DJI replaced all 4 motors under warranty. My Air 3S crashed on its first flight after the repair — DJI says I hit an obstacle.
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I want to document this properly and get some independent opinions from people who understand DJI drones, motors, ESCs and flight logs.
I'm the owner of this Air 3S, and I originally documented the entire case on MavicPilots. This is not a second-hand story.
The original problem
Before the incident I'm describing, my Air 3S had already developed a motor-related problem.
The front motors were becoming unusually hot, and I was receiving "Rotor Overloaded" warnings. I also noticed abnormal/jerky gimbal behaviour.
I contacted DJI and the aircraft was handled under warranty through the authorized technical center.
The technical center replaced all four motors/rotors, as well as the gimbal/camera assembly.
They also provided me with photographs of the old removed parts.
I later personally confirmed with the technical center that the aircraft's serial number was identical on both visits.
So to be completely clear: this was my original aircraft throughout. It was not a different or replacement aircraft.
The technical center also confirmed that, for this repair, there was no need to send the aircraft itself to DJI; the four motors/rotors were replaced at the technical center.
The aircraft was not flown after that repair
This is an important part of the timeline.
At the time, drone operations in the UAE were restricted, so I couldn't simply take the repaired aircraft out and test it.
The aircraft therefore remained unused after the repair.
According to the information DJI later provided from its flight data, the aircraft had not taken off or powered its propellers even once after the four motors were replaced.
That means the incident I'm about to describe happened on the first flight after the repair.
The first flight after the repair
Months later, when I was finally able to operate the drone again, I had an indoor filming job at a plastics factory.
This was a controlled indoor environment.
Before flying, I checked the area and made sure there were no obvious obstacles in the flight path.
There were approximately 10 people present and watching, including my client.
I took off and the Air 3S initially behaved completely normally.
It hovered steadily.
I was approximately 20 metres high according to my observation at the time.
The drone remained stable for roughly a minute while I was positioning/framing the shot.
Then, completely unexpectedly, the aircraft suddenly started leaning toward the front-left side.
It did not simply descend normally.
It suddenly lost stability and fell.
I have video of the incident.
The people who witnessed it also saw the aircraft simply lose balance and fall.
There was no intentional collision with an obstacle.
What I found after the crash
Immediately after recovering the drone, there was a very strong burnt electrical/burnt-copper smell coming from the aircraft.
The front-left motor had been displaced/popped out of the arm.
The motors were also extremely hot.
The aircraft was taken back to the same authorized technical center.
The technician noticed the burning smell as well and inspected the aircraft.
The second warranty case was then submitted.
DJI's conclusion
After DJI analyzed the aircraft/logs, their conclusion was essentially that the aircraft had been hovering and had crashed with obstacles within the hovering-accuracy range.
That conclusion is extremely difficult for me to accept.
The aircraft had been hovering steadily.
I have video of the incident.
There were around 10 witnesses.
And the aircraft suddenly became unstable toward one side and fell.
There was no obvious obstacle strike immediately preceding the loss of control.
If the flight data actually proves that an obstacle was struck, I'm completely willing to hear that argument.
But I don't believe simply stating that the aircraft "crashed with obstacles" adequately explains what happened.
The motor/contamination explanation
DJI also attributed the motor problem to contamination/foreign material such as dust or particles.
This is another part I am struggling to understand.
The aircraft had just undergone a warranty repair in which all four motors were replaced.
It then sat unused until this first flight.
During that first flight, in a controlled indoor environment, one motor apparently suffered a catastrophic problem and the aircraft lost balance.
After the crash, there was a very obvious burnt electrical smell.
I'm not claiming that I have personally proven the exact electrical failure mechanism.
What I am questioning is whether the contamination explanation actually fits the circumstances.
If a tiny particle of dust can cause a newly replaced motor to fail catastrophically on its first flight, I'd like to understand the technical mechanism behind that claim.
The subsequent technical findings
During the subsequent discussions with the technical center, I was also informed about errors involving the aircraft's power system and ESC/motor system.
The service center explained that further components, including the ESC/power-related components and damaged motor, would need attention.
I was also told that, because the aircraft is an electronic system, they could not guarantee that another problem could never occur after repair.
That made the situation even more concerning to me because this was already the aircraft's first flight after all four motors had been replaced.
An independent test by another drone owner
Something else happened after I posted the case on MavicPilots.
Another member took DJI's contamination explanation seriously enough to perform his own informal experiment.
He deliberately exposed DJI drones/motors to sand/dust and operated them.
He did not reproduce anything remotely similar to a motor burning or failing.
Obviously, this is not a scientific test and does not prove that contamination can never damage a motor.
But it does raise a reasonable question about whether contamination alone adequately explains what happened to my Air 3S.
What I am trying to establish
I'm not posting this simply to say "DJI is bad" or to ask everyone to automatically take my side.
I'd actually prefer technically knowledgeable people to challenge my interpretation if I'm wrong.
If someone can look at the flight data and explain why this looks like an obstacle collision, please tell me.
If there is a known Air 3S behaviour where a motor/ESC can suddenly shut down or lose power in this way, I'd like to know.
If dust or contamination can realistically cause this exact type of failure, I'd also like someone knowledgeable to explain the mechanism.
But if the evidence is more consistent with a motor/ESC/power-system failure, I believe that possibility deserves to be taken seriously.
I have evidence
I have documentation and/or evidence covering:
- The original motor problems and "Rotor Overloaded" warnings
- The first warranty repair
- Confirmation that all four motors/rotors were replaced
- Photographs of the old removed parts
- Confirmation that the aircraft's serial number was the same on both visits
- The fact that the aircraft was not flown after the first repair
- The crash video
- Photos/video of the damaged aircraft
- The burnt electrical smell and physical motor damage
- The second warranty case
- DJI's technical analysis/conclusion
- DJI/service-center correspondence
- The subsequent ESC/power-system findings
- Relevant flight-log information
- The independent sand/contamination experiment
I originally documented the case in detail here:
MavicPilots:
I'm posting this here because I'd genuinely like an independent technical discussion.
What do you think happened?