18:14

Official comment

All of your corrective actions were correct. Sadly we have no idea what actually causes that error. Everything that is reported in the Aircraft Errors window is reported directly from the aircraft. Some are more serious that others. It is certainly an automated waypoint flight issue since the takeoff state is part of that. We have had a couple of other users report this as well. It seems like a new problem, which is weird since it isn't correlated with any changes we have made. We would love to hear if you find any patterns for it.

Please email the links to the flight logs these issues occurred in so we can take a closer look.

Tudor September 04, 2022 18:26

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10 comments

Where would you like me to post flight logs?

The error is variable. Some missions I can get in numerous batteries with no issues, on others it will stop and start repeatedly.

Jim Watson September 04, 2022 18:58 0 votes

I uploaded some flight logs to Airdata. You will have to guide me on getting you access to them.

Jim Watson September 04, 2022 21:09 0 votes

Please go into your Maps Made Easy account and find the flights that had issues. Copy the link and email that to mapping@dronesmadeeasy.com

Tudor September 04, 2022 23:50 0 votes

I have the same error on every flight but it doesn't cause any problems for me.

It appeared in both Phantoms I have, a P4A and a P4P v1.

George September 05, 2022 06:26 0 votes

George: We can see that you are also getting that error in your flight logs. We can also see that you and Jim are both using the Movable Home Point feature.

We are not sure if this error is related to Jim's stopping during flight but if both of you could try doing your next flights without the Movable Home Point feature turned on and get back to us to let us know if that error goes away that would be great. We might be able to make some adjustments that would keep this error from showing.

Zane September 06, 2022 17:26 0 votes

Thanks but I never use movable home point.

I have never enabled this setting.

George September 07, 2022 13:02 0 votes

George: Sorry about that. It looks like you weren't. I had about 20 flight logs open and might have gotten them confused. Maybe that's why yours isn't stopping!

Zane September 07, 2022 16:29 0 votes

Since first posting this thread I have flown seven 80± acre missions of about 6-7 air miles each, all with no issues. Movable home point is off, object avoidance is on, flying at 350' AGL (terrain follow) at 15mph in mountainous terrain. Conditions are bright, diffuse light with high overcast. It appears movable home point turned off may be the key. The drone continues to throw lots of "unknown" error messages but it doesn't stop and start.

Jim Watson September 14, 2022 01:37 0 votes

Jim: Thank you for the follow up. We will give that a close look to see what the issue might be and try to fix it.

Zane September 14, 2022 01:47 0 votes