Down to the Last Drop!

By Sam Digiovanna

I love the fire service – so much specialized apparatus and equipment and so many expertly trained personnel to carry out the mission.

One of the top assets on my list of fire service intrigues is air operations – one of the firefighters’ biggest allies during wildfires, remote-area rescues, or patient transports to trauma centers. The pilots of fixed-wing and rotary aircraft perform some of the most incredible maneuvers.

There is no question that pilots face unique stressors and dangers, but it is important to remember hazards on the ground as well, particularly in the presence of firefighting aircraft dropping retardant (gel or foam), para cargo, or water. News headlines capture the dangers (or mishaps) of such drops:

As such, it is vital that pilots consider the optimal retardant safe drop height. The U.S. Department of the Interior explains why: “When the retardant is dropped, the velocity of the aircraft is imparted to the retardant. In other words, the retardant is traveling at the same speed as the aircraft. When the retardant has lost all its forward momentum and is falling vertically like heavy rain, the danger to firefighters is reduced and effectiveness is increased.”

The safe drop height is having been defined as the distance below the airtanker at which the retardant begins to fall vertically. The DOI presents this example: “If a Very Large Airtanker (VLAT) is traveling at 150 knots and is well below the recommended safe drop altitude, the 8,000-19,000 gallons of retardant released will impact the earth at a similar velocity. If personnel are underneath the retardant pattern, they can be struck with the fast-moving retardant, broken trees, other debris, or all of it.” You can read more on this in the DOI Interagency Aviation Safety Alerts.

With this in mind, it should be no surprise that personnel can be injured by the impact of material dropped by aircraft.

Additionally, use caution when working in an area covered by retardant, as surfaces will be slippery. This can be the case on both hillsides and around structures. Water will also make hillsides muddy and cause escape routes to be altered.

Wash the retardant off your skin as soon as possible to prevent irritation. Retardants are made from various chemicals, some stronger than others, which can cause irritation to the skin and eyes and be dangerous if ingested.

CAL FIRE and the U.S. Forest Service released a video several years ago. This video included dramatic footage of 9,000 pounds of fire retardant striking – and crushing – an SUV, underscoring the dangers of personnel working beneath aircraft. Imagine the harm from a low drop from a VLAT carrying 170,000 pounds of retardant – that’s the equivalent of the weight of six Type 3 engines falling out of the sky.


With fire season being year-round in California and many other states now, many fire departments and private air resource organizations are purchasing newer, sophisticated aerial firefighting equipment. Larger payloads, though more effective for firefighting, can be an increased threat to personnel on the ground.

Follow the above steps to stay safe on the Fireline – and work with pilots to ensure strong communication among teams. And identify whether your department has – or needs – a policy related to working around fixed-wing or rotary aircraft during wildfires. Now is the time to update, prepare and train!

Fire Chief Sam DiGiovanna is a 35 year fire service veteran. He started with Los Angeles County Fire Dept. served as Fire Chief with the Monrovia Fire Dept in Los Angeles County and now is Chief at the Verdugo Fire Academy in Glendale Ca.

AerialFire Staff
AerialFire Staff
AerialFire Magazine strives to provide you with breaking aerial firefighting industry news and information.

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