With a major wildfire season just behind us, I guess I’ve been paying more attention than usual to the causes of wildfires, so I got to wondering if drones could cause fires. A little bit of research revealed some surprising answers!
Drones have the potential to start wildfires in a number of different ways. One risk is from overheated motors or batteries igniting dry grasses upon landing. They can also be used to intentionally start controlled burns by dropping fire igniters, called “dragon eggs”, in localized areas.
The last thing any of us wants is to unintentionally start a wildfire with our drone. A little bit of awareness and caution can go a long way to making this a very remote possibility. And awareness of how drones can and are being used in fire prevention can inspire hobby drone users to be smart about how and when to fly if they are in high risk or known wildfire areas.
TABLE OF CONTENTS
1. How Drones Can Start Fires
2. Tips for Preventing Fires
3. Firebomb-Dropping Drones
4. Other Ways Drones Fight Fires
5. Don’t Get In the Way
How Drones Can Start Fires
There have been a number of cases of drone crashes that started wildfires, particularly in dry, high wildfire-risk areas such as Arizona or Oregon. So how does a crash lead to setting off a fire? In many cases, it appears to be battery initiated. If the battery shorts out, or is overheated when the drone lands (whether the battery malfunction causes a crash landing, or the drone is landed intentionally), the overheated battery can cause dry grasses, pine needles or other easily combustible natural materials to ignite. If this occurs in a drought-ridden or generally arid area, it could lead to a widespread wildfire.
In some cases the cause of overheating and combustion does not appear to originate from the battery, but rather from the motors. An improperly functioning motor could generate enough heat to ignite dry combustible material in the same way, or could even send off sparks.
In most of the reported cases of drones unintentionally initiating wildfires, the drone in question was a racing drone. This is likely the case for a number of reasons. One reason may be that the motors and batteries of racing drones are more exposed and less enclosed than they typically are in more standard off-the-shelf models. Any issues such as overheating or sparking are more likely to cause problems when less contained. Also, racing drones generally don’t have legs to land on, and would be in more direct contact with potentially combustible materials upon landing than a drone that has landing gear, so to speak.
The risk of fire from drones is not limited to outdoor settings. LiPo batteries are known for their instability and risk of combustion, but if stored properly in a fireproof bag or box when it combusts, there’s not much risk of spreading to home or property. But for improperly stored batteries, there is some degree of risk that they could spontaneously combust and start a fire in your home.
Tips for preventing fires
An ounce of prevention is worth a pound of cure as they say. Exercise a little bit of caution, and the chance of starting a fire with your drone becomes slim indeed.
- Always store your batteries in a fireproof bag or box. Never store your batteries in the charger. It’s also a good idea to keep an eye on your batteries while charging.
- Carefully inspect your batteries and motors for signs of trouble before flying. Look for bulging or corrosion in the batteries, and discoloration on motor coils that could indicate potential problems or hotspots.
- Plan to land your drone on pavement or rocky surfaces, away from easily combustible material. But crashes happen, so have a plan in place for that eventuality.
- Have water or other flame retardant materials on hand to douse flames should any ignite, if you are flying your drone in especially dry or high wildfire-risk areas.
- If you are flying a racing drone, be especially vigilant that you don’t leave behind any sparks if you crash. Watch for a few minutes to make sure no flames have ignited.
- Don’t let things get out of hand. It doesn’t take long for a small fire to become a big fire. If your drone has started a fire that you are not able to immediately put out, call 911.
So far we’ve been talking about ways that you could accidentally start a fire with your drone. But drones are actually also being used to intentionally start fires, all in the name of ecosystem maintenance and fire prevention.
What?! It sounds very futuristic, and the name given to these little fire bombs only adds to the drama. But it’s true. Drones are being used to drop “dragon eggs”, self-igniting plastic balls filled with potassium permanganate. Just before being dropped, the ping-pong sized balls are injected with glycol which initiates a reaction causing combustion within 30 seconds. But why in the world would you want to light fires in fields or forests using fireballs from the sky?
Drones dropping dragon eggs are being used in an effort to maintain areas of Great Plains grasslands that are under threat of overgrowth by trees and shrubs. Historically the plains have been grasslands, and that was in large part dependent on the practices of Native Americans who started fires to improve the grazing area for the buffalo herds. In modern times these methods have not been maintained, and trees and shrubs now threaten to take over the grasslands. Low-intensity, controlled burns have not been effective at removing the woody plants, but it seems that drones with dragon eggs have the potential to provide for the high-intensity, high-heat burns needed to preserve the grasslands.
The dragon egg dropping methods of fire-starting is also being used to help with wildfire prevention. It sounds counter-intuitive, but it is an established firefighting tactic to burn through undergrowth to prevent buildup of potential fuel for an unregulated blaze. This can be done as a regular preventative measure in fire-prone areas, and can also be done as a blackburn to stop the spread of an active wildfire.
Dropping self-combusting little balls sounds tame compared to the other method for which drones are being employed to start fires. It seems they can also be used as flame-throwers, also for the purpose of starting backburns, or to clear dead woody undergrowth.
These methods of dropping dragon eggs, and using aerial flame-throwers are not new to the firefighting arena. They have been employed for quite some time, but until recently airplanes and helicopters have been the source. Drones have the obvious advantage of being unmanned. Especially when large and dangerous forest fires are in question, sending a robotic flying machine into smoke and heat is much preferable to putting firefighters and pilots at risk.
Other ways drones fight fires
Initiating backburns is not the only way drones are being used in firefighting efforts. Drones are also instrumental in providing firefighters with critical information to help with combating a blaze. An aerial perspective can provide information such as the direction and speed of a forest fire, as well as helping to identify natural features that may pose a greater risk, or offer possible solutions in helping to stop the spread of an active fire. Drones easily provide this aerial perspective, again, without the need to put pilots at risk flying through smoke.
Drones can also be used to spray water or other fire retardant chemicals over burning areas, although the relatively small size of a drone is a seriously limiting factor in the effectiveness of this tactic.
Don’t get in the way!
Just because we say that drones can be used to fight wildfires, don’t misunderstand that as an invitation to fly your drone into the next blaze. Specialized drones being used by trained professionals are helpful in fighting fires. A drone hobbyist flying near firefighting efforts is not going to help, and could cause even more harm. The professional firefighters are flying drones, air tankers, helicopters and smokejumpers at relatively low altitudes, often below 200 feet above ground level. This is within the range of recreational drone flight, and if you’re flying there, you could cause a crash at the cost of expensive equipment or even the life of a pilot. So if it’s a wildfire, leave the drone flying to the professionals.