My Phantom V2 Vision (not plus) has performed perfectly since I bought it in the beginning of December. It has performed as DJI said it would, its always come home and I have genuinely had no issues with it at all. - until this afternoon, all was going well when the low battery fog horn started blasting out.  Red lights flashing it does this @ 15%, now I have my system RTH set to climb to 200ft and return to base (because of trees), however as it was virtually over my head about 50ft up I did not want this so I toggled switch 1 to atti and back to GPS.

Prior to cancelling return home I had noticed some instability in its decent, after I flicked the switch it went berserk and started to oscillate from side to side not responding to any control input.  It simply fell from the sky - rotors still spinning and was not like a stone, more like 3 times as fast as it should have done.  Frontally I was on a soggy field and the only damage was the camera fell off ripping out the gimbal wires (thats ok its done that before) and simply needed the connector pushing back together.

So does anyone know why this would have done happened - I had 12 sats locked and had been flying for about 15mins prior to the low battery warning.

I have my idea but wanted to know what you guys thought first.

Sounds like you got into the VORTEX.

yes, http://en.wikipedia.org/wiki/Vortex_ring_state

Yes and I think I know why.  I have  fitted some  propeller guards and a tracker holder.  I think the copter is now too heavy !  I will weigh it and report back, but I have noticed almost immediately the machine was not performing as good as it used to, slightly sluggish, slower to ascend and accelerate.

It still few very well though, I'll post a video of the footage the phantom took before the crash sadly the camcorder battery died - so no video of the phantom

Update Time,

Ok so I have found out what caused the crash.  To cut a long fault finding - long testing story short it turns out it was one of my motors that had a problem.

This motor had an intermittent slow down fault (mechanical) which caused the ESC to speed up the motor, the motor then freed its self causing an over spin condition.  Until fixed the copter would not fly without drifting uncontrollably just like many have reported during flyaways.

The Copter seems to develop a mind of its own as the onboard computer tries to compensate for it.  Strangely with the prop guards on the coper would fly darting around (not good), but without it would not fly at all.

I could hear a metallic grating (very quiet) along with the associated speed up and slow down, this was intermittent and totally random and not at all related to motor revs.

The Fix :- Believe it or not the cure was to tighten the two screws the you change when you fit prop guards,  mine are detachable which probably gave the affect of tightened up when inserted, hence would not fly when removed.

So this is one thing to check - make sure your motor screws have not loosened.

If think if you are flying at 15% battery you are asking for trouble. On my P2V+ I have to apply full power below 20% just to kept my Phantom hovering. I have only done that with the bird a foot or 2 off the ground to drain the battery.

Prop guards are a well documented reason for vortex ring crashes

Daninho Posted at 2015-1-22 03:42
Prop guards are a well documented reason for vortex ring crashes

Not to be rude but have you read what I just posted ?

JATO Posted at 2015-1-22 02:43
If think if you are flying at 15% battery you are asking for trouble. On my P2V+ I have to apply ful ...

No it was landing when it hit 15%
My phantom will take off and fly on 15% until it auto lands with no problems
I have documented the reason for the crash.

Umpa,
Part of that story sounds familiar..I too was 40-50' away from landing and then away she went! 160' is my RTH altitude..fortunately I have my battery buzzer come on at 30% I believe, so plenty of power for it to go up and come back down. Unfortunately on that evening a gust of wind grabbed it just as it got to my house height..and there it landed on my roof, safe and sound, two stories up.. Fortunately,10 min later with the ladder (by this time my wife thinks I'm nuts!...well, more nuts than she originally thought!) we are back on the ground and safe without any scars...
I too use the prop guards and they are a bit of a catch 22 with regard to performance (definitely less battery life and less speed), safety of the bird and the Vortex rings
I did not know you could cancel the fail safe, will have to try that in my field on the weekend...

In my case though the motor was a fault, thats what I'm trying to get across here.  In fact worse still is that the motor was actually fine after I tightened the machine screws, so by all accounts it might still be faulty and just waiting lol.

Remember the next day with a fully charged battery it would not take off properly so the screws must have loosened in flight.  My screws did not have thread glue.

Oh and just a heads up, I cancelled the auto return home low battery and not the auto land low battery.

I did not like the prop guards and keep reading reasons not to have them.  Gone!

Never had a problem with them, and make my Phantom easier to see in the sky.  They have saved my Props from ground strike on many occasions. I have flown with & without.

The prop guards serve a purpose.  They provide a safety mechanism for newer pilots.  Also if the bird is to be flown in close proximity where the chance of collision is a possibility.

VRS was not the cause of this issue blaming prop guards prematurely for this phenomenon isn't relevant.  
VRS happens with or without prop guards.  Proper descent profile is the way to reduce this phenomenon.

Gunny Huntarr Posted at 2015-1-22 23:51
The prop guards serve a purpose.  They provide a safety mechanism for newer pilots.  Also if the bir ...

I dont entirely agree with you. Prop guards make the drone more vulnerable for VRS. Aerodynamics and the flight behaviour is different with them on. I've read so many incidents where the phantom crashed with prop guards, but a lot less without. Obviously, as you mentioned, it's not the only factor but surely adds to it.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

Hey Markus I got a reminder that you replied here but it's not showing up.

Gunny Huntarr Posted at 2015-1-23 07:41
Hey Markus I got a reminder that you replied here but it's not showing up.

Half of these entries for the posters are missing Gunny.  I'll have to admit, when DJI fixes something they do a great job,,,,,NOT!

Gunny Huntarr Posted at 2015-1-23 07:41
Hey Markus I got a reminder that you replied here but it's not showing up.

A lot of posts are not showing.  When DJI fixes something, they do a good job, ,,,,, NOT!

i replied too, like 10 times.  it isnt working, i doubt this one will either....
hey it worked... so here is an edit (what i tried to reply to gunny earlier)...

good point gunny.  i use them and today i hit a tree limb (i was testing the HL 'go in a circle using left roll' feature) and i overlooked the branches on a tree that were hard to see.  it was CLEARLY my error and CLEARLY something that an experience pilot could avoid WITHOUT prop guards, but my bird bounced off of the tree limbs and kept flying (at about 100 ft altitude).  no doubt that if i had hit that without them i would have a broken phantom right now.  

conversely, i plan to take them off soon but i agree with gunny that they do serve a purpose and have been worth the 'prop wash' and 'wind wing' issues that i have seen with them so far.

gnixon2015 Posted at 2015-1-23 08:23
i replied too, like 10 times.  it isnt working, i doubt this one will either....
hey it worked... so ...

All your other posts showed up, all at the same time.

ive had 15+ flights (every one with prop guards on), ive flown in high winds (10-12mph) descended straight down (not always i usually do the recommended lateral movement instead of directly down but did multiple straight down just to see how unstable the propwashVRS effect would be) and i know this is just my experience but the prop guards have had little to no effect on what i would call stable flying.

ill say this much tho, ive struck TWO THINGS (one was my house on my 2nd flight and the other was a tree limb i hit today) and without prop guards i would have a thousand dollars worth of plastic right now.

say what you want about prop guards (and as mentioned above i am planning on taking them off soon) but they do serve a very specific purpose and for that there is absolutely no reason people should shy away from the early on.  after all of my flights i can say that ALONE they certainly dont have a high chance of causing VRS.  for sure they are a factor (as is the descent rate, the wind, etc).

and to markus, ive read double digit number of threads about 'burnt out ESCs' from tipovers or hitting props on things 'at speed' which is way more than the number of threads ive seen where prop guards caused VRS.  again, not saying they cant or dont, just that if used properly they have some very strong up sides too.