Today my 7-inch FPV drone crashed during flight.
The direct cause was my control mistake — I was flying in Stabilize mode, lowered the throttle too much, and the drone quickly hit the ground.
However, the real issue happened after the initial impact.
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The landing gear struck the ground hard, and the rear-right propeller (Motor 2 in Quad X) hit the surface for a moment.
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Immediately after the impact, I increased the throttle again, and the drone lifted to about 50 cm. Up to this point, it was maintaining level flight.
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Suddenly, the thrust on the left motors increased, the drone flipped to the right, and then crashed. During this moment, I did not give any roll input.
Since the drone was in Stabilize mode, which is supposed to maintain level attitude, this unexpected flip seems very weird.
It’s possible that the impact caused a temporary malfunction in ESC.
I recorded a short video, although the drone is hard to see because it was filmed from a distance. I will attach it as well.
To investigate the cause, I tried to review the flight log.
However, I get the message: “log browse will not function correctly without FMT messages in your log” and I cannot view the log.
The file size is not zero, so it seems that something was recorded.
I will attach the crash log file below.
Below that is another log from the same day, recorded before the crash, which can be viewed normally.
I’m suspecting an ESC issue.
A few months ago, with the same drone, Motor 1 suddenly produced low thrust during a hover, and Motor 4 increased its output to compensate, but the drone crashed.
At that time, I didn’t suspect the ESC, so I didn’t replace it. Surprisingly, the drone flew fine many times afterward. However, it seems that the ESC had been having issues since then.
I think analyzing the log is necessary for an accurate diagnosis.
I would greatly appreciate help in analyzing the flight logs, and any possible theories regarding the cause of the crash are welcome.
Thank you so much in advance.
