Dear all & DJI, what is causes vortex ring state in drone flight ? Any practice or action to avoid this ? This is so scary..... Thanks.

It's not scary at all.
Vortex Ring State is something from back in the days of the Phantom 2.
Clever design means that your Phantom won't be affected by VRS.

Thanks labroides@yah... hope the current design of P3A will not be affected by the VRS.. but the bad, I just saw on youtube that P4 fall from alt. 500m and it suppposed to be caused by the VRS... Hope I am wrong

labroides@yahoo Posted at 2016-8-6 11:56
It's not scary at all.
Vortex Ring State is something from back in the days of the Phantom 2.
Clever ...

hi

Not true at all, vrs is possible to all helicopters/quadcopters/multicopters even the full size helicopters/chuncucks that the army uses. I have pasted in2 videos that explain about VRS and how to notice it and how to avoid.






thanks

As mentioned above, it can occur and I have tested this on my P4 by bringing it straight down and as the "legs" start to wobble, then slow it down and move forward.

I never bring it straight down from high altitude, especially if there is cross wind, because if it starts going into VRS, and then a strong cross wind hits it, then the results are un-predictable (and I would not want to find out).  I usually start descending further out and I use both sticks to first bring it down and then land it; (I usually grab it though, I do not like to land it on sand, etc).

I also wonder what would happen is someone makes a mistake when the use a third party application to upload a mission, but they make a mistake with altitude ranges.  For example, let's say one point is set to 300' and the next one by mistake is set to 30'.  If the next location set to 30' is close to the prior location (300'), I am not sure what would happen.  I have seen videos of P4 dropping, and I always wondered if it's such operator error?   

I also wonder if there are safeguards in the firmware, which will not allow an altitude gradient, which the P4 can not handle?

It's a bit of a rarity on the P3 with it's 3m/s max descent speed. The P4 can do 4m/s descent in sports mode, might just be enough to get into VRS.

That said, I tend to do wide spiral descents on my P3S to remove the possibility of VRS ver happening.

Thanks guys for answer and do brainstorming... But, if we are not allowed to straightly descend the drone to avoid vrs, then why DJI designed RTH procedure to straightly descend the drone to the landing point? I never noticed before how fast dji RTH procedure descent speed is.. Maybe DJI expert should make it clear to help their pilot to avoid vrs... Thanks

I'm sure that DJI has made the preset auto-landing speed VRS-proof.

OrlyP Posted at 2016-8-6 15:35
It's a bit of a rarity on the P3 with it's 3m/s max descent speed. The P4 can do 4m/s descent in spo ...

spiral decent in a forward movements  does help/reduce the possibility of vrs.

MD_Icarus Posted at 2016-8-6 15:18
As mentioned above, it can occur and I have tested this on my P4 by bringing it straight down and as ...

hi

the videos of p4's dropping are more likely to be csc's from new/inexperinced pilots rather than vrs but vrs is more likley to happen when flying in high/cross winds.I have not seen the videos of the p4's you mention so unable to comment further, what was the conditions on the videos - calm/windy etc ? any links to these videos please. i can not personally comment on the p4's as i have a p3 pro myself.As mentioned in comments above also that spiral decents in a forward movement does help/reduce the chances of vrs.

TechReviews Posted at 2016-8-6 03:51
hi

Not true at all, vrs is possible to all helicopters/quadcopters/multicopters even the full s ...

Aloha Tech,

     Labroides is actually right on the money here.  If you compare the motor placement between the P2 V+ v.2 and the P2 v.3, you will notice a change in angles of the props.  This distorts the column of air moving in the same downward direction as the Phantom that causes VRS.  The P3 series increased the angles slightly and showed it in the manual and then the P4 was an entire reconstruction of the design for new flight dynamics.

     Your top video is the one I used to get VRS for quadcopters included in WikiPedia, both mentioned in the "full" helicopter page and on the quadcopter page.  You can go into the back discussion pages and you will see my moniker and the discussion.  

     There are other flying issues that mimic VRS that many fliers confuse for VRS.  But, VRS is a specific condition and there are specific ways to get out of it as noted in the first video.

Aloha and Drone On!

MD_Icarus Posted at 2016-8-6 04:18
As mentioned above, it can occur and I have tested this on my P4 by bringing it straight down and as ...

Aloha Icarus,

     The P4 does have firmware that specifically addresses Vortex Ring State.  That firmware started with the latest updates to the P2 V+ and have been adjusted for every model since to address this issue.  I have failed to put a P3 or P4 into a vortex ring state, and believe me, I have tried.

     Many fliers get VRS confused with other wind and air states.  VRS is a specific condition involving descending too rapidly through your own downwash column.  As you can imagine, it is impossible to enter VRS with a vertical descent in a crosswind.  It is the same as if you are flying laterally, constantly flying out of your own downwash.  And if you are in a VRS, say with an early P2 V+ using early firmware and it starts to wobble, you have to move sideways to get out of the downwash column.  VRS can also occur if you enter your own downwash column that is at an angle due to light winds at the same angle as the downwash column.

     The top video is one of the few I used to get VRS for quadcopters included in WikiPedia, both mentioned in the "full" helicopter page and on the quadcopter page.  You can go into the back discussion pages and you will see my moniker and the discussion.  

Aloha and Drone On!

OrlyP Posted at 2016-8-6 04:35
It's a bit of a rarity on the P3 with it's 3m/s max descent speed. The P4 can do 4m/s descent in spo ...

Aloha Orly,

     The modified descent rates in combination with the modified prop angles of P2 v.3, P3 and P4 (you can see it in the manuals), are parts of the solution DJI came up with to manage VRS.  I have tried to put my P3P and P4 into VRS and failed each time.  But, I still like your wide spiral descents because they are the last bit of fun you get to have before you land.  

Aloha and Drone On!

andreaindra Posted at 2016-8-6 05:19
Thanks guys for answer and do brainstorming... But, if we are not allowed to straightly descend the  ...

Aloha andrea,

     If you compare the motor placement between the P2 V+ v.2 and the P2 v.3, you will notice a change in angles of the props.  This distorts the column of air moving in the same downward direction as the Phantom that causes VRS.  So, labroides is right on the money here.  

     The P3 and P4 do not have a problem with Vortex Ring State.  DJI modified the descent rate and prop angles to manage VRS.  You can see it in the manuals.  I have tried to put my P3P and P4 into VRS and failed each time.  

     The top video Tech posted is one of the few I used to get VRS for quadcopters included in WikiPedia, both mentioned in the "full" helicopter page and on the quadcopter page.  You can go into the back discussion pages and you will see my moniker and the discussion.

     There is a little more information in the other posts addressing the VRS concerns.  RTH stays within the firmware limitations DJI created to manage VRS so vertical descent is not an issue for RTH.

Aloha and Drone On!

MD_Icarus Posted at 2016-8-7 00:18
As mentioned above, it can occur and I have tested this on my P4 by bringing it straight down and as ...

"I never bring it straight down from high altitude, especially if there is cross wind, because if it starts going into VRS, and then a strong cross wind hits it, then the results are un-predictable (and I would not want to find out). "

If you were going to encounter VRS, it would be in still air rather than crosswinds.
With an aircraft that is prone to VRS, the standard prevention is to avoid vertical descent and keep some forward movement while descending.
A crosswind has the same effect.

Like Cetaman, I have tried many times with vertical descents from height.
And even in still air I have not been able to induce VRS in a P3.
I have also never heard of anyone else encountering VRS in their P3.
The combination of the 3 m/sec limited descent speed and offset motor angles effectively prevent VRS in a Phantom 3.

MD_Icarus Posted at 2016-8-7 00:18
As mentioned above, it can occur and I have tested this on my P4 by bringing it straight down and as ...

"I never bring it straight down from high altitude, especially if there is cross wind, because if it starts going into VRS, and then a strong cross wind hits it, then the results are un-predictable (and I would not want to find out). "

If you were going to encounter VRS, it would be in still air rather than crosswinds.
With an aircraft that is prone to VRS, the standard prevention is to avoid vertical descent and keep some forward movement while descending.
A crosswind has the same effect.

Like Cetaman, I have tried many times with vertical descents from height.
And even in still air I have not been able to induce VRS in a P3.
I have also never heard of anyone else encountering VRS in their P3.
The combination of the 3 m/sec limited descent speed and offset motor angles effectively prevent VRS in a Phantom 3.

Aloha everyone

I am so impressed with you guys. Now I really confidence to start flying again ! I have had hundreds of flight of my P3A but keep learning is the best way to fly safe right

Techreviews, this is the link : https://youtu.be/iLGRmnqmcWA
Please leave your analyze here Bro !!

Thanks guys and Drone on !!

There was another video here about a month ago, but I can not find it.  The P4 was flying around a mountain and it started descending and it then fell.
I will search for it again.....

I was referring to the P4 descending fast, then a sudden cross wind hits it.  I fly in areas where I start with 3-4 mph winds, and then I get a 20 MPH cross wind gust.  I think this is what happened to the P4 in the video posted here about a month ago.

MD_Icarus Posted at 2016-8-6 18:05
There was another video here about a month ago, but I can not find it.  The P4 was flying around a m ...

Aloha Icarus,

     Yes, that is a problem but it is not VRS.  I think the name for that is a Shear Wind.  Airports have detectors for that because it is such a problem.  And somebody crashed the other day due to one (manned aircraft).

     Just like the VRS problem with WikiPedia, it is hard to get full size aircraft enthusiasts to recognize that those of us who fly micro drones experience the same atmospheric problems.  Shear winds are a problem for micro drones.  Here in Hawai'i we have problem areas, but in very large land masses like the Mainland US and Australia, UK, Europe, etc. shear winds can mess you up just due to temperature differences of land, air and combinations of it all besides the effects of land mass configurations.

Aloha and Drone On!