Flying over snow advice?

[KiterTodd]

I have read several helpful threads and watched several vlogs about flying the Mavic over snow. Thus, I think all of the cold temperature warnings (batteries for all devices, prop icing) is covered as are the notes about being conscious of altitude causing the Mavic to work harder. I've also read great tips on ND filters and touch screen friendly gloves.

Any other advice we should know prior to flying over snow covered hills at high elevations? ~9K' to 13K'

Will the front vision sensors see a white hill in front of it?

Will the bottom sensors get confused by minimal contrast below? I suspect I'll have to assist with landing, but I was wondering if during normal flight it's going to get disoriented, even though it has GPS lock? I had read warnings about flying over reflective or low constrast landscapes like water & snow.

Thanks in advance for any knowledge shared.

 

[AyeYo]

Front vision should be disabled. Any glint of glare off the snow and you'll be coming to a screeching halt.

Downward vision can be left on without creating issues, but don't expect it to do anything useful (e.g. it's not going to stop the Mavic from landing on a snow pile and tipping over, because everything looks the same). This doesn't seem to affect position hold with good GPS lock though.

Performance is obviously sluggish at 13k+ feet, expect very lazy climbs and don't go charging at any hills because you won't make it over.

Shorter battery life should be obvious. Prop icing actually isn't an issue unless you're flying in sub-freezing fog/clouds.

In general this thing just exhibits all kinds of errors and weird behavior (mostly with the gimbal) when used below freezing, so go in with the expectation that you're going to have shots ruined, because it's going to happen. It'll save you some frustration.

 

[TeamDaedalusDrones]

Practice hand launch and hand landings or use a large landing pad. The powder snow goes everywhere as you get close to the ground to land. If it finds its way into the cracks and crevices and turns to water near those electronic components, there could be future issues.

 

[KiterTodd]

The only way to disable front vision is by enabling sport mode, correct?

 

[saudio]

The only way to disable front vision is by enabling sport mode, correct?

Nope, there is a menu item to disable the front sensors. It gives you about 10MPH more speed and you can still use intelligent flight modes. If I'm not flying where there are obstacles I always turn them off.

 

[KiterTodd]

Figured I'd close the loop now that I got back from my trip and have gotten to play with the footage a bit.

I probably didn't end up flying above 10K' and temps were mild so I didn't have battery issues, however, I did always keep the batteries warm with hand warmers as suggested in another thread.
I also bought one of those collapsable landing pads which worked great. I am not comfortable hand launching/landing yet and I found the pad target made it very easy to land... just point the camera straight down, and from your screen you could see when you were in the center.

I also didn't turn off VPS but probably should have. The Mavic return to home was always a little bit off... maybe 5' off when it is usually dead-on. Also, when it was flying it wouldn't hold altitude and position as steady. It'd kind of fly drunk. Not offensively, but there would be slight unexpected altitude or lateral adjustments that I don't normally see.

This video starts with a bird encounter I mentioned in another thread, then I included a bunch of clips from the same trip. Be open to feedback, it was my first time flying with the intent to edit the footage. So I learned a lot looking at my footage on how I'll control motions and such next time.

The snow footage was filmed without a filter. I brought a Polar Pro out with me but had issues with it so didn't use it. I was impressed with how well the Mavic did capturing contrast of the snow and the sky colors without any filters. Note, none of this is color graded or matched, I'm sure I could enhance a good bit of this.

 

[amandataylorart]

I live in Michigan and I love the footage my drone gets in the winter BUT I have had many problems with the sonars and GPS(at 17 satellites) with my drones movements becoming unpredictable. Its decent when its 50ft up but anything close to the ground and it freaks out. I can stabilize it somewhat when its having a spa but it makes it impossible for getting the shots that I need. It's not me as a pilot because I have over 150 hours of flight time. Is there any fix for this?

When it comes to temperature: The coldest I have flow my Mavic Pro is in 16 degree Fahrenheit and it surprised me on how well my battery kept up including overall performance. I had a solid 25mins of battery. I do experience a lot of feedback problems and signal problem in general in the snow at different locations.

 

[KiterTodd]

Just had it out west again on a Wyoming trip. This time the temps were cold and I was definitely flying it between 9K and 10.5K altitude. I probably flew it from -15 degrees F to +15 degrees F.

The Mavic had no problems with the cold. It really flew well and I did not feel like my battery life suffered at all. If I got a cold battery warning on startup, I'd just let the Mavic hover until the batteries warmed up. I would also turn on the props as soon as the controller connected to the Mavic (before I had my iPhone out) in order to get some power going through it. I'd take-off once I had the phone connected as that display could give me battery cell temp info.

The issue I had was with my iPhone! I would keep that in a coat pocket with a toe warmer stuck on the back of it and a larger hand warmer packet in front of it. That would keep the battery power normal while I was traveling around but as soon as I took it out to film that is when the issues started...

...I'd keep the stick-on heater on the back of the phone, but the cold would get to it. My screen would abruptly go black and the phone would shut off well before my Mavic battery was consumed. Once that happened you had to hope the Mavic was in sight or your RTH button was functioning! Still got some great footage, and to be honest, on the coldest days when the iPhone would black out... that was usually all my hands could take anyway so I didn't mind landing.

I found that I couldn't really fly the Mavic with thick gloves. I would wear thin glove liners but the cold would eventually get to my fingers as well.

All in all, still a great craft to fly in a wide variety of conditions.

FWIW, there was another guy on this trip who had a Mavic and he also had some knock-off batteries. I didn't even know they existed. The knock-off batteries could not handle the cold at all. As soon as he launched the battery would be too low to fly and he'd have to land. ?

 

[tictag]

Some really lovely footage there, love snowy scenes and by air they are just fantastic! One quick tip regarding exposure. Most digital exposure systems compare midtones to an 18% gray reference and shooting a standard city scene, for example, this is fine. When your entire frame is basically white, however, comparing to 18% gray under-exposes the image - this is why your snow looks gray. To fix, simply manually expose about +2EV for bright skies, maybe +1EV for overcast skies. For accurate results, over-expose the image and notice the white clipping in the histogram (far right vertical line), then dial it back until the clipping disappears. Result> white snow.

 

[KiterTodd]

Anyone have advice for keeping the phone from freezing in very cold temps?

You almost need an oversized phone case with a cavity behind it where you could cram two mitten warmer packets. I'm sure I could jury rig something, but you can't have any rubber bands or anything blocking the screen.

To clarify, these were COLD temps. You'd go from a 80% charge warm phone from your pocket to a complete black shut down with no warning in less than a minute. Cold.

 

[tictag]

You can get those LiPo handwarmers off Amazon (for example: http://amzn.eu/3ojCEMP) and somehow stick to the back? The actual heating element inside is just a thin, flexible PCB ... if you're OK with hacking, maybe stick these films to the phone back? Added advantage of having the battery pack with you is that it can also charge your RC!

As a further hack, these handwarmers use 18650 LiPo cells, which are round and bulky, but you can get flat cells for a lower profile. Maybe a product idea there!!

 

[barbhav]

Today I decided to take some nice drone shots during a light snowfall. The mavic pro operated fine for about 5 minutes.
Then, it decided to fly off on its own right into a very tall pine tree. I had absolutely no control over it.
It sat up in the tree and did some 29 minutes of video (unprompted). I had to call in an arborist to shake it out of the tree and onto a tarp.
Not a happy day.
So ... Not sure if it was JUST the snow, but my drone was possessed.

 

[Flycaster]

You also might want to use some day-go orange tape on the arms/body, just is case it decides to "go skiing".....

May help you locate it in the white...

 

[FatherXmas]

There was a few posts last winter that if you put a thin coat of Rain-X on the props, it helps keep them from icing. I tried it last year, don't know if it actually kept the ice off or not. The props never iced, but was the Rain-X what did it? Anyway, it doesn't hurt.