Water Crash... Is this the VPS issue im now reading about?

[JJM]

Did the new firmware update now allow you to once again cancel landing with just up stick?
Also seems the VPS has the most issues when flying over very calm water (mirror effect) and/or low to the water.

No offense but did you even bother to read? Haha The answer to your question is in the post right above your question. It's also in the thread titled "new firmware".

The answer is no.

 

[Bigpoppapump]

Can you turn off VPS in Litchi? Or neutralize landing protection or equivalent?

 

[GerdS]

Hey guys, wow, all this stuff is interesting, I was flying over water today, should I turn off the Vps...if so, will I still have precision return to home. I scuba dive and will use my mavic a lot over water to film dive boats and divers, practice today no problem, but reading this post makes my bloody nervous, any advice please.

I guess it depends on your altitude and on the height of waves. Higher than 10m there should be just no problem at all with sensors enabled.
If you are flying lower, then the VPS system may report wrong movement data due to the moving waves which tell the Mavic it would be moving while it doesn't according to GPS. So VPS should be better turned off in this situation.
With Landing Protection I would assume that the ultrasonic sensors will report the actual altitude above the water surface, but may get confused with high waves, as the altitude is changing with each measurement although the barometric sensor tells altitude is same.
Above flat water I would assume that Landing Protection is helpful by preventing the Mavic from landing on water by accident, as it will stop a descending in a safe altitude of some feet. It is just the duty of the pilot to detect that his commanded descending has stopped and then he must not pull the throttle stick down any longer to avoid autolanding.

 

[ChasiTail]

I guess it depends on your altitude and on the height of waves. Higher than 10m there should be just no problem at all with sensors enabled.
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I'm not so sure about that. When my mavic was at the 150' height the VPS was still reading 0.7' So even at higher altitudes it would seem that the VPS does not show accurate info over water. Or at least it didn't in my flight that went into the water. Of Course I may have had a faulty sensor as it seemed to be working fine for the first 3/4 of my flight when I was only 25-40' from the water.

 

[Strafe1]

I'm not so sure about that. When my mavic was at the 150' height the VPS was still reading 0.7' So even at higher altitudes it would seem that the VPS does not show accurate info over water. Or at least it didn't in my flight that went into the water. Of Course I may have had a faulty sensor as it seemed to be working fine for the first 3/4 of my flight when I was only 25-40' from the water.

I got no VPS reading when over water at an altitude of 75'. I wasn't lower than that when I was over the water, so I don't know about anything lower than that.

 

[Chris M]

I have a couple of questions related to this...
- What exactly is the benefit of Landing Protection? Based on the manual, I see no purpose for it. If and when I instruct my Mavic Pro to land, I will ensure it's safe to do so. I don't need the Mavic to confirm it with it's sensors. And if it's landing where I can't see it or observe the ground through the camera feed, I have bigger problems anyway.
- What is the point of DVS (Downward Vision System) outdoors? Based on the manual, DVS is an alternative way for the aircraft to hold position in the absence of GPS... e.g. when it's indoors. When outdoors, the craft will use GPS for positioning. I see no point to having this turned on when flying outdoors. In fact, I can see it being a major problem when the surface below has no pattern.

What am I missing here?

 

[Robbyg]

It prevents you from slamming the drone into the ground if you pull down too hard on the sticks. At least that's what I am told. I always turn mine on before I land so I never experienced the problem.

Rob

 

[Strafe1]

It prevents you from slamming the drone into the ground if you pull down too hard on the sticks. At least that's what I am told. I always turn mine on before I land so I never experienced the problem.

Rob

I've turned my off and tested it to be sure. It does NOT land hard. It lands softly. It doesn't have the pause at 0.5m. That's the main difference. I've turned it off for now as a safety measure for aborting forced landing, should I ever need that.

 

[JJM]

I've turned it off for now as a safety measure for aborting forced landing, should I ever need that.

This is the best choice for everyone.

 

[Gucci]

Hey Guys,
From all I have read in this thread, Landing Protection has negative points over water but some benefits over ground. How about if DJI put a customization option of Landing Protection On/Off for C1 or C2 button? Then we can easily change the mode over water and ground.

 

[alex2987]

Hearing this is a real shame as I love flying my Mavic over water. We have lots of beautiful reservoirs here in the UK which are great for photos/videos. I'm starting to become a bit put-off now!!

Good to know about the sports mode trick though for taking control during a forced landing!

 

[JLane]

Hey Guys,
From all I have read in this thread, Landing Protection has negative points over water but some benefits over ground. How about if DJI put a customization option of Landing Protection On/Off for C1 or C2 button? Then we can easily change the mode over water and ground.

To be perfectly honest, I don't even find much use for it over dry land. Even with LP disabled, the Mavic won't slam straight into the ground if you apply full down stick. It still slows its descent as it gets closer to the ground. I've tested it even in Sport mode. From a height of 22m I applied full down stick. It reached a maximum descent rate of 3 m/s, but when it got down to 10m is started to slow that rate. By the time the Mavic was at 2m, the rate was down to about 1m/s. At 1m it was descending at about 0.5m/s and continued to slow 'til about 0.2m/s before it touched the ground.

The only other advantage of Landing Protection is that it supposedly checks for a "safe" landing spot before it completes the final touchdown of an auto-landing. I don't find this overly helpful because 1. If it's an RTH landing then it's usually landing where it took off from, so presumably a pretty safe spot to land and 2. if it's an auto-landing that I've initiated, then I've already decided I want it to land there.

 

[Andrew F]

I'm not so sure about that. When my mavic was at the 150' height the VPS was still reading 0.7' So even at higher altitudes it would seem that the VPS does not show accurate info over water. Or at least it didn't in my flight that went into the water. Of Course I may have had a faulty sensor as it seemed to be working fine for the first 3/4 of my flight when I was only 25-40' from the water.

I vote you were having a hardware fault. My sonar has been very consistent over water. VPS is for lateral movement and I've never had a problem with that and I have flown for many hours low over the ocean.

 

[Kestrel]

I've done the Majority of my Mavic videos over water, I turn my VPS off and never had a problem, even went as low as 3-4 feet above the water.

 

[gixxerbill]

Been flying my mavic around on my 5acre open field since I bought it a couple months ago. No issues ever, everything worked as advertised.

So I thought it was time to take it out on the boat and get some shots of the boat. Everything was going as planned for about 10 minutes of flight. I was in Active Track for much of the time, following the boat around.

I exited that mode, to get video of the boat driving under the drone as it hovered, and that's when things seemed to go sideways. The drone on its own flew up from about 25' elevation to 150', then went into "forced landing" where I could not stop the descent with the stick, or pause or by canceling it on my screen. As it was coming down, I was able to use the RT stick to fly it close to the boat where it splashed into the water. Luckily I was also able to keep the props spinning and kept it on the surface long enough for us to somehow catch the drone with a gaff and retrieve it into the boat. The last minute or so of flight data was the drone going crazy on the surface of the water as I kept the joysticks pinned up praying the drone didn't sink.

I was perplexed as to what happened, and have since been reading about the VPS issue over water, so I uploaded my flight record and sure enough, just before my mavic went crazy on its own, the VPS went from reading correctly, to reading 0.0-0.7 feet, even when the drone climbed on its own from 25' up to 150'. VPS stayed the same, all the way back from 150' to just as it almost hit the water.

Heres my flight log. What do you all think?
Phantom Log Viewer - PhantomHelp.com

What is a VPS water issue? ( i fly over water all the time and am very concerned.

 

[Kestrel]

What is a VPS water issue? ( i fly over water all the time and am very concerned.

The downward sensors see the reflection of the mavic in the water and it starts acting up. Just turn off VPS and everything should be fine.

 

[Andrew F]

The downward sensors see the reflection of the mavic in the water and it starts acting up. Just turn off VPS and everything should be fine.

I fly very low over water with VPS on and have never had a problem. However, it is very clear water with coral reef so that VPS works as intended. I like it because I get rock solid hovering. No wind or gps drift at all. Very nice. But if the water was not clear, it wouldn't provide a value. However, the autolanding / sonar problem is a different matter entirely. I may be wrong, but I think most people have this delineation confused. Sonar "should" be the feedback the Mavic is using to determine elevation and therefore when full down stick should leads to auto landing. But perhaps DJI has this messed up.

 

[Kestrel]

I fly very low over water with VPS on and have never had a problem. However, it is very clear water with coral reef so that VPS works as intended. I like it because I get rock solid hovering. No wind or gps drift at all. Very nice. But if the water was not clear, it wouldn't provide a value. However, the autolanding / sonar problem is a different matter entirely. I may be wrong, but I think most people have this delineation confused. Sonar "should" be the feedback the Mavic is using to determine elevation and therefore when full down stick should leads to auto landing. But perhaps DJI has this messed up.

I do the majority of my videos over water and low to the water, I never tried to fly over water with VPS on because of issues like this thread, I just assume it might happen with the sensors on. I also like the added speed I get with the sensors off, especially when its windy out.

 

[sekine12]

Btw: the Mavic manual clearly states under "Flight Environment Requirements":

The manual also has plenty of statements about what to do when flying over bodies of water.

 

[Saylor101]

I have yet to fly my Mavic over the water after all the horror stories on here. Yet, some people fly all the time over the water with no problems. Some turn off the VPS, some do not. One question I have, and apologize if answered earlier in this thread or else where, is the downward sensors are only active below 13m and that there is no way to turn them OFF except by turning ON Sport mode? And you only turn off the forward sensors with the "vision symbol" on the RC?
So I've read...turn off the VPS, turn off Landing Protection, try not to go full left stick down, stay above 13m...and if it does start to "auto land" go to sport mode asap? Yet some pilots do not do some, or all of that. Yes, the manual has the warnings about flying over water....but we all want to do it. A lot of conflicting information and opinions.