I work in the field of rotary-wing aerodynamics and this video is an excellent example of how such low disk-loading (vehicle weight divided by disk area of all rotors) rotorcraft can get into VRS at much lower rates of descent than piloted aircraft. Thanks for posting!
Thanks so much for this valuable VRS tip Q101! This just happened to me with my new XK X252 a couple of days ago. I'm still a novice, not to flying RC or real planes, but RC drones. I was out flying the X252 when I realized it was getting a bit high. I immediately pulled the power back some and it went into a vertical descent. Almost immediately it began wobbling badly on the way down. I added power and luckily I still had plenty of altitude so it smoothed out and I was able to fly it out of the descent and the story had a happy ending. In fact, I thought it was just the X252 not being very stable since it is a little squirrelly being a high performance brushless 3D quad. Now I know I was at fault and will avoid vertical descents in the future. Thanks again! I wish I had run across this tip earlier.
I wish more videos for drone beginners would mention this, because it seems like a common problem, something you need to watch out for on _every_ descent.
Thank you Quad 101. I've been into RC for years different types and just got addicted to quad platform. It has been AMAZING! Today during a flight my CX-20 went into VRS and fell like a stone, but was able to catch in ground effect and do almost no damage. This video will inspire me to train for VRS issues in the future. Could have been a very costly day for copter,gopro, and fpv transmitter. Keep the education coming our way. Shon
Your tutorials have been spot on! Being an advanced beginner, my two "big birds" are the Syma X8C and the Wiltoy 686. Applying what I've learned from you, it's made quad flying a much more enjoyable experience. Thank you!
Thank you so much for this info! This should be required reading with all quads! My DJI entered VRS at 60 feet yesterday luckily over a soft field. This is a very dangerous state to enter into and too many pilots are not made aware of this issue and they fly over people before knowing that this is an issue. Thank you much my friend, you got my subscription!
Excellent again. I sure have learned something. THANKYOU once again for a great explanation of Vortex ring state. Now I know why my quad woobles on descent. Just need to apply some forward pitch during a rapid descent. Sandy
I'm a full scale helicopter pilot- vortex ring state (vrs) will only occur descending vertically in calm/no winds but also moving forward slowly and descending rapidly/steeply with a tail wind (tailwind blows vortices into the path of the props)- if you are descending vertically rapidly with a stiff wind- the vortices are likley to be blown out of the descent path and less likely to create vrs- if you get into vrs- don't add more throttle (it will exacerbate vrs)- instead gain airpseed (forward, but altenately backwards or laterally- best move upwind) to get out of the vortices and if altitude permits lower throttle to reduce vortices- vrs in helicopters is very dangerous and must be avoided at all costs- for helicopters like the robinson R22- 3 things need to happening at the same time for vrs to occur- at least 10-20% power applied, airspeed (not groundspeed) less than effective translational lift ETL (less than around 15-24 knots) - note- you can have airpseed just hovering on a spot in winds greater than ETL speeds and third a descent rate of greater than 300 feet/minute- don't know how that translates to multirotors/rc helicopters in general- but food for thought..basically avoid vrs by descending slowly (slower vertical speed, descending into wind (not a tail wind),if possible with some forward airspeed and not too steep an approach- IGE for quads is probably less than a foot aboveteh ground- anything above a foot above the ground is going to be an OGE hover rwequiring more power- and hard to maintain on hotter, humid days - especially at higher elevations, where the air is thinner
that’s an outdated recovery concept that you mention. Look into the vuichard recovery technique (which wont work for quads as you need an anti torque rotor for it)
Well put; For multi-rotor, you don't have a swashplate / collective, I believe your best bet is to full throttle and full pitch together because you need the throttle to cause the pitch to heppen and it also could significantly change the angle of attack of blades relative to the vortices which I assume disrupts them. Full pitch forward would cause the multi-rotor to essentially fall forward translationally, across and downward, but with all your energy stored in the blades for lift once you exit the vortex which given sufficient altitude and thrust to weight ratio should recover itself in the manner this video demonstrates. Agree with pushing it upwind, will definitely recover better, but if there isn't much wind or you don't have time to think I would say just push forward immediately, most multi-rotors are low altitude when this happens, probably coming in for a landing and the time to react is very low. If you throttle down on a multi-rotor you decrease your RPM not your blade pitch, it is going to fall like a rock with no energy stored in your blades and a diminished ability to gain forward airspeed. In a helicopter you still have full RPM you have only reduced your blad pitch and then to move translationially out of it your cyclic will increase the blade pitch only where you need it (a pitch increase 90 degrees in advance to the opposite side of your intended direction), and at full RPM. Collective down and cyclic pitched on a helicopter's rotor will give you un-even lift on your disk which I wonder and this is just an assumption; if that could help to disrupt some of the vortex as well even before you move fully out of it. Makes sense for a helicopter to do it that way, but not a multi-rotor. My own experience with it; got caught out once, all of the other times I was able to recover from it just fine. I avoid vertical descents and fly like this video recommends most of the time. Interestingly I have built some coaxial multi-rotors X8 configuration and found that you can drop them really hard and they will self recover from the wobble with throttle alone, with propellers spinning in opposite directions, they don't seem to sustain a vortex for long. Particularly if you make the bottom prob spin at a higher RPM to the top one in programming. Large diameter props on low KV motors are very prone to VRS and should be landed like a fixed wing with some pitch or descended vertically at a very slow rate. Most that I have flown with a high power to weight ratio and decent quality motors / props etc can recover pretty quickly, an FPV drone or Mavic or something barely requires any thought given to this at all.. But if flying a large heavy lift drone with a decent payload or a cheap, underpowered one like in this video, be careful of VRS, you may not be able to power out of it in time.
Noticed some weird wobble when descending Q500+ today (maiden flight) so I stopped home mode and manually landed the quad slowly. I thought it's because of the wind but gut feeling tells me it's more than that. I then did some research and found out the "wobble of death" aka Vortex Ring State. Ended up with your video and I'd say it's the most helpful so far. Thank you so much!
Excellent demonstration !!! I was familiar with these effects in theory but have never seen them demonstrated so clearly. You have turned theory into reality and made it much more memorable.
I watched this video some time ago. Today it saved my Scout X4 with a camera and gimbal. I was at about 50 meters when it started to plummet. Though I was not descending it was turbulent and a gust may have initiated descent from hover into VRS. I recognized it and gave full forward thrust. After about 25 meter she recovered. I just wanted to say a huge THANKS!
Thanks so much for this video! I was flying in Slovakia last year and whilst bring it down from a high altitude it went absolutely mental for no reason (full throttle did nothing) and dropped rapidly for about 60 metres rocking violently before it settled a few metres above a tall tree (phew). I’d since been blaming the quad for the situation, but I now know it was a classic case of VRS caused by descending into powerful thermals (it had been a very hot day). I was lucky as I now believe the tree had dampened the turbulent air and saved my quad form smashing into the ground. After watching your great tutorial I’m now aware of the causes or VRS, how to avoid VRS and hopefully escape a future VRS situation. Many thanks again :-)
We had this happen on a Phantom 2 Vision Plus and the resulting hard landing busted the camera assembly and some other bits are looking rather sad and sorry. The model shop we bought it from told us about VRS and this is the best video I've found so far explaining the situation and teaching how to cope with it. It scared the hell out of us, so it's nice to know it's a somewhat common phenomenon.
That's so funny. I'm a total beginner, and just this evening I was flying my new Hubsan H502E. There were a couple of times I had to make a quick descent and it went to the ground in VRS just like you said in this video...except I had never heard of VRS and wondered what was wrong with the drone. Turns out this particular drone is just capable of faster descent than my other drones so entered VRS pretty easily. NOW I know what was happening and what to do about it. Thank you so much for the lesson!!!
Many many thanks for this (and all your other vids). I have an X5C and now have bought an X8C. Seeing your excellent tutorial videos is going to help me avoid these problems. Crashing an X8C would be a much bigger deal than crashing the heavier X8C. Cheers!
Very helpful for us new fliers, I follow 2 channels about drones as I'm looking to upgrade from my great but toy drone (only available here in Australia) The reason i've chosen yourself and RC Sailors is you help us newbies, you tell it as it is, and give us the viewers an honest appraisal of the quads available. Thanks very much!
I am also a commercial helicopter pilot of 30+ years and I agree with justinspirational, you explained it so I don't have to :-) My 2 bits... you need 3 things to get into "Settling With Power" (we don't like using vortex ring to describe it as it is slightly different). Settling with power must have these 3 things to occur: 1. POWER/THRUST/HOLDING LOTS OF POWER (typical condition = TOO HEAVY) (like the power required to hover or more). 2. ROD - Rate Of Descent (you must be descending, even if only slightly it can occur). 3. LOW OR NO AIRSPEED - Settling with power will only happen if you are hovering or have very low airspeed. Basically you are falling into your own down-wash and the Helicopter, now moving in descending air does not know the air is descending and will rumble and shake and then all your controls become mushy and you will start falling with one option left to save your butt. You must gain some fwd speed and as you have demonstrated (very well) some fwd speed fixes the problem very quickly. It also pays to reduce power as you nose fwd. The reason full size helis crash from this condition is often because there is no room for you to descend rapidly, fly fwd and escape the condition without hitting the ground if too low or obstacles if in a tight spot. Just think of your down-wash and avoid it if descending and you will be ok. On a full size heli it can also happen in your Tail Rotor, if you do a fast pedal turn in the hover you can experience it in a horizontal way, your tail rotor will become ineffective and you can loose control as the torque takes over and the spinning begins. Not that common but something that can happen. I also think a very fast quick stop in a flare could put you into it if you end up with the 3 things mentioned, it is possible as you would be descending into your down-wash with power on and the rate of descent is your flare with low or no airspeed. I have been wondering about this for a while, thanks for the demo, I am a new Quadcopter Flyer too and I am amazed by the power of the Quad, it is incredible. It is very tempting once you do a pop and roll to just descend back down to where you are, this is where people will get into trouble, I have been avoiding doing that for the very reason you have explained. Great video, also really cool to see Drone Flyers are taking the time to understand the Theory of Flight, it is not essential but sure does help if you understand it, it is also really interesting. Good points on Ground Effect and Translational Lift too :-) These are all things we think about every time we fly. I have been thinking that a vertical tail fin could be fun to try, it would help keep the Quad pointing fwd once it gained speed, could be good for LOS flying anyway as I am having a crappy time learning LOS flying, orientation is a nightmare, just looks like a dot to me and I have pretty good earsight!! I am about to transition from LOS to FPV but want to get my Acro skills sorted first. Thanks again, very well done, something all Drone flyers should watch!
This is so informative TYVM for explaining this. I'm an old man but new to this hobby and every day I learn something not only new to me but crucial to be known. All of your vids are well done and I have learned so much from them. I picked up a small syma X12 about a week ago and it is a blast to fly and learn with (before I saw the vids of what a nice newbie quad the X11 is) . After watching a lot of your vids I was gonna pick up the X5C-1 to continue my training and enjoyment but I caught a Holy Stone M68R+ on special yesterday and went with it for now. Hope it is as stable as the X5C-1 but if not no biggie, it will just be another lesson learned.
Many thanks for this tutorial. I have been flying for 4 years and did not know of VRS until I read the latest CASA (Australian aviation safety) manual of standards for RPAS/UAV.
As always, really enjoy these vids of yours, this has been extremely educational for me. I have had these states before, but never knew the science behind it, which really explains why I ran across it.
Thankyou for explaining VRS to me. I had noticed the phenomenon with my X5C after trying some freefalls and thought the batteries were just getting low. Now I understand it better :)
Excelente aporte, creo importante mencionar, que el cuadricoptero utiliza el gps para determinar la posición y barómetro para determinar la altura; cuando entramos en una condición de descontrol como el caso del Vortex Ring State, el drone pierde altura de manera súbita y acelerada; en nuestro intento de recuperarlo, damos stiks laterales o adelante/atrás para salir del anillo de la muerte, sin embargo, el dron no responde adecuadamente por falta de sustentación. Lo que no podemos preveer, es que el Drone, por sí mismo intenta recuperar su posición inicial (altura y coordenadas previas al VRS) a lo que se suma la orden que hemos emitido con la emisora (movimientos de traslación), siendo impredecible el rumbo que tomará el ave una vez recupere sustentación, por lo cual, al salir del Vorex Ring State es probable que el drone tome un rumbo inesperado y termina estrellado contra cualquier estructura que se encuentre cerca!!! En ocasiones, el drone se precipita a tierra por el VRS y por el “efecto suelo” rebota contra el suelo y se eleva de manera acelerada para intentar recuperar las coordenadas y altura inicial y termina enredado en cuerdas de luz, etc. Para evitar los accidentes debemos practicar mucho en áreas abiertas y por supuesto, lejos de personas y propiedades que pudieran resultar afectadas!!!
Excellent video! My cheerson cx20 has crashed twice because of vortex ring state. This video will help me alot. I thought my quad was defective but now i know it was user error. Awesome video!!!!!!
I came across this sorta by accident when I first started flying my quadcopter. I learned very quickly to get out of VRS by simple slamming the quad into a diagonal direction and dropping about a foot, then throwing on some power as I keep it going sideways. It comes out of it every time now. I've actually practiced this like you did in the video. Now I just have to learn how to fly in circles in the forward direction, I go side to side, leaving the quad pointed straight ahead. I am easy disoriented and have to practice this with the help of your videos. I think I have to get around the red being the front. When driving a car, I know a cars backside by it's red lights.
Thank you so much! I was flying low to the ground and had this issue and it scared me! I thought I had damaged the gyros but it was flying perfectly the day before. This describes my issue perfectly!
Great video. Your point about 'copters with a return to home feature having unusually slow descent rates is very pertinent. By the time this feature needs to be activated it is likely that the batteries are already dangerously low and I have seen several videos of aircraft falling out of the sky when the batteries go flat under return to home mode.
Aaah thank you Q101, I crashed my Hubsan X4 Pro just yesterday, descending straight down from height I let the throttle right of and it started to wobble and twist and just fell to the ground, luckily onto a patch of boggy ground :-). Ive been trawing the net ever since thinking I had a faulty product so thank you once again for putting my mind at rest, you get a big thumbs up from me. ;-)
Hi, I'm just learning to fly quad-copters and I've found your videos and website really helpful and informative. I'm using a Hubsan X4 and working on turning circles at the moment between rain showers. I wondered why when I get disoriented and drop it that it comes straight down so fast but this video has just explained vortex ring state and what's happening so now I understand it much better. Thanks for all the information and great videos.
I recently got an X380 and in my several flights I fortunately haven't encountered this problem. Then again, I wasn't even aware of it!! Now that I know, I can consciously work to avoid it. Thanks!!!
Thank you for this video! I kept hearing you talk about VRS, but didn't know what it was. I finally did a search and this video popped up. This is exactly what happened to my CX-20 a few weeks ago. I couldn't figure out what went wrong and so I haven't flown it since. (I was afraid of damaging people, property, and my $300 investment!) Thank you again for the great explanation and demonstration. My background is fixed wing aircraft. It might be helpful to put a link to this video in your other videos when you mention VRS. Thanks for your awesome reviews as well!!
Fantastic explanation, just yesterday we landed with 1% Battery, in RTL mode, and just didn't understand why so slow descent, well thanks to you now we know.
Thank you Mr 101, Your VRS lesson was great! now I understand why this happened to me with my Huanqi H899, I just thought It didnt like a fast descent! :-) Just started flying quadcopters and absolutely loving them.
Thanks for posting this video, I recently bought a DJI Inspire, and have had multiple UAV's over the past few years, starting with the Phantom 1, and building my own F550 Hex. I've flown them many, many, MANY times, and never new about the Vortex ring, how to come out of one, or how to avoid them all together. I am always easy on the sticks, even when landing, so that's probably why I've never experienced it, but none the less, good tips, and I will start to use the decent options that you show in this video. Thanks again, you may have just saved me a model. =)
Could've sworn there was something wrong with my design, every time I begin a fast descent it would wobble and I'd panick. Glad I found this video, thanks!
I really enjoy your videos. There are a lot of guys giving reviews (and I do like your reviews) but you are one of the only guys i have found that gives good, easy to understand, lessons on flying. As a newbie... I appreciate it :)
This is incredibly helpful. I literally had no idea why it happened to me, thought my motors were too weak for the camera setup. I was lucky though, because it just bounced and kept going. :) Thank you very much for your awesome vids!
Thank's a lot for that tutorial video. I've just bought a Syma X8c and had a lot of trouble with that VRS. So I'm not a physisian and had no clue about the VRS, had never ever heard about it. . I own a dm007 since last year and never had problems with the wobble of death. Now with my "bigbird" I felt like an absolute noob. Now I know why. Thank you and keep on testing. P.S. I wish would have an area like you to test fly my copters. No trees for kilometers.... PARADISE!!! ;)
I have been flying for a little while yet still working on some flying skills. I have seen this yet I did not know what it was, Thank You for explaining this. I have already started not coming straight down.
Through my testing with a quad, I think generally as long as you keep the overall quad weight at 40-45% total thrust and under, it is easy to recover from VRS. Also, higher pitch props may give slightly less thrust at hover, but work well in turbulent air. (tested with 1650 and 1655 props). Finally, make sure the PID values are tuned very well, especially for custom builds.
Great info. Just got my X5C-1 today! First flight in the books. It's raining so it was mostly learning to hover (under the deck awning! LOL)! Learned a lot from your video! Thanks
Nice tutorial. Many of those principals I learned in flight training small fixed wing aircraft. Those principals are really apparent when you get to my Cheerson CX 20 class of quad. Moves lots of air and can get quite unstable below 5 ft height.
This is a very useful. explanation that every pilot should watch. A good reminder and might even save some lives for the real pilots out there. Thanks Q101!
Realy helpfull for me. I have just build my own F450 quad and this is exactly what happend to me from 15m altitude. I thought it was somthing wrong with my setting on the GPS, Compass or gyro etc. Thx alot for explayning this to me. I will be much more carfull decending from now on espessialy when i have my GoPro under neath it.
Thank you for your videos, I like them a lot and learn flying tips as well. You are passionate about quadcopters and it shows. Once again, thank you and keep flying!
Well now that I've reduced my wingtip vortices I'd like to say, I had no idea what was going on with my quads when they did this. I just thought some quads had a better recovery rate than others when you let off the throttle. It seems power to weight ratio has a fair amount to do with VRS as well, my Latrax Alias seemed to recover faster. In watching some of my personal videos it was the forward pitch and rudder that helped me out in this situation which I just did naturally, dunno why? I never had one hit the ground but now I can avoid it all together in the future, thanks once again.
Thanks for posting this and good video. I see this when flying outdoors with some of my smaller micro quads. It does a very similar 'death wobble' descent, I apply full power and it barely responds, if at all. Will try full forward throttle next time and see if I can get out of it that way. I've also had it happen when I flew directly under another quad.
Thank you! I just read about this in Wikipedia, and how to recover (related to single or dual full size helis). I've done so often a full rate descents on my Phantom 1, and the wobbling is there. The rate of descent is said to be limited by the firmware to not get into serious vortex ring state. And it seems true, it's always been in control (excluding the wobble, which is not that bad either). I've hit the ground though, bouncing back into air but I've just thought I didn't have enough clearance. Knowing this would lift my hair if the descent wasn't limited!
ahh!!! I was experiencing this with my hubsan x4 and actually it led me down the trail of "needing a more powerful/better quadcopter". Don't regret my purchase at all (picked up an x5sc explorer 2 and an X8C) but good to know its down to technique and not that my hubsan is underpowered! :)
This happened to me earlier today on my ZMR250. The first time, I lost altitude and had a hard landing. The second time, I pitched forward and increased throttle and the VRS wobble quickly went away...whew! Will be researching into whether or not I can edit my P value in my PID's to decrease the chance of this happening.
excellent explanation and demonstration, I had this happen to me with a camera and new blades and thought it was caused by the new blades, now I know what is was...... Great video, thanks
When taking off real slow with quads but especially with heavy larger helicopters the copter want to tilt to the side. After watching this video I looked this stuff up and it said when departing the ground effect state VRS can occur. .According to the article I'm reading this is what happened to the Heli that crashed during the bin laden raid. Very happy I follow your channel.
That was simply brilliant! I really learned something watching that video, so thanks so much for such a clear and concise demonstration and explanation.
Thankyou! I was really curious why my new quadcopter was doing this and I thought there was something wrong!! Now I know how to get out of it, Thankyou so much :)
Love your work Quadcopter 101, great tip. I also noticed this when I was learning to fly quads but I never knew why it stops the wobbling till now. Thanks for explaining the vortex lift.
Thanks for the info on VRS. I kept having it with my syma x11c and thought it was a fault or lack of power so I kept jamming on the throttle full, making it worse!
Yep, VRS is a big problem as weight is added to a quadcopter. Just did the following video of a newly released micro quadcopter with HD camera yesterday. The first crash was VRS due to the weight of the camera. Even knowing that it was VRS and what to do, I still couldn't slide out of it before meeting the ground. th-cam.com/video/rjYIE63ZZ94/w-d-xo.html
Another tip to get out of VRS. If there is a breeze and you are descending, always pitch AGAINST the wind direction instead of with it. So forward pitch may not be the answer if you are facing forward with the breeze. If you are moving WITH the breeze and descending, the wind speed can negate your actual speed and the quad will act as if it is descending vertically with no breeze and enter VRS. Does that make any sense? Don't know if I explained it well. Anyway, good video about the VRS effect! Happy flying!
You are absolutely correct. Fixed wing models need to start into the direction the wind comes from. It is very easy to understand, that higher pressure in the direction you are flying results in higher pressure underneath the propellers.
This effect crashed my phantom 2 twice (the first time in a river :/ ). I thought that was a defect of the quad, I was going to sell it or something. THANK YOU !
It depends on how weighted down the quadcopter is. You see it much more frequently and severely with camera quads. Unfortunately, this is especially true for the high cost ones loaded down with GoPros and gimbals Look in the right column of recommended videos to see what I mean..
Great video. I wish I could see the radiocontroll though in the same time. But its really great. It sounds so Easy. But The only time I been into this so called vortex is when I've done a flip. :-) SO that means if I do a flip I kinda have to make it move in the same direction as the flip to prevent it from a vortex is that corrext understod. So a forward flip must still be forward.
Good video. Now, i have the Syma X5C-1 model and when it gets high (about 100meters) i take it down by closing the throttle completely and opening it again about 10 meters of the ground. Never had that VRS problem. But, i noticed it 2-3 times when doing flips at very low altitude just 3 meters above the ground. Maybe some quads are more sensitive to that than others.
The video is great and gives great tips to operators, but seems to have two misunderstandings. First is translational lift, which occurs from the aircraft moving forward. It works due to the rotor being tilted toward the air it's moving forward into. Air has mass and you're increasing the mass flow through your rotor. You're also reducing the effect of wing tip vortices by moving away from them and having the air you're moving into blow into them reducing their effect. All lift is created by newton's second law, to move a mass up you have to push a mass down. The more mass you can push down and have most it go directly in the direction pushing means you can create more lift. The second thing is the description of a vortex ring state. A vortex ring state occurs from the upward moving air near the rotor hub during hover or decent, and the increasing size through momentum of air created by the wing tip vortices. The vortices get larger without lateral movement and capture and inflate the upward movement of air near the hub during descent. The reason air can move upwards near the hub is due to the slower speed of the blade as you move closer to the hub and is caused by the aircraft's descent or by vortices increasing in size until the upward moving air from them can overcome the slower moving air near the hub. To visualize a vortex ring of air think or the vortices creating a donut of air near the wingtip. That donut can grow during hover. Now hopefully you can also see why lateral movement gets you out of it
Really noticeable with the Hubsan X4C - I always reckoned this was because of the small blade size compared to the weight of the quad. Now I have a name to put to the effect :)
About translational lift, I always have to throttle up to maintain altitude with a steeper angle of attack, which makes sense to me because the air isn't being pushed straight down anymore. Does translational lift only apply with subtle drifting?
Thank you very much. i am new to the quad-copter scene and thought i was doing something wrong but didn't know what lol. Now i know thanks to your vid. I have put some vids on myself from my flights and without sounding cheesy , i have used your vids to learn a lot of flight craft. Also i am waiting for my new v666 to be delivered and it was your test that made me pick that one from all the rest in the price range . Many thanks and keep going. ;-)
Yep - Experienced VRS with my new X8C today.. Twice! I got out of it the second time - Remembered to go into horisontal flight and get into clean air! Scary how quickly these things come out of the sky!
I work in the field of rotary-wing aerodynamics and this video is an excellent example of how such low disk-loading (vehicle weight divided by disk area of all rotors) rotorcraft can get into VRS at much lower rates of descent than piloted aircraft. Thanks for posting!
Thanks so much for this valuable VRS tip Q101! This just happened to me with my new XK X252 a couple of days ago. I'm still a novice, not to flying RC or real planes, but RC drones. I was out flying the X252 when I realized it was getting a bit high. I immediately pulled the power back some and it went into a vertical descent. Almost immediately it began wobbling badly on the way down. I added power and luckily I still had plenty of altitude so it smoothed out and I was able to fly it out of the descent and the story had a happy ending. In fact, I thought it was just the X252 not being very stable since it is a little squirrelly being a high performance brushless 3D quad. Now I know I was at fault and will avoid vertical descents in the future.
Thanks again! I wish I had run across this tip earlier.
I wish more videos for drone beginners would mention this, because it seems like a common problem, something you need to watch out for on _every_ descent.
Most modern drones have sufficient power to weight (greater than 2:1) to power out of VRS
Thank you Quad 101. I've been into RC for years different types and just got addicted to quad platform. It has been AMAZING! Today during a flight my CX-20 went into VRS and fell like a stone, but was able to catch in ground effect and do almost no damage. This video will inspire me to train for VRS issues in the future. Could have been a very costly day for copter,gopro, and fpv transmitter. Keep the education coming our way. Shon
Just lost my first quadcopter due to this!!! Now I know..... great videos and info I'm learning a lot thank you for posting!
Your tutorials have been spot on! Being an advanced beginner, my two "big birds" are the Syma X8C and the Wiltoy 686. Applying what I've learned from you, it's made quad flying a much more enjoyable experience. Thank you!
Thank you so much for this info! This should be required reading with all quads! My DJI entered VRS at 60 feet yesterday luckily over a soft field. This is a very dangerous state to enter into and too many pilots are not made aware of this issue and they fly over people before knowing that this is an issue. Thank you much my friend, you got my subscription!
Excellent again. I sure have learned something. THANKYOU once again for a great explanation of Vortex ring state. Now I know why my quad woobles on descent. Just need to apply some forward pitch during a rapid descent.
Sandy
I'm a full scale helicopter pilot- vortex ring state (vrs) will only occur descending vertically in calm/no winds but also moving forward slowly and descending rapidly/steeply with a tail wind (tailwind blows vortices into the path of the props)- if you are descending vertically rapidly with a stiff wind- the vortices are likley to be blown out of the descent path and less likely to create vrs- if you get into vrs- don't add more throttle (it will exacerbate vrs)- instead gain airpseed (forward, but altenately backwards or laterally- best move upwind) to get out of the vortices and if altitude permits lower throttle to reduce vortices- vrs in helicopters is very dangerous and must be avoided at all costs- for helicopters like the robinson R22- 3 things need to happening at the same time for vrs to occur- at least 10-20% power applied, airspeed (not groundspeed) less than effective translational lift ETL (less than around 15-24 knots) - note- you can have airpseed just hovering on a spot in winds greater than ETL speeds and third a descent rate of greater than 300 feet/minute- don't know how that translates to multirotors/rc helicopters in general- but food for thought..basically avoid vrs by descending slowly (slower vertical speed, descending into wind (not a tail wind),if possible with some forward airspeed and not too steep an approach- IGE for quads is probably less than a foot aboveteh ground- anything above a foot above the ground is going to be an OGE hover rwequiring more power- and hard to maintain on hotter, humid days - especially at higher elevations, where the air is thinner
that’s an outdated recovery concept that you mention. Look into the vuichard recovery technique (which wont work for quads as you need an anti torque rotor for it)
Bla bla bla bla...if I had a rope I would hang myself
Well put;
For multi-rotor, you don't have a swashplate / collective, I believe your best bet is to full throttle and full pitch together because you need the throttle to cause the pitch to heppen and it also could significantly change the angle of attack of blades relative to the vortices which I assume disrupts them. Full pitch forward would cause the multi-rotor to essentially fall forward translationally, across and downward, but with all your energy stored in the blades for lift once you exit the vortex which given sufficient altitude and thrust to weight ratio should recover itself in the manner this video demonstrates. Agree with pushing it upwind, will definitely recover better, but if there isn't much wind or you don't have time to think I would say just push forward immediately, most multi-rotors are low altitude when this happens, probably coming in for a landing and the time to react is very low.
If you throttle down on a multi-rotor you decrease your RPM not your blade pitch, it is going to fall like a rock with no energy stored in your blades and a diminished ability to gain forward airspeed. In a helicopter you still have full RPM you have only reduced your blad pitch and then to move translationially out of it your cyclic will increase the blade pitch only where you need it (a pitch increase 90 degrees in advance to the opposite side of your intended direction), and at full RPM.
Collective down and cyclic pitched on a helicopter's rotor will give you un-even lift on your disk which I wonder and this is just an assumption; if that could help to disrupt some of the vortex as well even before you move fully out of it. Makes sense for a helicopter to do it that way, but not a multi-rotor.
My own experience with it; got caught out once, all of the other times I was able to recover from it just fine. I avoid vertical descents and fly like this video recommends most of the time.
Interestingly I have built some coaxial multi-rotors X8 configuration and found that you can drop them really hard and they will self recover from the wobble with throttle alone, with propellers spinning in opposite directions, they don't seem to sustain a vortex for long. Particularly if you make the bottom prob spin at a higher RPM to the top one in programming.
Large diameter props on low KV motors are very prone to VRS and should be landed like a fixed wing with some pitch or descended vertically at a very slow rate.
Most that I have flown with a high power to weight ratio and decent quality motors / props etc can recover pretty quickly, an FPV drone or Mavic or something barely requires any thought given to this at all.. But if flying a large heavy lift drone with a decent payload or a cheap, underpowered one like in this video, be careful of VRS, you may not be able to power out of it in time.
Noticed some weird wobble when descending Q500+ today (maiden flight) so I stopped home mode and manually landed the quad slowly. I thought it's because of the wind but gut feeling tells me it's more than that. I then did some research and found out the "wobble of death" aka Vortex Ring State. Ended up with your video and I'd say it's the most helpful so far. Thank you so much!
Excellent demonstration !!! I was familiar with these effects in theory but have never seen them demonstrated so clearly. You have turned theory into reality and made it much more memorable.
I watched this video some time ago. Today it saved my Scout X4 with a camera and gimbal. I was at about 50 meters when it started to plummet. Though I was not descending it was turbulent and a gust may have initiated descent from hover into VRS. I recognized it and gave full forward thrust. After about 25 meter she recovered. I just wanted to say a huge THANKS!
Thanks so much for this video!
I was flying in Slovakia last year and whilst bring it down from a high altitude it went absolutely mental for no reason (full throttle did nothing) and dropped rapidly for about 60 metres rocking violently before it settled a few metres above a tall tree (phew).
I’d since been blaming the quad for the situation, but I now know it was a classic case of VRS caused by descending into powerful thermals (it had been a very hot day).
I was lucky as I now believe the tree had dampened the turbulent air and saved my quad form smashing into the ground.
After watching your great tutorial I’m now aware of the causes or VRS, how to avoid VRS and hopefully escape a future VRS situation.
Many thanks again :-)
We had this happen on a Phantom 2 Vision Plus and the resulting hard landing busted the camera assembly and some other bits are looking rather sad and sorry. The model shop we bought it from told us about VRS and this is the best video I've found so far explaining the situation and teaching how to cope with it. It scared the hell out of us, so it's nice to know it's a somewhat common phenomenon.
That's so funny. I'm a total beginner, and just this evening I was flying my new Hubsan H502E. There were a couple of times I had to make a quick descent and it went to the ground in VRS just like you said in this video...except I had never heard of VRS and wondered what was wrong with the drone. Turns out this particular drone is just capable of faster descent than my other drones so entered VRS pretty easily. NOW I know what was happening and what to do about it. Thank you so much for the lesson!!!
Many many thanks for this (and all your other vids). I have an X5C and now have bought an X8C. Seeing your excellent tutorial videos is going to help me avoid these problems. Crashing an X8C would be a much bigger deal than crashing the heavier X8C. Cheers!
Very helpful for us new fliers, I follow 2 channels about drones as I'm looking to upgrade from my great but toy drone (only available here in Australia) The reason i've chosen yourself and RC Sailors is you help us newbies, you tell it as it is, and give us the viewers an honest appraisal of the quads available. Thanks very much!
I am also a commercial helicopter pilot of 30+ years and I agree with justinspirational, you explained it so I don't have to :-) My 2 bits... you need 3 things to get into "Settling With Power" (we don't like using vortex ring to describe it as it is slightly different). Settling with power must have these 3 things to occur: 1. POWER/THRUST/HOLDING LOTS OF POWER (typical condition = TOO HEAVY) (like the power required to hover or more). 2. ROD - Rate Of Descent (you must be descending, even if only slightly it can occur). 3. LOW OR NO AIRSPEED - Settling with power will only happen if you are hovering or have very low airspeed. Basically you are falling into your own down-wash and the Helicopter, now moving in descending air does not know the air is descending and will rumble and shake and then all your controls become mushy and you will start falling with one option left to save your butt. You must gain some fwd speed and as you have demonstrated (very well) some fwd speed fixes the problem very quickly. It also pays to reduce power as you nose fwd. The reason full size helis crash from this condition is often because there is no room for you to descend rapidly, fly fwd and escape the condition without hitting the ground if too low or obstacles if in a tight spot. Just think of your down-wash and avoid it if descending and you will be ok. On a full size heli it can also happen in your Tail Rotor, if you do a fast pedal turn in the hover you can experience it in a horizontal way, your tail rotor will become ineffective and you can loose control as the torque takes over and the spinning begins. Not that common but something that can happen. I also think a very fast quick stop in a flare could put you into it if you end up with the 3 things mentioned, it is possible as you would be descending into your down-wash with power on and the rate of descent is your flare with low or no airspeed.
I have been wondering about this for a while, thanks for the demo, I am a new Quadcopter Flyer too and I am amazed by the power of the Quad, it is incredible. It is very tempting once you do a pop and roll to just descend back down to where you are, this is where people will get into trouble, I have been avoiding doing that for the very reason you have explained.
Great video, also really cool to see Drone Flyers are taking the time to understand the Theory of Flight, it is not essential but sure does help if you understand it, it is also really interesting. Good points on Ground Effect and Translational Lift too :-) These are all things we think about every time we fly.
I have been thinking that a vertical tail fin could be fun to try, it would help keep the Quad pointing fwd once it gained speed, could be good for LOS flying anyway as I am having a crappy time learning LOS flying, orientation is a nightmare, just looks like a dot to me and I have pretty good earsight!! I am about to transition from LOS to FPV but want to get my Acro skills sorted first.
Thanks again, very well done, something all Drone flyers should watch!
This is so informative TYVM for explaining this. I'm an old man but new to this hobby and every day I learn something not only new to me but crucial to be known. All of your vids are well done and I have learned so much from them. I picked up a small syma X12 about a week ago and it is a blast to fly and learn with (before I saw the vids of what a nice newbie quad the X11 is) . After watching a lot of your vids I was gonna pick up the X5C-1 to continue my training and enjoyment but I caught a Holy Stone M68R+ on special yesterday and went with it for now. Hope it is as stable as the X5C-1 but if not no biggie, it will just be another lesson learned.
Many thanks for this tutorial. I have been flying for 4 years and did not know of VRS until I read the latest CASA (Australian aviation safety) manual of standards for RPAS/UAV.
Your videos are great for beginner quad flyers like me. Thanks.
I've only been learning to fly about 2 months or so, so glad to have found such a great teacher!!!!!!!!!! Thanks Man!!!!!!
Belated congrats on being a reference in wikipedia on VRS!
Well would you look at that! en.wikipedia.org/wiki/Vortex_ring_state
As always, really enjoy these vids of yours, this has been extremely educational for me. I have had these states before, but never knew the science behind it, which really explains why I ran across it.
This is the answer to what I experienced last night. I wondered if there was something wrong with the copter. Now I know. Thanks.
Thankyou for explaining VRS to me. I had noticed the phenomenon with my X5C after trying some freefalls and thought the batteries were just getting low. Now I understand it better :)
Excelente aporte, creo importante mencionar, que el cuadricoptero utiliza el gps para determinar la posición y barómetro para determinar la altura; cuando entramos en una condición de descontrol como el caso del Vortex Ring State, el drone pierde altura de manera súbita y acelerada; en nuestro intento de recuperarlo, damos stiks laterales o adelante/atrás para salir del anillo de la muerte, sin embargo, el dron no responde adecuadamente por falta de sustentación. Lo que no podemos preveer, es que el Drone, por sí mismo intenta recuperar su posición inicial (altura y coordenadas previas al VRS) a lo que se suma la orden que hemos emitido con la emisora (movimientos de traslación), siendo impredecible el rumbo que tomará el ave una vez recupere sustentación, por lo cual, al salir del Vorex Ring State es probable que el drone tome un rumbo inesperado y termina estrellado contra cualquier estructura que se encuentre cerca!!!
En ocasiones, el drone se precipita a tierra por el VRS y por el “efecto suelo” rebota contra el suelo y se eleva de manera acelerada para intentar recuperar las coordenadas y altura inicial y termina enredado en cuerdas de luz, etc.
Para evitar los accidentes debemos practicar mucho en áreas abiertas y por supuesto, lejos de personas y propiedades que pudieran resultar afectadas!!!
Excellent video! My cheerson cx20 has crashed twice because of vortex ring state. This video will help me alot. I thought my quad was defective but now i know it was user error. Awesome video!!!!!!
I came across this sorta by accident when I first started flying my quadcopter. I learned very quickly to get out of VRS by simple slamming the quad into a diagonal direction and dropping about a foot, then throwing on some power as I keep it going sideways. It comes out of it every time now. I've actually practiced this like you did in the video.
Now I just have to learn how to fly in circles in the forward direction, I go side to side, leaving the quad pointed straight ahead. I am easy disoriented and have to practice this with the help of your videos. I think I have to get around the red being the front. When driving a car, I know a cars backside by it's red lights.
This may be my problem I mentioned in one of your other videos. I will have to try this recovery plan. Really enjoy your videos. Keep them coming!
Thank you so much! I was flying low to the ground and had this issue and it scared me! I thought I had damaged the gyros but it was flying perfectly the day before. This describes my issue perfectly!
That is an awesome technic for escaping VRS! I have a V222 and I thought that there may have been a transmission problem losing the signal. Great!
101, just learned about VRS yesterday, still learning. Thanks for posting and demonstrating VRS and how to escape it. Great Video!
Great video. Your point about 'copters with a return to home feature having unusually slow descent rates is very pertinent. By the time this feature needs to be activated it is likely that the batteries are already dangerously low and I have seen several videos of aircraft falling out of the sky when the batteries go flat under return to home mode.
Aaah thank you Q101, I crashed my Hubsan X4 Pro just yesterday, descending straight down from height I let the throttle right of and it started to wobble and twist and just fell to the ground, luckily onto a patch of boggy ground :-).
Ive been trawing the net ever since thinking I had a faulty product so thank you once again for putting my mind at rest, you get a big thumbs up from me. ;-)
Hi, I'm just learning to fly quad-copters and I've found your videos and website really helpful and informative. I'm using a Hubsan X4 and working on turning circles at the moment between rain showers. I wondered why when I get disoriented and drop it that it comes straight down so fast but this video has just explained vortex ring state and what's happening so now I understand it much better. Thanks for all the information and great videos.
I recently got an X380 and in my several flights I fortunately haven't encountered this problem. Then again, I wasn't even aware of it!! Now that I know, I can consciously work to avoid it.
Thanks!!!
Thank you for this video! I kept hearing you talk about VRS, but didn't know what it was. I finally did a search and this video popped up. This is exactly what happened to my CX-20 a few weeks ago. I couldn't figure out what went wrong and so I haven't flown it since. (I was afraid of damaging people, property, and my $300 investment!) Thank you again for the great explanation and demonstration. My background is fixed wing aircraft. It might be helpful to put a link to this video in your other videos when you mention VRS. Thanks for your awesome reviews as well!!
Fantastic explanation, just yesterday we landed with 1% Battery, in RTL mode, and just didn't understand why so slow descent, well thanks to you now we know.
Thanks Buddy, ive just ordered a Syma X5C "my first Quadcopter" so these tips will no doubt help me!
the VRS phenomena explains so much about my quads behavior (DJI FC40) when i've flown it sometimes.. thanks for this video! :)
Thank you Mr 101,
Your VRS lesson was great! now I understand why this happened to me with my Huanqi H899, I just thought It didnt like a fast descent! :-)
Just started flying quadcopters and absolutely loving them.
Thanks for posting this video, I recently bought a DJI Inspire, and have had multiple UAV's over the past few years, starting with the Phantom 1, and building my own F550 Hex. I've flown them many, many, MANY times, and never new about the Vortex ring, how to come out of one, or how to avoid them all together. I am always easy on the sticks, even when landing, so that's probably why I've never experienced it, but none the less, good tips, and I will start to use the decent options that you show in this video. Thanks again, you may have just saved me a model. =)
Could've sworn there was something wrong with my design, every time I begin a fast descent it would wobble and I'd panick. Glad I found this video, thanks!
I really enjoy your videos. There are a lot of guys giving reviews (and I do like your reviews) but you are one of the only guys i have found that gives good, easy to understand, lessons on flying. As a newbie... I appreciate it :)
+Tukarama Make sure to also check out my flight school blog (best viewed on computer) quadcopter101.blogspot.com/
This is incredibly helpful. I literally had no idea why it happened to me, thought my motors were too weak for the camera setup. I was lucky though, because it just bounced and kept going. :) Thank you very much for your awesome vids!
This was a very helpful video! My last time out with my V222 I was able to come out of the VRS stage and make great landing. Thanks again!
Thank's a lot for that tutorial video. I've just bought a Syma X8c and had a lot of trouble with that VRS. So I'm not a physisian and had no clue about the VRS, had never ever heard about it. . I own a dm007 since last year and never had problems with the wobble of death. Now with my "bigbird" I felt like an absolute noob. Now I know why. Thank you and keep on testing. P.S. I wish would have an area like you to test fly my copters. No trees for kilometers.... PARADISE!!! ;)
Great stuff! Very interesting about how turbulent air reeks havoc on a too rapid, straight down descent.Cheers!
I have been flying for a little while yet still working on some flying skills. I have seen this yet I did not know what it was, Thank You for explaining this. I have already started not coming straight down.
Through my testing with a quad, I think generally as long as you keep the overall quad weight at 40-45% total thrust and under, it is easy to recover from VRS. Also, higher pitch props may give slightly less thrust at hover, but work well in turbulent air. (tested with 1650 and 1655 props). Finally, make sure the PID values are tuned very well, especially for custom builds.
Great info. Just got my X5C-1 today! First flight in the books. It's raining so it was mostly learning to hover (under the deck awning! LOL)! Learned a lot from your video! Thanks
Nice tutorial. Many of those principals I learned in flight training small fixed wing aircraft. Those principals are really apparent when you get to my Cheerson CX 20 class of quad. Moves lots of air and can get quite unstable below 5 ft height.
Best quadcopter channel on youtube. Thanks for all the great and helpful videos! Can you please explain when and how a person would use trim of power.
This is a very useful. explanation that every pilot should watch. A good reminder and might even save some lives for the real pilots out there. Thanks Q101!
Realy helpfull for me.
I have just build my own F450 quad and this is exactly what happend to me from 15m altitude. I thought it was somthing wrong with my setting on the GPS, Compass or gyro etc. Thx alot for explayning this to me. I will be much more carfull decending from now on espessialy when i have my GoPro under neath it.
Just got my first drone... learning so much from your channel. Thanks!
Excellent explanation and nice demonstration of Vortex Ring State.
i stumbled on this cure .sheer chance with x5c. only been flying 2 weeks.
great tutorials--thanks
Thank you for your videos, I like them a lot and learn flying tips as well. You are passionate about quadcopters and it shows. Once again, thank you and keep flying!
Well now that I've reduced my wingtip vortices I'd like to say, I had no idea what was going on with my quads when they did this. I just thought some quads had a better recovery rate than others when you let off the throttle. It seems power to weight ratio has a fair amount to do with VRS as well, my Latrax Alias seemed to recover faster. In watching some of my personal videos it was the forward pitch and rudder that helped me out in this situation which I just did naturally, dunno why? I never had one hit the ground but now I can avoid it all together in the future, thanks once again.
Thanks for posting this and good video. I see this when flying outdoors with some of my smaller micro quads. It does a very similar 'death wobble' descent, I apply full power and it barely responds, if at all. Will try full forward throttle next time and see if I can get out of it that way. I've also had it happen when I flew directly under another quad.
Thank you! I just read about this in Wikipedia, and how to recover (related to single or dual full size helis). I've done so often a full rate descents on my Phantom 1, and the wobbling is there. The rate of descent is said to be limited by the firmware to not get into serious vortex ring state. And it seems true, it's always been in control (excluding the wobble, which is not that bad either). I've hit the ground though, bouncing back into air but I've just thought I didn't have enough clearance. Knowing this would lift my hair if the descent wasn't limited!
ahh!!! I was experiencing this with my hubsan x4 and actually it led me down the trail of "needing a more powerful/better quadcopter".
Don't regret my purchase at all (picked up an x5sc explorer 2 and an X8C) but good to know its down to technique and not that my hubsan is underpowered! :)
This explanation was actually very helpful for VRS, thanks
This happened to me earlier today on my ZMR250. The first time, I lost altitude and had a hard landing. The second time, I pitched forward and increased throttle and the VRS wobble quickly went away...whew! Will be researching into whether or not I can edit my P value in my PID's to decrease the chance of this happening.
excellent explanation and demonstration, I had this happen to me with a camera and new blades and thought it was caused by the new blades, now I know what is was......
Great video, thanks
When taking off real slow with quads but especially with heavy larger helicopters the copter want to tilt to the side. After watching this video I looked this stuff up and it said when departing the ground effect state VRS can occur. .According to the article I'm reading this is what happened to the Heli that crashed during the bin laden raid. Very happy I follow your channel.
Good informative video. Applying a slight yaw to the pitch helps gett of the VRS faster .
Dude I totally thought my drones' motors were just going bad. I had no idea this was even a thing. Thanks for the info!
I've heard this referred to as The Wobble Of Death.
Excellent breakdown, thanks for the analysis.
Thanks! Have added that to the tags and info above. Maybe that will help other people find this video. Thanks again.
That was simply brilliant! I really learned something watching that video, so thanks so much for such a clear and concise demonstration and explanation.
One of the best guides I've seen yet O_O
Thanks, now I understand why the v686k dropped down pretty often even on full throttle after lowering altitude.
Thankyou! I was really curious why my new quadcopter was doing this and I thought there was something wrong!! Now I know how to get out of it, Thankyou so much :)
Love your work Quadcopter 101, great tip. I also noticed this when I was learning to fly quads but I never knew why it stops the wobbling till now. Thanks for explaining the vortex lift.
I have experienced this and I sure do appreciate the explanation sir! THANK YOU!
Just learned about how to get out of the vortex ring state, avoidance has been to move towards me and descend slowly.
Thanks for the info on VRS. I kept having it with my syma x11c and thought it was a fault or lack of power so I kept jamming on the throttle full, making it worse!
Yep, VRS is a big problem as weight is added to a quadcopter. Just did the following video of a newly released micro quadcopter with HD camera yesterday. The first crash was VRS due to the weight of the camera. Even knowing that it was VRS and what to do, I still couldn't slide out of it before meeting the ground. th-cam.com/video/rjYIE63ZZ94/w-d-xo.html
wow thanks just getting into quadcopters and really learned several things from your video
My 250 sized racer quad is always shaking when descending vertically, what could be the cause of that? Another unwanted flying "effect"?
Thanks for this video! I wish I had seen it sooner as in BEFORE I lost my F100 while flying FPV. I'll be sure to practice this more!
wow, that explains the weird "wobble and fall" effect very well, i was wondering why that kept happening to me
I usually don't comment on TH-cam but this video came out to be very helpful..
Another tip to get out of VRS. If there is a breeze and you are descending, always pitch AGAINST the wind direction instead of with it. So forward pitch may not be the answer if you are facing forward with the breeze. If you are moving WITH the breeze and descending, the wind speed can negate your actual speed and the quad will act as if it is descending vertically with no breeze and enter VRS. Does that make any sense? Don't know if I explained it well. Anyway, good video about the VRS effect! Happy flying!
You are absolutely correct. Fixed wing models need to start into the direction the wind comes from. It is very easy to understand, that higher pressure in the direction you are flying results in higher pressure underneath the propellers.
thank you - first and best info I've gotten on this
This effect crashed my phantom 2 twice (the first time in a river :/ ). I thought that was a defect of the quad, I was going to sell it or something. THANK YOU !
Thank you for the useful info and advice!
Didn't know about RVS, now I do!
VRS, that is :)
I knew something was up with my way of descending my quadcopter! Thank you for this video
I had that happen lots of times with a skyViper v2400. I thought it was faulty and returned it. Now I know , Thanks again.
excellent, very interesting, have noticed same VRS effect (although much milder) without fully understanding what it was. thx!
It depends on how weighted down the quadcopter is. You see it much more frequently and severely with camera quads. Unfortunately, this is especially true for the high cost ones loaded down with GoPros and gimbals Look in the right column of recommended videos to see what I mean..
Great video. I wish I could see the radiocontroll though in the same time. But its really great. It sounds so Easy. But The only time I been into this so called vortex is when I've done a flip. :-) SO that means if I do a flip I kinda have to make it move in the same direction as the flip to prevent it from a vortex is that corrext understod. So a forward flip must still be forward.
Good video. Now, i have the Syma X5C-1 model and when it gets high (about 100meters) i take it down by closing the throttle completely and opening it again about 10 meters of the ground. Never had that VRS problem. But, i noticed it 2-3 times when doing flips at very low altitude just 3 meters above the ground. Maybe some quads are more sensitive to that than others.
Wow, that's a really helpful explanation and demo. Thanks!
The video is great and gives great tips to operators, but seems to have two misunderstandings. First is translational lift, which occurs from the aircraft moving forward. It works due to the rotor being tilted toward the air it's moving forward into. Air has mass and you're increasing the mass flow through your rotor. You're also reducing the effect of wing tip vortices by moving away from them and having the air you're moving into blow into them reducing their effect. All lift is created by newton's second law, to move a mass up you have to push a mass down. The more mass you can push down and have most it go directly in the direction pushing means you can create more lift.
The second thing is the description of a vortex ring state. A vortex ring state occurs from the upward moving air near the rotor hub during hover or decent, and the increasing size through momentum of air created by the wing tip vortices. The vortices get larger without lateral movement and capture and inflate the upward movement of air near the hub during descent. The reason air can move upwards near the hub is due to the slower speed of the blade as you move closer to the hub and is caused by the aircraft's descent or by vortices increasing in size until the upward moving air from them can overcome the slower moving air near the hub.
To visualize a vortex ring of air think or the vortices creating a donut of air near the wingtip. That donut can grow during hover. Now hopefully you can also see why lateral movement gets you out of it
Really noticeable with the Hubsan X4C - I always reckoned this was because of the small blade size compared to the weight of the quad. Now I have a name to put to the effect :)
About translational lift, I always have to throttle up to maintain altitude with a steeper angle of attack, which makes sense to me because the air isn't being pushed straight down anymore. Does translational lift only apply with subtle drifting?
Thank you very much. i am new to the quad-copter scene and thought i was doing something wrong but didn't know what lol. Now i know thanks to your vid. I have put some vids on myself from my flights and without sounding cheesy , i have used your vids to learn a lot of flight craft. Also i am waiting for my new v666 to be delivered and it was your test that made me pick that one from all the rest in the price range . Many thanks and keep going. ;-)
Yep - Experienced VRS with my new X8C today.. Twice! I got out of it the second time - Remembered to go into horisontal flight and get into clean air! Scary how quickly these things come out of the sky!
Gareth James Out of curiosity, were you flying with a camera other than the stock?
yes i've installed a Sj4000 with a gopro style antishock mount.
This VRS effect is also present when taking off vertically, right?
No, You should only see it when it is descending vertically on a calm day.
no just on descending .its like a hole in the air effect