- Joined
- Dec 7, 2018
- Messages
- 8
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- 9
- Age
- 68
On my second Mavic 2 Pro now. Before I mention what I think was a VRS wobble today using RTH, I wanted to mention a fatal series of errors that cost me my first Mavic 2.
Christmas Eve I tried to fly a Litchi mission that would have taken the Mavic 2 Pro under a fairly low bridge over a slough/channel here in Portland (for locals this was the SAvie Island Bridge). I lost sight of the MAvic 2 against the grey trees as it was passing under the bridge deck. It aaprently slammed into teh bridge deck, broke of a blade (or two) and the last thing I saw was its gyrating arms as some weak afternoon sun glinted off the aircrafts and the mind-numbing splash as 1300.00 worth of aircraft hit hard in 20 feet of muddy, slow moving water under the bridge. Although I was flying a Litch mission I am pretty sure this was NOT Litchi's fault. My best guess is that I combined several mistakes to cause this crash. 1) accidentally assigned my C2 switch to FVP mode and 2) had previously enabled 30º up camera and then, 3) accidentally — when I lost sigh of the drone — decided to look UP with the camera to see how far under the bridge I was, and how far down (close to the water) I was (in the accidentally triggered FVP mode), I flew it UP into the bridge deck! Stupid, stupid set of mistakes.
However, like the Arlo Guthry song Alice's Restaurant says: "...but that's not what I am here to talk to you about!"
With my second Mavic 2, and a lot more caution, I have been shooting a few Hyperlapses. On the way back from shooting a Hyperlapse I experiences a RTH landing snafu. Not sure what I was seeing. I know what a VRS (Vortex Ring State) is. I do not think this is what happened. It was a cool sunset (about 40º F at the time). I hit RTH from about 300-400 meters out at about the RTH height I was sat (200 feet or so). It made it overhead, and began descending. At perhaps 15-20 meters the craft started gyrating around what should have been the descent vector (Y-axis), kind of like a top. I watched for a few seconds in a mixed state of confusion and fear, then I did what I would have done if I'd known I was experiencing a Vortex Ring State issue: rapidly switched to ATTI mode and flew a little bit away from the center of the descent spiral. This worked, and then I brought it back and landed manually.
Does anyone want to hazard a guess HOW this happened and if there is a way to avoid this? I could have been really bad if I had been descending between some trees or into a goths space between houses or something.
I know VRS is supposed to cause a rapid descent, and I know that this can be accompanied by wobbling, but this was more like a gyro issue, as I I had a heave weight suspended below the centerline of the bird and the gyro was trying to compensate and suddenly got locked into some sort of CoG feedback oscillation.
Anyone have any ideas? Thanks!
Christmas Eve I tried to fly a Litchi mission that would have taken the Mavic 2 Pro under a fairly low bridge over a slough/channel here in Portland (for locals this was the SAvie Island Bridge). I lost sight of the MAvic 2 against the grey trees as it was passing under the bridge deck. It aaprently slammed into teh bridge deck, broke of a blade (or two) and the last thing I saw was its gyrating arms as some weak afternoon sun glinted off the aircrafts and the mind-numbing splash as 1300.00 worth of aircraft hit hard in 20 feet of muddy, slow moving water under the bridge. Although I was flying a Litch mission I am pretty sure this was NOT Litchi's fault. My best guess is that I combined several mistakes to cause this crash. 1) accidentally assigned my C2 switch to FVP mode and 2) had previously enabled 30º up camera and then, 3) accidentally — when I lost sigh of the drone — decided to look UP with the camera to see how far under the bridge I was, and how far down (close to the water) I was (in the accidentally triggered FVP mode), I flew it UP into the bridge deck! Stupid, stupid set of mistakes.
However, like the Arlo Guthry song Alice's Restaurant says: "...but that's not what I am here to talk to you about!"
With my second Mavic 2, and a lot more caution, I have been shooting a few Hyperlapses. On the way back from shooting a Hyperlapse I experiences a RTH landing snafu. Not sure what I was seeing. I know what a VRS (Vortex Ring State) is. I do not think this is what happened. It was a cool sunset (about 40º F at the time). I hit RTH from about 300-400 meters out at about the RTH height I was sat (200 feet or so). It made it overhead, and began descending. At perhaps 15-20 meters the craft started gyrating around what should have been the descent vector (Y-axis), kind of like a top. I watched for a few seconds in a mixed state of confusion and fear, then I did what I would have done if I'd known I was experiencing a Vortex Ring State issue: rapidly switched to ATTI mode and flew a little bit away from the center of the descent spiral. This worked, and then I brought it back and landed manually.
Does anyone want to hazard a guess HOW this happened and if there is a way to avoid this? I could have been really bad if I had been descending between some trees or into a goths space between houses or something.
I know VRS is supposed to cause a rapid descent, and I know that this can be accompanied by wobbling, but this was more like a gyro issue, as I I had a heave weight suspended below the centerline of the bird and the gyro was trying to compensate and suddenly got locked into some sort of CoG feedback oscillation.
Anyone have any ideas? Thanks!