If I'm an idiot, then there's an easy fix so as to not have this happen again. (hours of searching forums, and other videos, I've seen nothing else like this)



Although there's details in the YouTube description I'll post here as well.

Hardware: Phantom 2, Zenmuse H3-3D, Hero3 Black, AVL58 Tx, iOSD, ND filter
Location: Wilkerson Pass, CO 9,400'alt. -  flying only ~20'AGL @ time of crash
Weather: 0-5mph headwind, ~35f degrees
Battery status: Phantom 2 @~60%, Tx @~85%
Satellites: 12 & flying in GPS mode
Current Firmware, recent compass calibration, no transmission lines/antennae/other potential source of electrical interference, standing only ~15' behind video start point.

Control input during video: Full forward throttle (right stick only), upon slight descent - ceased input on control, immedite rapid descent primarily after forward motion stop, countered unsuccessfully with full vertical throttle during descent (left stick only, in hindsight I understand this was a bad idea if VortexRingState), followed by senseless shaking of controler and singular token obsenity (not in video, there is no audio).

Thoughts, critiques, anything,,,?
It's better than a flyaway, but seriously scares me considering places I've flown and possible reprocussions when there's no warning or known cause.
Thanks!!

How far out was your Phantom from you when this happened? Did you get a screen capture from your display after the crash with the last transmission data? Any chance you can plug your Phantom in and check your battery for verification of condition, charge level etc? Did you have RTH if low battery level reached (I did see your level you posted but curious)...did you calibrate your compass at the location you were flying?
I cannot see anything in their suspect to me but more data is better and hope the Phantom is o.k!
You were not that high off the ground so I can see reaction time would not have left you much to have tried shutting off the controller to enable auto RTH after you tried the throttle up and I cannot fathom how at that altitude off the ground with minimal wind that VRS would have occurred especially as you had some forward momentum.
And great write up on all that happened and far from an idiot with that detail!

That's not VRS, as it was going forward.  It looks like wrong stick input as you slowed with the right stick pulling left stick down instead of pushing up to gain height. Easily done.

UAVForum.UK Posted at 2015-3-13 01:33
That's not VRS, as it was going forward.  It looks like wrong stick input as you slowed with the rig ...

He stated full vertical throttle, I presume that he meant left stick up, not down!?!Now maybe on the slight descent just prior there was a gust over his Phantom that proceeded to throw it downward that combined with the slight descent that regardless of what he did due to his flying height off the ground the Phantom did not have enough time to react to the RC...

Northofthe49th Posted at 2015-3-13 01:37
He stated full vertical throttle, I presume that he meant left stick up, not down!?!Now maybe on th ...

I know Glitch said left stick up which is why I said it's an easy mistake to make, especially when so close to the ground. It looked to me like the machine came down fast but controlled i.e. it was not tumbling or dropping like a stone which it would in VRS.
Anyway Glitch I hope your machine was not too badly damaged and I wouldn't beat myself up about it if I were you. It'll make you a better flyer in future.

Hi, that doesn't look like VRS to me. It seemed more like a rapid descent- it looked too controlled, however it was low to start. Sorry I can't help- just an opinion.
Cheers!
Rod and the cheshire cat.

Carefully looking at the video you also yawed "right" very slightly at the last moment. It's inconclusive, but possible pilot error.

Northofthe49th Posted at 2015-3-13 01:17
How far out was your Phantom from you when this happened? Did you get a screen capture from your dis ...

Thankfully it was undamaged, and I know my battery level wasn't a normal issue because after picking it up and dusting the snow off I flew it back to my car while I was walking along side it listening for any unusual noises.  It was in the air for ~3min more after the crash before I shut it down with ~30%.

As for distance, it was only about 50m away. Basically the distance you see it fly in the video started with it 5m away.

It just felt like it was "tired of flying" and spooled down. Thankfully it wasn't high enough to build up speed as the power seemed to drop off. Everything happened so quick I couldn't tell if it responded to the increase in throttle or if it was unresponsive. Even the audio in the video wasn't clear. (and as soon as I knew it was on the ground, I initiated a shut down so to prevent further possible damage)

UAVForum.UK Posted at 2015-3-13 02:30
I know Glitch said left stick up which is why I said it's an easy mistake to make, especially when ...

You're right, other than the accelerating speed of the drop everything about the descent felt controlled which was my second reason to doubt VRS (first was that I was flying forward), however I do know with certainty that I didn't accidentally descend with erroneous input.

I genuinely wish that were the issue since that can be fixed simply with more practice. However the drop was increasing in speed much faster than I could mange with an intentional descent.

The initial reaction to the slight drop in trajectory was zero input rather than vertical thrust, however it was immediately clear that it wasn't going to stabilize in a hover as the descent was immediate and it was only then I tried full vertical throttle. (Part of how I know it wasn't an accidental reverse input is that I've had a decent amount of time logged and have developed the reaction of full vertical thrust and zero directional input for the greatest probability of clearing an unexpected obstacle/event, except when flying in narrow canyons where directional correction is the only good option given drift w/o GPS lock)

Thank you for your thoughts, and I'm not insulted in the least as that's probably what I'd have suggested to someone else posting a similar looking video. Actually ~2min prior to that my significant other was flying it for the first time, and although it was thankfully much higher, it seemed to descend slower, which was probably pilot error swapping left/right input. I'd say that was certainly erroneous input if it weren't for this happening to myself minutes later.

tonyphantom147@ Posted at 2015-3-13 07:13
Carefully looking at the video you also yawed "right" very slightly at the last moment. It's inconcl ...

Good catch, I actually hadn't noticed that. However that's probably just a slight error on the stick from my desperate attempt at recovering with full vertical throttle. A couple times I've had to re-do rising shots because of minor yaw input when I wasn't as precise with my control.

rod Posted at 2015-3-13 06:28
Hi, that doesn't look like VRS to me. It seemed more like a rapid descent- it looked too controlled, ...

That's what I'm afraid of. I wish it were VRS so at least I could have an idea of what to look for to prevent it in the future. Although it looks controlled, and there are certainly worse descents, I fly in several other areas where this would be catastrophic.

was it windy at all?  i ask because ive had this happen to me where a wind gust crossing below my props caused a near immediate 10ft drop in altitude and 'throttling up' cause more prop wash which i believe actually made the problem worse than better.  my estimate is that if i had not throttled up, the wind gust below the craft might have only caused a 2-5ft drop and my 'throttle up' reaction exacerbated the problem and made it 'act like' VRS in that it dropped.  is was not like VRS in that it didnt wobble, it just lost lift, which is a component of VRS but not the whole thing.  

while the situation i describe is certainly not VRS, it has similar aspects.  it all has to do with the wind below the prop.  once you factor in prop wash, wind (both speed and direction), etc, i think there are situations where you can lose lift momentarily and when you are only a few feet off the ground (like i was) there is no time for the factors to clear (the gust to stop, the ability to move sideways out of the wash, etc).

certainly no evidence this is the case for you but sharing my experience because it defn had similarities.

That's a hard landing not a crash.  This is a crash (skip ahead to :30 second ifg you just want the crash):

HermosaDrones Posted at 2015-3-13 23:37
That's a hard landing not a crash.  This is a crash (skip ahead to :30 second ifg you just want the  ...

Ouch! I'm guessing that required at least a replacement prop or two, if not also a gimbal, body, etc...

I know I was very fortunate with mine, which although it was a relatively soft impact initially on the skids before flipping, it was still entirely devoid of intentional control. Anytime an aircraft ends up on the ground, upside down when all control input was meant to keep it airborne, I count it as a crash.

Some are just worse than others, like yours!

gnixon2015 Posted at 2015-3-13 23:04
was it windy at all?  i ask because ive had this happen to me where a wind gust crossing below my pr ...

Nope, nothing that would have impacted it such a manner, however it's good to hear stories of what others have experienced.