Cetacean
 Captain
Flight distance : 2528264 ft
United States
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Aloha Salim,
Please be sure to put your Mavic Air in a cloth bag, like a pillow case, before you put it in rice. The pillow case keeps the rice and rice powder from getting in the motors and body and causing problems. If you did not put the Mavic Air in a cloth bag, be sure to check the Mavic Air for rice dust and rice and use compressed air, if you can, to blow out any rice or dust.
Then take off the propellers and see if the motors turn. If they turn easily and just like each other, try to start the motors with a different battery. I have never done this with a Mavic Air, so I do not know if it is possible. Otherwise, replace the propellers, go to a safe area when it is not freezing, or real cold, and try to start it up. See if it will hover.
The flight record indicates in the first line that the battery was not warm enough to be flown safely. DJI does sell battery warmers. The temperature you note was at freezing, 0 degrees Celsius. The conditions were high humidity, foggy. The motor obstruction could have been freezing water drops but I do not know for sure.
The voltages and deviations should be read by another Forum Member to evaluate anything I say next. The voltages and deviations indicate that Cell 3 was consistently lower than Cells 1 & 2. This created unsafe deviations as seen in the colored numbers. I would recommend that you not fly this battery except under very controlled conditions, when it is warm, so you can see how compromised the battery is.
Hopefully, the battery will work properly in warm weather. But, it really seems that the freezing and humid (foggy) conditions caused your problem. Do you regularly fly in freezing conditions?
If you have to fly when it is freezing, make sure it is not also humid (foggy). Be sure to warm the battery before you go outside and fly. Do not let the battery cool off. Some people put it inside their coat. The motor goes through temperature changes depending on RPM. In your case, the motors were not working hard and getting hotter since your Mavic Air was hovering most of the time. The battery cells go through temperature changes as each cell releases voltages and Cell 3 was apparently coldest since it was not working well with the other cells causing the deviations.
The recommendation at the beginning to warm up the battery would have given the battery a better chance to work properly during the entire planned flight. The motors were not working hard and getting hotter since your Mavic Air was hovering most of the time.
The reduced voltages appear to have not been able to keep the motors working well enough to keep turning as the fog water drops turned into ice. With the weak voltages and no high RPM to heat the motors better, enough ice formed to obstruct the motors or a particular motor. The shaking was when the motor slowed or stopped and the flight controller tried to compensate. Eventually, the flight controller shut down the Mavic Air motors.
Hope this helps!
Aloha and Drone On! |
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lvl.1
First Officer
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