What Do Planes Drop On Fires | FlightNotch

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Key Takeaways

  • Aerial firefighting is essential in controlling wildfires and assisting ground crews.
  • Phos-Chek is the most common substance used in aerial firefighting.
  • The substances used are designed to reduce heat and slow the spread of fire.

If you’ve ever seen a plane fighting fires, you might be wondering what they drop on the fires. Learn how planes put out fires in this complete guide.

Planes use a number of retardants and materials to put out fires, but the most common one is Phos-Chek, which is a combination of water and fertilizer that efficiently suffocates the flames. Planes also drop water, other chemicals, foams, gels, and more to fight fires.

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Table of contents


How Firefighting Aircraft Combat Wildfires

When wildfires occur, firefighting aircraft play a crucial role in assisting ground crews to control and extinguish the flames. In this section, you'll learn about different types of firefighting aircraft, their functionalities, and how they help in combating wildfires.

Air Tankers

Air tankers are specially designed planes used for aerial firefighting, especially common with the U.S. Forest Service. The primary function of these aircraft is to drop large amounts of water, fire retardant chemicals, or a combination of both on and around wildfires. These planes can typically hold between hundreds to thousands of gallons of firefighting substances.

Some air tankers you may have heard of include the Grumman S-2, a vintage aircraft that has been restored for firefighting operations, and the DC-10, a massive plane used by the U.S. Forest Service. The purpose of using air tankers is to slow down the fire's spread, providing ground support with valuable time to extinguish the flames.


Helicopters play an essential role in aerial firefighting as well. Some of these helicopters are equipped with tanks, known as helitankers, while others carry buckets to scoop and drop water on fires. Helicopters are often used in situations where an air tanker might not be suitable, such as in steep or uneven terrain.

An example of a helicopter used in firefighting operations is the Erickson AirCrane, which is outfitted with a front-mounted foam cannon. This versatile firefighting helicopter can apply water or foam directly to fires, providing added support to ground crews.

Single Engine Air Tankers

Single Engine Air Tankers (SEATs) are smaller firefighting aircraft that usually have a single engine. These planes are more nimble than their larger counterparts, making them ideal for navigating difficult terrain and reaching remote areas affected by wildfires.

SEATs can carry smaller amounts of water or fire retardant compared to larger air tankers, but their agility allows them to play a crucial role in firefighting operations. These smaller aircraft are often deployed alongside helicopters and larger air tankers to create a comprehensive aerial attack against wildfires.

Throughout a wildfire, firefighting aircraft like air tankers, helicopters, and Single Engine Air Tankers work together with ground crews to battle the flames. The combination of these various types of aircraft and their unique capabilities helps make your local firefighting efforts more efficient and effective in protecting lives and property.

What Do Planes Drop on Fires?

When planes are deployed to combat wildfires, they use a variety of materials to help extinguish the flames. In this section, you'll learn about retardants, water, foams, and gels.


Retardants are chemicals used to slow down or stop the spread of wildfires. These substances are typically dropped from aircraft, like water bombers, and can be used to create a barrier between the fire and flammable materials, such as dry vegetation, so they don’t catch fire.

The most common fire retardant dropped is Phos-Chek, a mixture of ammonium phosphate, a thickener, and water. This slurry is often dyed red to help the pilot see where they've already made airdrops. So if you’ve ever seen the red stuff getting dropped on forests, this is the chemical you’re seeing!

Phos-Chek comes in powder form and is mixed with water before being loaded into the planes. The ammonium phosphate in Phos-Chek acts as a fertilizer, which helps the vegetation recover after the fire. Anything that helps put out fires while also helping to regrow the land is about the best-case scenario you can hope for during a wildfire.


Water is an essential element in firefighting efforts, both from the ground and the air. Aerial firefighting planes, also known as water bombers, can scoop up water from nearby bodies of water, such as rivers, lakes, or streams. Dropping water directly onto the flames or along the edges of the fire (often called perimeter solutions), can cool the area down and prevent the spread of the flames.

Helicopters can also be equipped with Bambi buckets, which are large containers used to scoop up water from nearby sources and transport it to the fire. The rapid and precise delivery of water helps to contain the fire and protect lives, property, and the environment.

Foams and Gels

In addition to retardants and water, planes may also utilize foams and gels to help extinguish wildfires. These substances are mixed with water and applied to the fire from the air.

They work by creating a barrier between the fire and the fuel source, helping to starve the fire of oxygen and prevent it from spreading. Foams and gels may be used when water alone is not sufficient to control the fire.

By combining these various materials — retardants like Phos-Chek, water, and foams and gels — aerial firefighting efforts can make a significant difference in controlling and extinguishing wildfires. Effective use of these substances can save lives, property, and the environment from the devastating effects of forest fires.

Impact and Effectiveness of Aerial Firefighting

Aircraft Pilots and Crew

When it comes to fighting wildfires, you might notice the important role that aircraft pilots and crew play in the process. These skilled individuals work together to drop water or fire-retardant chemicals on and around the fires, contributing to the overall firefighting efforts.

Aerial firefighting requires a high level of coordination and communication between pilots, crew members, and ground support personnel to ensure the safe and successful execution of operations.

Ground Support

As you watch the aerial efforts unfold, don't discount the vital role that ground support plays in firefighting. While pilots and crew soar overhead, ground crews work hard to protect property, create fire breaks, and extinguish hot spots. These firefighters often brave challenging conditions, including intense heat, smoke, and rapidly changing fire behavior.

Aerial firefighting relies on the combined efforts of both air and ground personnel. This cooperation ensures a more efficient and effective response to wildfires, helping to better protect lives, property, and the environment.

Environmental and Health Effects of Firefighting

When it comes to firefighting, planes often drop a red substance known as Phos-Chek to help contain wildfires. It's crucial to discuss the potential environmental and health impacts of using such chemicals, especially concerning their toxicity and effects on vegetation, aquatic species, and humans.

Phos-Chek, a fertilizer-based liquid, is considered safe for humans and mammals. Most experts agree that it's not harmful, although it can create quite a mess when dropped from planes during wildfires. It's important to keep in mind that you might face some inconvenience due to the mess, but rest assured, your health won't be compromised.

In terms of the environment, there is an associated risk with using fire retardants like Phos-Chek. One of the main concerns is the potential harm they can cause to vegetation and aquatic species. When applied in large quantities, these chemicals can end up in rivers, lakes, and other water sources, negatively impacting aquatic life.

Therefore, it's essential to understand that while fire retardants can help quell wildfires, they may also have some unintended consequences for the environment.

Although fire retardants can affect aquatic species and vegetation, their benefits in controlling wildfires often outweigh their potential harm. By acting as a direct firefighting agent, these chemicals minimize the loss of forests, homes, and lives, which is especially important during massive wildfires.

To sum up, using Phos-Chek and other fire retardants has its pros and cons. While they play a significant role in controlling wildfires and are generally safe for humans, you should be aware that some environmental consequences could result from their use, especially concerning vegetation and aquatic species.

Remember to always keep yourself informed and stay safe during wildfire season!