Winter is coming and suggestions to assist your flying then

[solentlife]

Winter is coming to the North Hemisphere, with it the inevitable cold temps and for many snow / ice.

I fly in the Baltics where temps drop to -30C at times.

We read plenty about cold batterys and IMU - with FW preventing flight when either is cold.

First I would suggest that calibration of the IMU be made in cold conditions - my way is to take the AC outside in the cold and let it cool ... battery is in my pocket staying warm. I then power up everything except the AC so all is ready for when I power up AC.
Quickly powering up the cold AC - I immediately go to IMU calibration ..
The trick is not to let the AC warm up before getting calibration active.

That is a very important step as now with a colder reference calibration - start up of the AC should now be short.

Now onto battery - which is the opposite, it needs to be warm.

There are various suggestions for this :

1. Keep in pocket so body warmth is used.
2. LiPo warm sacks such as the Turnigy unit : Turnigy Programmable Lipo Battery Warmer Bag (12v DC) : can be powered from your cars ciggy socket or any 3S LiPo
3. Insulated picnic bags with addition of pocket warmer if needed - keep in inside house to warm up and be loaded. Make sure closed after taking battery out. Any battery just out of AC can be 'marked' and placed in the bag as they are usually at good warm temp after flight... this helps keep things up in temp.

I use a combo of 2 + 3 and never have any trouble flying in conditions well below -10C ...

Last thing is YOU the pilot and using the controller / tablet. With the screens being out in the cold - they get more difficult to tap and use. The screens themselves do not like the cold. So its a good idea to get well versed on using the controller switches / buttons etc.
For your hands - you can buy Touch Screen gloves that have special tips - they work - but again back to screen being cold.
I do not like gloves when flying - but use thin gloves that still alllow me to 'feel' the sticks, giving me about 20 mins before fingers start to 'tingle'.
Do not forget feet ! You may not use them to fly - but standing on cold ground can be uncomfortable...

I hope the above helps some to get those marvelous winter shots that really make it all worth it.

Nigel

 

[Chrislaf]

Hi Nigel,
I was thinking about starting a thread like this to share suggestions/tips but you beat me too it.

I like your suggestion about the IMU calibration. I think I'll try it as my P3S takes a long time to warm up - probably around a minute or more and on really cold days the battery is just sitting in the AC getting colder while I wait for IMU to warm up.

Yesterday, I was out flying and it was cold (0ºC) and there was heavy wet snow falling. Everything worked fine but the AC and controller got a bit wet. I used my transmitter mitt on the second flight so it kept the controller from getting more wet. I learned on that flight that I can't fly into wet snow as the camera gets gummed up and stays that way until cleaned. If I fly with the snow (same direction it is blowing) or perpendicular to it then the camera is fine and stays clean. Also, flying with the camera pointing down works too.

I also don't like flying with gloves but will need to use thin ones even with the transmitter mitt on cold days otherwise my hands will get cold and its hard to get them warmed back up again.

Having a Spark with folding props makes me appreciate their value in cold weather conditions, whereas with my P3S, I have to spend time spinning on props. This adds delay in launching and fingers getting cold. Unfortunately, my P3S works better than my Spark in cold weather.

I would love to be out flying today. We are getting snow squalls (up to 10cm) but it is very windy (71km/h).

Chris

 

[3rdof5]

I would suggest keeping your flight actions smooth and non aggressive for two reasons:
1 plastic becomes more brittle when cold so sudden prop speed changes are best avoided to avoid stress cracks.
2 The AC battery will have reduced abilities and a sudden power draw has a more likely chance of lowering the voltage momentarily to a dangerous level which could lead to a battery shutdown.
I recommend flying on the top half of the battery and then head for home to be safe in very cold weather.

 

[solentlife]

If anyone wants to add or suggest alternatives - please go ahead. I made the post as a starter to encourage those who fly in winter to encourage others to have a go in what can be some of the most spectacular scenery of the year.

My suggestions are just that ... and do not address all issues.

Nigel

 

[crash480]

I was thinking about flying in the cold too. Never thought of restrictions and special circumstances that we might need to follow

Another Chris from Canada

 

[solentlife]

The point is that when your Phantom is calibrated for summer - it means that the IMU will want to warm up to the temp IMU was at when calibrated.

The act of calibrating when the Phantom is 'cold' is a well known item.

That leaves the battery to be warm so you have minimum wait time when powering up.

That leaves you the pilot and the touch screen.

There are claims about shorter flight time ..... after many years of general RC - I do not see that same reduction with the Phantom as I do with general RC ... yes there is a small reduction but to be honest if you are flying to 15mins or so .. then you should be able to still fly to that. The reason is the AC system monitors the battery and systems unlike general RC that has no FW that does that ...

Nigel

 

[Chrislaf]

We've been getting some snow this week which makes for some nice photo opportunities. Flew both my Phantom 3 Standard and Spark yesterday. It was -4ºC with a wind chill of around -9ºC. Everything went well - flew 3 Spark flights and 2 P3S flights. Hands got a little cold since I had to remove my thin touch capable gloves to spin on/off P3S props and to hand catch.

This worked ok for those temps but for colder days, I think I am going to have to make some modifications to my flying habits. In addition to using hand warmers in my gloves, I am going to more likely land on some sort of landing pad since I don't feel safe hand catching with gloves on - there is just not as much fine control and grip. The landing pad I currently use is one of those circular fold up ones that can be pegged down. In any other season this works well but in winter, the ground is frozen or the deep snow is not firm enough to get the pad secured down. The gloves I used are made for touch screen use but often it is hard to hit small targets (menus, camera settings, etc) on my iPhone 7.

The biggest problem I have, is having to remove my gloves (hands get cold) to spin on the props on my P3S. I tried it with my thin gloves and the motor hold tool and although it worked, I worry about not securing the prop properly since it is harder to feel how tight it is with gloves.

I really have not noticed that much difference in battery time. As long as I keep my batteries warmed up beforehand, the AC keeps the battery warm in flight and flight time is almost the same as in any other warmer season. I have a battery case for my iPhone and this has been working well so far keeping my phone battery topped up so it doesn't shut off prematurely.

Here's a shot from yesterday.

Chris

View attachment TinyPlanet Panorama 1 Line 5 Skidoo Trail.jpg

 

[Nightwolf]

If anyone wants to add or suggest alternatives

Move

 

[solentlife]

For a landing pad ... its actually not necessary to have a 'pegged' pad ... only if its lightweight.

An offcut of heavy Hessian backed carpet will do fine ... no need to peg it down ... its heavy enough to resist the prop wash blowing it around.

My piece is cut to fit the case .. but that does mean precision landing !!

I tried vinyl floor - but when it gets cold - it doesn't flatten out after rolled up.

Another is a folding picnic table ...

Nigel

 

[3rdof5]

Here's my first ever winter flight. Just want to preface this with this was also my first flight farther than 5 meters of myself since my AC was repaired and returned to me from DJI. And also my first flight ever at this location so I am being very careful and staying close. I learned all was well though with no issues with signal or battery so next flight will be more impressive. And yes that's my landing pad in action lol.

 

[solentlife]

I read often - people concerned about winter flying. Really there is no need to be afraid of it. Even when snow starts to fall during a flight ... as long as its not serious snowfall - its fine. The propwash and flight itself serve to help look after the AC. Of course do not overstay your welcome in the sky once snowflakes appear ... bring her home and brush off the flakes ...

Now here's a tip you rarely will find ...

When you finish a flight in the cold - your AC actually is at a greater temperature than the surroundings. If you remove the battery immedaitely - the cooling is more rapid and you can have moisture accumulating. Better to leave the warm battery in until you get to a warm environment - such as in the car or home. The battery will slow down the AC FC board internals cooling to similar rate to itself. It may not make a big difference for odd flights - but if you are a regular winter flyer as I am ... then leave that battery in till you get to warm area.

Unless of course you are going to fly again.

Nigel

 

[Blade4]

I read often - people concerned about winter flying. Really there is no need to be afraid of it. Even when snow starts to fall during a flight ... as long as its not serious snowfall - its fine. The propwash and flight itself serve to help look after the AC. Of course do not overstay your welcome in the sky once snowflakes appear ... bring her home and brush off the flakes ...

Now here's a tip you rarely will find ...

When you finish a flight in the cold - your AC actually is at a greater temperature than the surroundings. If you remove the battery immedaitely - the cooling is more rapid and you can have moisture accumulating. Better to leave the warm battery in until you get to a warm environment - such as in the car or home. The battery will slow down the AC FC board internals cooling to similar rate to itself. It may not make a big difference for odd flights - but if you are a regular winter flyer as I am ... then leave that battery in till you get to warm area.

Unless of course you are going to fly again.

Nigel

Thanks Nigel... I was going to say. If going to fly a gain yes! Pop in a FRESH and WARM BATT as soon a possible and even fire up the motors just to keep those electrons flowing nice and warmly inside the aircraft to keep all the electronics somewhat warm.

 

[Blade4]

Just to add an additional ditto. I have been flying quite a lot in the Winter up here in Minnesota. My work flow is centered around my home or my car. I get my car TOASTY inside. All my batts are kept inside. WARM! Uber important. When I swap, I do so very quickly even if I have to launch right away and safely hover for a few minutes while I set up whatever for whatever. Shot, mission, etc. Best to keep AC and BATTS warm.

I have not noticed any difference in flight time except for one time. I got called away on my job to travel. Yep I left my BATTS full charged and thankfully I have them set to a 3 day auto discharge setting. No harm no foul. Whoops.

Knowing that the BATTS auto discharged down below 65%, I wanted to discharge them down to zero to reset the software inside the batteries then do a full charge, discharge down to 50% for storage.

Sounded like a sound plan. When I took the batteries one at a time up for a quick flight in -5C weather all kinds of weird happened and I saw all sorts of battery issues you hear some people talk about when they are talking against cold weather opps. Rapid Discharge... Yep. Odd Cell behavior... Yep. And a few others.

REMEDY?

Fully Charge all BATTS. I took them right off the charger, and put them into my birds. P4P and P4A. Not at the same time that I will admit to. I then hoover tested them and had absolutely NO ISSUES at all. Every flight was 25 Minutes. I will not go below 20%. I am on the ground by 20% no if ands or butts. That 20% if there incase I really blow it and get into some kind of trouble I have that to get home with or land where I know I can find my drone.

So I have put on about 15 hours of testing my BATTS and ACs and I have flown down to -25C with no trouble. My only issue with that is what was posted earlier. The colder plastic becomes the more unknown we are when it comes to structure failures of all kinds. I can at least say there were no BATT issues down to those temps.

I will stick with DJI and adhere to there temp recommendations due to structure more than battery.

 

[tcope]

That is a very important step as now with a colder reference calibration - start up of the AC should now be short.

Here is a question... should the IMU be calibrated to the _outside_ temp or its _normal_ operating temp? The fact that it takes longer to warm up might not b a bad thing as it is simply being allowed to get to its normal operating temp.

Let me break this down with some hypothetical numbers...

Lets say that the IMU operates at 100F normally. In the summer it starts at 80F and it take little time to get to 100F. In the winter it starts at 30F and takes a long time to warm up to it's normal 100F. So what you do is calibrate it when it is at 50F so it only needs to get from 30F to 50F before you start flying. But then it continues to warm up from 50F to 100F while you are flying. There is a reason why it stops you from doing this.

Just food for thought.

 

[3rdof5]

I did a cold IMU calibration outside on a known level surface. Outside temp was about 40F. Flew yesterday at 30F and I placed my P3P on its landing pad and powered it on first. By the time i had connected my tablet to the RC and powered it all up the AC was ready to fly. Very short warmup time.

 

[3rdof5]

Here's my flight from yesterday, I'm abit more confident this time lol. I've flown much farther away than I did here but that was in summer over open fields. Always abit nervous over water in cold conditions but no issues at all so far.

 

[Nightwolf]

Here's my flight from yesterday, I'm abit more confident this time lol. I've flown much farther away than I did here but that was in summer over open fields. Always abit nervous over water in cold conditions but no issues at all so far.

Boy, that looks cold

 

[3rdof5]

Boy, that looks cold

Lol looks colder than it is. Temp was around 0C or 32F. Much warmer than many others here have flown in.

 

[Chrislaf]

Today I calibrated my P3S IMU in cold temps (-14ºC) and I used the suggestions that Nigel outlined in post #1. I later went out for a flight and the IMU seemed to warm up faster. I will still need to test it out more to see if it actually does start up faster. Before, I was waiting for about 2 minutes for the IMU to warm up. So Nigel, thanks for the great tip about the cold weather IMU calibration.

I did two flights (had the AC follow me while I was X-country skiing). When I landed to swap batteries, the second battery was too cold even though I had it in my Turnigy battery warmer so I had to wait for it to warm up in my pant pocket. I probably need to buy a new LiPo for the battery warmer - the one I was using is about 3 years old and is beginning to swell so it is likely not very effective.

Aside from the second battery being too cold and me having to get myself a rubber landing pad everything worked fine. My fingers got a little cold when I was getting everything set up to get going but after a few minutes of skiing, I was toasty.

Chris

 

[3rdof5]

Today I calibrated my P3S IMU in cold temps (-14ºC) and I used the suggestions that Nigel outlined in post #1. I later went out for a flight and the IMU seemed to warm up faster. I will still need to test it out more to see if it actually does start up faster. Before, I was waiting for about 2 minutes for the IMU to warm up. So Nigel, thanks for the great tip about the cold weather IMU calibration.

I did two flights (had the AC follow me while I was X-country skiing). When I landed to swap batteries, the second battery was too cold even though I had it in my Turnigy battery warmer so I had to wait for it to warm up in my pant pocket. I probably need to buy a new LiPo for the battery warmer - the one I was using is about 3 years old and is beginning to swell so it is likely not very effective.

Aside from the second battery being too cold and me having to get myself a rubber landing pad everything worked fine. My fingers got a little cold when I was getting everything set up to get going but after a few minutes of skiing, I was toasty.

Chris

Cool did you get video?