Although for many, January brings colder, unpleasant weather, the summer months will be here in the blink of an eye. Something that should be considered, even now, in preparation for the sweltering months your area may have in store, are tips for flying a drone in hot weather.
Some information and a few useful tips we’ll delve into include:
- When is it too hot to fly?
- The challenges of hot weather flight and the effects heat has on drones
- How to fly longer in hot weather
- How to keep drone batteries cool in hot weather
- The effects of heat on cell phones and tablets
When is it too hot to fly a drone?
This is a very good question and deserves a fair bit of attention. What’s extremely hot for some may be mild to others. However, in the world of drones, there is a defined maximum temperature threshold that drone operators should adhere to.
For most DJI, Autel, and Parrot drones, the maximum operating temperature is 104°F (40°C). This makes sense, as drones are at the mercy of the electronic components inside the drone and, more importantly, the batteries therein.
Flying in extreme temperatures may be dangerous for the drone and, by the laws of cause and effect, to people in the surrounding area.
The challenges of hot weather drone flight
Aside from the discomfort hot weather has on the operator, there are a few aspects of the drone that weather has negative effects on as well.
At first glance, you might wonder, how could hot weather affect the propellers? This is an interesting one, as it deals more with the possible effects the hot day can have on the weather. Simply put, during summer months, or hot weather events, many times, there is accompanying humidity or muggy conditions.
The humid conditions affect the propellers, which in turn, affect other areas of the drone. Without going into too many meteorological explanations, humid air is lighter than dry air, meaning the air has a lower density.
Because of this, drone propellers have less efficiency regarding lift in humid conditions, causing the motors to work harder, thus putting more strain on an already hot battery. We’ll be discussing the effects hot weather has on batteries soon.
Crack open a drone and you’ll see it is packed full of electronics. Without these electronics, our beloved drones would never take off. During nice weather flying, one might not even give it a second thought. Add weather extremes like blizzards or heat waves, and that’s something entirely different. With any electronics, if they are exposed to high-temperature extremes, they begin to fail.
If you leave your phone, or some other electronic device in a hot car with the windows up, you’ll notice it might start acting “funny”. The display might fade in or out or stop working completely.
This is the same when it comes to drone electronics. When a drone gets too hot (above that 104-degree mark mentioned earlier), the camera can be affected, or the drone can start dropping the video stream to the controller. The proximity sensors might also begin to fail, as well as a few other issues with the motors. These can result in the loss of a drone.
This is one of those obscure aspects of flying in hot weather that you just might not think about. The color of your drone can have an effect on it.
How? I’ll illustrate it this way: Have you ever been in a parking lot, barefoot in the summer? If you walk on the white lines in the parking lot, your feet are fine. Step off onto the black asphalt and you might suffer what feels like 3rd degree burns on the bottoms of your feet. The reason being the color white reflects sunlight and heat while darker colors and black absorb sunlight and heat.
This is the same for drones. While many individuals like darker drones for better visibility in the sky, for instance, the Phantom 4 Pro Obsidian, they retain more heat than the harder-to-see white drones, like the standard white color Phantom line. The darker color drones get hotter, thus affecting the interior components a bit faster than the lighter/white colored drones.
Another critical drone component that is affected by hot weather is the camera itself. This is more a combination of extremely warm or hot temperatures and cooler temps. Something to be aware of in this regard is going from your nicely cool or cold air-conditioned vehicle and then flying immediately thereafter.
Because the drone was sitting in the air-conditioned car and then flown in the heat, the camera may develop condensation behind the lens itself and/or the UV filter, should the drone have one.
In this case, simply allowing the drone to warm up and get acclimated to the hotter temperatures will be enough time for the lens to eventually defog. If it’s just the removable UV filter, you can wipe that off and wait a few minutes.
Weather to watch out for
In addition to hot weather being, well, HOT, hotter weather brings with it additional weather conditions caused by extremely warm temperatures. Some of this weather to be aware of would be:
This was touched on earlier in the Propeller section. However, it is good to include muggy/humid days here as well. As a recap, contrary to popular belief, those muggy and humid days cause the air to be less dense than your standard non-humid days.
Because of this less dense air, the drone flies significantly less efficiently, meaning you’ll put more strain on the battery, resulting in shorter flight times.
This one is a bit more serious, on a few fronts, than flying in humid weather. In the United States, the FAA has ruled that to fly legally, the drone must be always within Visual Line of Sight (VLOS), whether visible to you or someone you have designated as your Visual Observer (VO).
When the weather is foggy, there is a higher chance of losing sight of the drone, which could result in a crash, damage to someone’s property, or personal injury.
In addition to losing sight of the drone, flying in extremely foggy weather can result in the drone accumulating so much moisture that water gets into the drone’s airframe and damages the internal electronic components, possibly causing a malfunction and a crash.
If you plan to fly in foggy conditions, consider doing the following:
- Affix FAA regulation “drone anti-collision” lights to the airframe. This will increase the chances for manned aircraft to see your drone AND assist in you being able to keep your drone within VLOS
- Bring extra batteries. Because foggy weather tends to bring with it more humid air, as mentioned above, the efficiency of the drone will be lower, resulting in shorter flight times
- Waterproof your Drone. There are various third-party companies that have solutions for certain drones which enable them to fly in the rain and fog while minimizing or even eliminating water/moisture damage
With hot and humid weather comes the possibility of rain showers or thunderstorms. As a Floridian, this is something I deal with a lot, whether I fly in Central Florida or the Gulf Coast.
Since electronics and water do not mix, it would be best to avoid getting stuck in the rain altogether, canceling your flight plans should you be aware beforehand of a coming storm. More often than not, a soaked drone will result in a broken or unflyable drone.
At times, though, it might not be possible to avoid getting caught in the rain. If this is the case, it is advisable to land as soon as possible, in a dryer and safe place.
As mentioned in the fog section, if you really want to fly in the rain, or have paid jobs that require you to fly “rain or shine”, there are solutions available for many drones to do so.
How to fly longer in hot weather
Up to this point, we have discussed the effects hot weather has on drones and their individual components. Now we’ll go over some tips and areas to be aware of that’ll allow longer flight times.
Keep your cool
As with any outdoor activity, keeping yourself cool and hydrated is essential. It doesn’t matter if your drone is happily zipping by on a hot day, with no problems caused by the heat. If YOU are feeling the ill effects of the heat, that will transmit to the drone, possibly causing inaccurate and unprecise flight. If possible:
- Fly from the cover of shade. This could be under a tree or even a beach chair with an umbrella attached
- Fly from within your vehicle. As long as you have a clear line of sight with your drone, this is a viable alternative. Some drone operators do this, especially in the wintertime.
- Stay hydrated.
Keep the drone moving
As you might have noticed on your own drone, there are various ports, slats, grills, and openings. These are designed to allow the entry of air, helping to cool the drone down on hot days and aid in releasing the build-up of heat.
To keep your drone a bit cooler on those terribly hot days, try to avoid staying stationary over one spot for too long. Staying in one spot does not allow air to enter the drone, to assist in cooling down the interior electronics, making the drone more prone to failure.
Keep your batteries cool
There is a lot of information on the internet, as well as here on Droneblog, that goes into proper battery care, storing batteries at room temperature, and steps to keep batteries from getting damaged due to extreme temperatures.
Batteries that are constantly flown in extreme temperatures, in this instance heat, are prone to permanent decreases in battery capacity, stability, and life. Even if just flying a few times in the extreme heat, the batteries are subjected to working harder, heating up faster and depleting quicker, thus leading to shorter flights.
To keep your batteries cool, you might consider:
- Keeping drone batteries inside your air-conditioned car, instead of in the trunk when en route to and from locations
- After your flight, take the battery out of the drone, as doing so will aid in the battery and drone cooling down faster
- When on location, have a small, empty drink cooler with you and store the batteries in it (no drinks or other moisture in the cooler). Put the ice pack in a freezer bag or two to trap any condensation from the pack, keeping it away from the batteries.
Make sure all batteries are fully charged
We have seen a common theme here regarding batteries and flying in the heat. Heat causes batteries to deplete quicker.
This being the case, it is a good idea to have all batteries charged to 100% to get the most out of them. That 20/25 minutes of flight time we have burned in our minds from normal flights, turns out to be a bit less when flying in extreme temperatures.
Cell phones and tablets
The heat doesn’t just wreak havoc on drone batteries and drone electronics but also on the mobile devices we use to fly them.
I use a variety of devices with my drones: iPads, iPhones, Android Phones, and Tablets. I must say that they do indeed suffer from heat-related issues, especially when I’m flying on the coasts in the summer.
Some of the things I have experienced, and you might as well, are:
- Screen dimming, then going completely black
- The devices becoming too hot to even touch
- Sometimes, the device shuts itself off (with an overheating warning message)
Just like the drone batteries, it is a good idea to keep your electronic devices as cool as possible. A few ways to do this are some of the same things one would do with their drone batteries:
- Keep your electronic device inside your air-conditioned car, until ready to fly (if it is not the one you use to make calls already inside the vehicle)
- Have a small, empty drink cooler with you and store the devices in it
- Fly from the cover of shade
- Fly from within your vehicle
- Remove phone and tablet cases to allow the devices’ heat to properly disperse
None of us want our drones to malfunction, crash or harm anyone. But, as can be seen, with proper precaution and planning, flying in hot weather can be done safely for ourselves, our drones, and those who might be in our vicinity.