I was flying from ground straight up when I got a Yaw Error and the drone flied away really fast. I pressed the RTH button on the remote, but nothing happened. The drone quickly got out of sight, due to a big building who blocked my visual. During the time it took me to get around to the other side of the building, the drone hade drifted further off. Other errors kept popping up until it finally went into RTH mode, 2,3 km away. I was lucky to get my drone back, but what was the cause of this?
I don’t now if I dare to fly it anymore. I normally fly close to no fly zones, and if the drone drifts away 2,3 km in the wrong direction it can lead to a disaster.
Can anyone help me to understand what happened and how I can avoid this happen again in the future?
(If you are a member of OFFICIAL DJI OWNERS GROUP on Facebook, there are a description of this adventure in this thread, including a movie of the dramatic landing with battery on 0%: Redirecting... )
This is due to the YAW and Compass error right after takeoff. This usually occurs when taking off near a metallic surface or object. I suspect that the parking area of your takeoff point contained re-bar embedded in the concrete which cause the compass error.
The aircraft switched to ATTI mode, which means no GPS positioning and began drifting with the wind. ( You still had full manual control, but likely were unfamiliar with flying in ATTI ) After the aircraft had drifted at ~24kph in the wind for over 5 min, it was far away as you stated. The aircraft performed as it was designed to do by switching to ATTI when this error occurs.
As for the remainder of the flight. The compass error went away when you successfully initiated RTH, however by that time there was insufficient battery to make it all the way back to the home point.
Thank you! It is true I have not much experience in flying in ATTI mode. At least not with no visual of the drone (flying by camera or map only).
I took off in a parking lot and the roof of the building contains metal as well. The error probably occurred when I got closer to the roof. But I felt like I had very little manual control over the drone while in ATTI mode. Apart from taking it up to maximal altitude, I couldn’t make it turn and come back to me. I felt like I couldn’t do anything until it finally got into RTH mode.
On the other hand, I was afraid to crash into the building and wasn’t acting fast enough when it started drifting away. The first minutes I was focused on take the drone high up in the air and get myself around the building to get a visual.
Anyway, why did it go away so fast when in ATTI mode? I understand it can’t hover with any precision, but wouldn’t it at least “try” to hover? Was it only the wind to blame? In my eyes, the drone “flew” away, not only drifted away by the wind.
How do I avoid this in the future? Stay away from metal and high winds? Anything else?
If the drone goes into ATTI mode, which it do a lot, what is the best to act (if it is not possible to land asap?)
It was hovering, but it’s not able to hold its horizontal position when in ATTI mode. The speed was due to a mix between the wind and your stick inputs.
Make sure the Mavic is not near any type of magnetic metal objects while it’s powered on. Do these checks to ensure the compass is not be negatively affected before taking off.
The drone should not go into ATTI mode often. If that’s occurring often, you are likely either doing something wrong or your Mavic might be damaged.
If the mode changes to ATTI mode due to a yaw (compass) error, you should not attempt to steer the drone in any direction (other than up/down). If possible, land it in a safe area as quickly as possible. If there is no safe place to land, the only thing you can really do is increase the altitude to clear any nearby obstacles (including obstacles in the direction it’s heading).
Rough calculations indicate that the aircraft was drifting ( As I mentioned above ~24KPH ) which says the wind was a major factor. It will “hover” but only to maintain altitude per the barometer. There is no GPS positioning to hold the aircraft in a still hover in ATTI mode.
I have not realized that the drone’s compass is so sensitive to nearby metal. Many times I have taken off close to my car. Maybe that’s why I often get the ATTI mode?
Also learn to fly in ATTI mode, get well practiced in it … this skill can get you out of serious trouble when you least expect it. Remember to stay calm and go easy on the command sticks when in this mode.
