Phantom 3 Standard Spiral Crash

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Well I had my first crash yesterday at my Dads farm flying my standard yesterday.Luckily she never crashed hard and there is no apparent damage.It was over 5000 ft out over farm land for a bit then brought her back within eyesight 1600 ft range and started to get Strong Interference Detected multiple times.The closest thing metal was a steel barn about 125 feet behind me. Be careful when flying long distances and RTH: Heading alignment warnings.Hardly no warning when it was over 5000' all the warning started at 3000' and under..Later the drone started a downward Spinning Spiral and during this downward plunge I had no control whatsoever.The props were still spinning since it never fell straight down like a rock,not sure if a motor overheated,maybe one motor overheated and quit.Would that cause the downward spiral.I dont think it would fly with just 3 props spinning.I was lucky where it came to rest.On the edge of a bush the video shows it scraped some big tall maple tree leaves and I found it upside down on some tall 3 ft high grass and weeds.No body damage to drone or props or prop guards.I flew it later for a couple min close to the ground to test it quick with a fresh battery and all props spin ok since it was getting dark out.The only thing I did this flight that was different was a couple days ago I rolled the firmware back from the latest down to P3C_FW_V01.07.0090 to try it out since I herd people say it worked better than the latest up to date firmware.Shiite,now I am thinking if maybe it was the older firmware that caused this.Anyone have any ?Ideas? on my Downward Spiral.
 

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How can I tell if a motor overheated and a prop quit spinning.Would a prop shut down cause the spiral downfall.It was very hot yesterday,Humidex of 39 cel yesterday when I was flying.I was thinking the next time I go to the farm to fly I will lift off and let it hover for the entire life of the battery and see if a motor shuts down at a height of 2 feet in the sandy soybean field.If a motor is faulty and quits it should not damage anything at a 2 ft height,or should I take the props off when doing this test and just let the motors rev until the battery runs down to check for a faulty motor.
 

Fly Dawg

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How can I tell if a motor overheated and a prop quit spinning.
You can't with a standard, unless you look at the aircraft .dat file. Are you 100% certain that all the props were intact and undamaged?

You spiral began after you released the elevator, issued a slight yaw command then immediately gave full throttle down. Typically this would be a lost prop. However, generally speaking the aircraft will come down but will not spiral out of control as it appears was the case here. It could very well be a motor issue and/or the ESC. The aircraft .dat file unfortunately on the Standard does not record the motor data other than the PWM, but that could give an additional clue. You can see what the aircraft was doing during the time I mentioned below.

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Yep..After I got it and walked back to to shop/barn and guzzled a couple beers I put in a fresh battery in and did a quick 2 min test flight at low level and everything was fine and dandy with the drone.It was a 2 min low level flight and it was getting dark so I called it quits.
 

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Fly Dawg

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Those are not aircraft files. In fact, they match nothing. You will need to download the file from the aircraft itself and upload that to a shareable site such as google drive, drop box....etc.....they are too large to direct upload. See the link below for instructions. Once you have the files, place a link back here to that.

Retrieve P3 Dat
 
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By the way Thanks for your Help..I appreciate it Big Time..I did what you said and I have 4 FLY DAT files from yesterdays Flight Data Mode ranging from 70mb,84mb,300mb and 25 mbs.Should I upload all 4 dat files or just the big one.
 

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You need FLY 323.........
 

Fly Dawg

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I have to admit that I have not seen a data set such as this one. It certainly appears to be a lost prop condition. The only other thing I can think of is an ESC issue of some sort. Maybe @sar104 and/or @BudWalker can shed more light on this one.

PWM1.png
 

sar104

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I have to admit that I have not seen a data set such as this one. It certainly appears to be a lost prop condition. The only other thing I can think of is an ESC issue of some sort. Maybe @sar104 and/or @BudWalker can shed more light on this one.

View attachment 112641

Look at the oscillation period (700 ms on attitude, 2 s on yaw), the relatively narrow range of pitch/roll excursion (± 40°) and the relatively slow descent speed (4 m/s). Haven't seen that for a long time. Looks like classic vortex ring state descent.

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Looks like classic vortex ring state descent.
That is exactly what I was thinking, but thought that had been eradicated. And the fact that I have not seen the data from such.
 

sar104

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That is exactly what I was thinking, but thought that had been eradicated. And the fact that I have not seen the data from such.
It was a thing with the P2 - very easy to trigger. The P3 geometry was tweaked to reduce it. I guess there might be some specific fault in a motor that could cause similar effects, but I've never seen that happen.
 

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@NIK1 ... As provided by @sar104 above, it looks like there could have been a vortex state occurring. Going by the fact that you mentioned the aircraft flew fine afterwards, there may or may not be a motor issue. I am going simply by the RC inputs as shown below as to a cause and effect. Your inputs being so close together ( >2sec for all 3 ) that "may " have caused the unrecoverable spiral to occur, especially the down throttle immediately after releasing full elevator. The spiral began slowly, then became constant at 360 degrees every 2 seconds until impact.

Spiral.png
 
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Thanks for checking all that data for me..I would not know what to look at or where to begin with this.What did you mean by the inputs being so close together ( >2sec for all 3 ) that "may " have caused the unrecoverable spiral to occur.Plus is there anything I should test or watch out for the next time I do any long distance flying at any given height.Here is a Video of the Flight that was recording when the drone went on the Wonky Spiral..The spiral starts at 0:4:23 in the video..
Drone Spiral.MP4
 

Fly Dawg

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What did you mean by the inputs being so close together ( >2sec for all 3 ) that "may " have caused the unrecoverable spiral to occur.
What I meant by the inputs are the fact that you were flying at full forward elevator, you applied a slight rudder then immediately gave full throttle down. When you release the elevator the aircraft will pitch up slightly to stop. You did not allow the stop to occur before issuing the full down elevator, which could have contributed to the "presumed" vortex effect. Once that starts, it is almost impossible to recover from. You can see the inputs in the graph above and they are very close together, almost simultaneous in fact. There is not much you can do at that point. IMO, I would have issued full aileron one way or the other to attempt to escape the vortex. This is a very rare occurrence but it does happen. All rotary aircraft are subject to that to some degree, although it is much less likely at present.
 
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Right on I see what you mean now..I will try to be more gentle with the joystick control's when changing direction and altitude from now on.I think video game controllers have my fingers kind of trigger happy with very fast movement.Have to slow down when drone flying or the next time I might not be so lucky..Next time I am going through Georgia on my way to Bike Week in Daytona like I do every year for the past 20 years I will drop you a case of some good Canuck Brewskis for your time and effort.And of coarse I will help you drink some...Eh.
 

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Interesting analysis FD.

VRS (i.e.settling with power) can theoretically be escaped with pitch, roll or both if enough altitude is available.
Yaw is useless and throttle-up (inc. Collective) exacerbates it.
 

sar104

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Interesting analysis FD.

VRS (i.e.settling with power) can theoretically be escaped with pitch, roll or both if enough altitude is available.
Yaw is useless and throttle-up (inc. Collective) exacerbates it.
There was plenty of height to work with, but no sustained effort to escape VRS laterally - if that's what it was.

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