Does the data rule out vortex ring state?You were rather quick there to get airborne, didn't have enough strong sats ... got the HP eventually, but on the other side of the house along side with the driveway.
The Mini were then later battered in harder winds on it's highest altitude above the trees, this produced alot of wind warnings & messages about max power load reached.
Messages:
View attachment 93613
It was an uncommanded descent in the end though ... but this time without the characteristic up pitch. I sincerely get a picture of a tired & exhausted Mini no longer wanting to fly
After the negative throttle at 559sec it continues to descent even though both positive throttle & elevator are applied. Would have been nice to see the DAT log also ...
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Unfortunately DJI will most likely say it was Pilot error as that is what they say most of the time, even when it can be proven from the data and eyewitnesses that it was not. as you might have gathered I have a very low opinion of DJI Care Refresh and Customer Support and not without good reason. DJI produce great products. If only their Customer Support was up to the standard of their products.Short flight in my garden with my 3 week old MM - no damage or issues on the previous 20 or so flights. On this flight I started a descent but when I tried to level out it failed to respond to left stick input until it hit my pond...
Details are in the attached TXT, but in summary:
9m 17s: I had 55% batteries holding at 31ft altitude and commanded a descent
9m 20s: Altitude 21ft and left stick back to neutral
9m 21s: Altitude 14ft and descending rapidly with stick still neutral
9m 22s: Left stick full up as I realise what is happening but MM still descending at ~8ft/sec
9m 23s: Altitude negative as the MM hits the pond
In hindsight I should be careful about descending over water, but I don't understand why there was no response to my input at 9m 22s... is there any other analysis I can do to try and understand why?
Thanks, Phil
When it was descending, was it wobbling? (Vortex ring state is also known as the Wobble of Death.)Short flight in my garden with my 3 week old MM - no damage or issues on the previous 20 or so flights. On this flight I started a descent but when I tried to level out it failed to respond to left stick input until it hit my pond...
Details are in the attached TXT, but in summary:
9m 17s: I had 55% batteries holding at 31ft altitude and commanded a descent
9m 20s: Altitude 21ft and left stick back to neutral
9m 21s: Altitude 14ft and descending rapidly with stick still neutral
9m 22s: Left stick full up as I realise what is happening but MM still descending at ~8ft/sec
9m 23s: Altitude negative as the MM hits the pond
In hindsight I should be careful about descending over water, but I don't understand why there was no response to my input at 9m 22s... is there any other analysis I can do to try and understand why?
Thanks, Phil
I ask this in a spirit of pure ignorance and enquiry. If the aircraft manages to achieve initial takeoff and climb, then the props are presumably undeformed. So is the deformation something which occurs during flight, exacerbated by sustained high rotational speeds making the prop blades deform to a finer pitch due to air pressure against the lower surface from leading to trailing edge?
I'm thinking along the lines of minimising full throttle operations - could that mitigate or delay the onset of deformation?
Does the plastic the props are made of have any "memory"? I know nothing about plastics, do they fatigue like some metals? Would some sort of periodic replacement schedule?
I guess the initial deformation would be at the tips where the pressure is highest and the material the thinnest? Do the motors have enough headroom (sorry, don't know the technical term) in terms of RPM to allow, say, snipping a few mills off the prop ends?
As a personal anecdote, years ago I used to race Control Line model planes. We used to make our own CF props by using a commercial, inferior-materials, plastic prop to make a mold. Our shed-made props were turning well over 30,000 rpm in flight. It can't be too hard.
Mike
They are likely deformed for the entire flight. In the logs that have been posted of this behavior, one or more of the motors is typically close to maximum, but the props are more effective when they are not descending into disturbed air - i.e. when they are climbing or moving laterally. When they do start to descend they seem to lose lift.
Wow! When will DJI fix this bug? I have a new one from yesterday almost crashed because of it!Short flight in my garden with my 3 week old MM - no damage or issues on the previous 20 or so flights. On this flight I started a descent but when I tried to level out it failed to respond to left stick input until it hit my pond...
Details are in the attached TXT, but in summary:
9m 17s: I had 55% batteries holding at 31ft altitude and commanded a descent
9m 20s: Altitude 21ft and left stick back to neutral
9m 21s: Altitude 14ft and descending rapidly with stick still neutral
9m 22s: Left stick full up as I realise what is happening but MM still descending at ~8ft/sec
9m 23s: Altitude negative as the MM hits the pond
In hindsight I should be careful about descending over water, but I don't understand why there was no response to my input at 9m 22s... is there any other analysis I can do to try and understand why?
Thanks, Phil
Thanks!!Because you have Java 32 bit and it needs 64 bit! Go to the java download page and manually and install Windows Offline (64-bit) , then retry.
I can't win... it only reads .dat files? No CSV or txt?Because you have Java 32 bit and it needs 64 bit! Go to the java download page and manually and install Windows Offline (64-bit) , then retry.
I can't win... it only reads .dat files? No CSV or txt?
It's not a Mac, it's windows, but I figured it out. Can I delete the DA files off the phone or do I need to leave them?On a Mac it won't convert txt logs because that requires the Windows executable TXTlogToCSVtool. @BudWalker explained that, and the workaround, in post #27.
It's not a Mac, it's windows, but I figured it out. Can I delete the DA files off the phone or do I need to leave them?
Is it possible the flexibility of the arms to play a role in the uncommanded descents? I mean if the arms are flexible that would make the propellers flex too and change the AOA.
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