Editor’s note: This article was first published on FireRescue1.com.
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 tops on my list of fire service intrigues is air operations – one of 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 the pilots face unique stressors and dangers, but it is important to remember the hazards on the ground as well, particularly in the presence of firefighting aircraft dropping retardant (jell or foam), paracargo or water. News headlines capture the dangers (or mishaps) of such drops:
- Utah battalion chief’s death may have been linked to airplane retardant drop
- CAL FIRE air tanker pilot accidentally drops fire retardant in neighborhood
- Video: CAL FIRE demos low drop with S-2 aircraft
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 as a heavy rain, the danger to firefighters is reduced and effectiveness is increased.”
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.
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.” Read more in the DOI Interagency Aviation Safety Alert.
With this in mind, it should be no surprise that personnel can be injured by the impact of material dropped by aircraft. So, let us detail some of the safety tips related to retardant and water drops, courtesy of the National Wildfire Coordinating Group (NWCG) 6 Minutes for Safety (6MFS) program. Consider the following for all drops you are coordinating:
- Be aware of the location and flight patterns (final approach, drop zone, exit) of aircraft during drop operations. It is important that you can monitor air-to-ground radio traffic to know when and where aircraft will be working. Your strike team leader or division supervisor should monitor radio traffic as well. Understanding flight patterns and drop locations is important to your safety. Remember, rotor wash from helicopters can also spread fire with erratic wind caused by rotor blades.
- Ensure you have positive contact with the pilot before the drop. Drops can be extremely dangerous. It falls right in with the 10 Standard Firefighting Orders. If you do not have visual contact, you or your supervisor should have radio contact.
- Clear all persons, vehicles, and animals from the danger zone prior to the arrival of the aircraft. Water drops come with a great deal of force – a force can be strong enough to move vehicles, large boulders, or break trees.
Personnel should be cleared from the target area before the drop is conducted; however, if an individual is caught unaware in a drop zone, follow these 6MFS tips:
- Hold hand tools away from your body. The force of the water or retardant could impale hand-tools into your body.
- Lie face down with hardhat in place and head toward the oncoming aircraft. If you face in the direction the aircraft is heading, the force from the drop can easily take your helmet off your head. Additionally, the force of the drop could cause severe injury and/or death if hit in the face.
- Grasp something firm to prevent being carried or rolled about by dropped liquid. If you are not secured, you can easily be violently moved with injuries and/or death as a result.
- Do not run unless escape is guaranteed. Sometimes sheltering in place may be your best alternative.
- Get clear of dead snags and treetops. The force from drops can easily break tree limbs that become projectiles.
- Be aware of rolling debris below the drop site in steep terrain. Once the drop is performed, rocks, trees and equipment may be dislodged. Be aware of rolling objects coming your way!
Do not forget Fire Order #7: “Maintain prompt communications with your forces, your supervisor, and adjoining forces.” It is important to make aware of who is calling in the drops and want to let others know when calling in air resources. This is based on situational awareness, the foundation of our risk management. In the case something goes wrong, we know who to contact to adjust or stop until we can reevaluate and re-adjust the plan or go to an alternate.
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.
- The width of drops can vary from 95 to 135 feet.
- Firefighters should stay an additional 50 feet beyond these boundaries.
- Drop lengths can vary from 300 feet for smaller aircraft to 5,280 feet (1 mile) for VLATs.
- Avoid being in front or behind the drop zone line.
- Rising terrain, unexpected cross winds or aircraft malfunction can cause drops to be lower than intended.
- Firefighters must be aware of the risks of having aircraft assigned to their fire.
- Remember, “Heads Up” and “Clear Out.”
This video includes 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.
An Increased Threat
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!