info
lvl.3
Flight distance : 647034 ft
United States
Offline
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I have been thinking a lot about what happened during my I1 "flyaway" a couple of weeks ago, but it was not until this evening that I figured it out! I can conclude that my I1 did not appear to by definition experience a "flyaway." I finally obtained access to the flight log and the moment I reviewed the details of this flight, it was clear what happened. (sorry, I can not share video/logs due to an NDA on this project), but I assure anyone that I have nothing to gain from posting the findings of our investigation in to this incident.
So, here is what happened:
On the previous 2 flights, it is clear that the craft/compass direction is facing away from my launch location, however, on the third flight, the compass orientation is flipped 180 degrees at takeoff, so the I1 thought it was looking at me, not away from me. This means that although the craft is visually orientated normally, the flight controls were all reversed.
This also explains why I was unable to regain control when I switched to atti, as this only accellerated the rate at which I was compensating in the wrong direction on all inputs, as I was responding according to the visual orientation of the craft. I also assumed that RTH did not engage, but maybe it did, just a moment too late as Atti mode had already gained too much momentum for GPS to respond in time before impact.
What does this mean? We have added a new step to our preflight checklist that should ensure this never happens again. I have never included looking at the orientation bubble to determine preflight craft orientation, as this is not a feature present on any UAS that I have operated. I have always calibrated the compass before my first flight and gone from there. Without this experience, I would have looked at the craft/gimbal orientation feature and assumed that the craft needed to be in the air and get better GPS lock before the orientation corrected itself, and would have taken off. This incident has taught me that the craft/gimbal orientation feature is actually correct and this should definitely be a preflight check.
I wonder if any of the other "flyaways" would show that this happened. I have read other posts where people mention reversed controls, so maybe this is some kind of bug, I honestly do not know, but I strongly believe this is what happened in my case and it appears that at least my incident could have been avoided if I had looked for and trusted the orientation information on the screen.
If this is a bug, I hope DJI is doing something to fix it. In all of my years flying, I have never experienced a sudden full reversal of all controls, so this is certainly concerning, but looking at the facts, I am certain my situation could have been detected/avoided.
I hope this helps and saves someone from a bad day, I surely learned something from it.
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