Last November’s wildland fires across the state of California killed dozens of residents, burned thousands of homes and structures, and left tens of thousands of people displaced. Into this horror, California threw the full weight of its firefighting assets, including three S-70 Firehawk® helicopters that carry 1,000 gallons (3,785 liters) of water in a specially designed tank attached to the belly of the aircraft.
Additionally, UH-60M Black Hawk helicopters operated by the National Guard, a reserve military force of the United States, as well as commercial operators with UH-60A and UH-60L models, also fought the fires with water buckets suspended beneath the aircraft.
Aerial firefighting with helicopters has advanced significantly in the first two decades of this century because of the pioneering efforts by the County of Los Angeles Fire Department.
Following devastating fires in the mid-1990s, County officials realized they needed a military helicopter that could attack a fire with the rigor and reliability of an aircraft designed for the battlefield.
That is because fighting fires from a helicopter is much like bringing troops into a war zone, and then assisting and protecting those troops from the air.
In its firefighting role, the Firehawk helicopter can insert up to 12 firefighters at the edge of the fire line or where needed. These firefighters are equipped with chain saws and other hand tools to cut and smother the burning brush, and so contain the fire.
While this ground operation is underway, the Firehawk helicopter will fly to the nearest water source – whether a swimming pool, a lake or river, or a portable tank placed nearby by the fire department. With its snorkel extending below the aircraft, the Firehawk can hover above the water source, and pump into its belly tank a total of four tons of water in just 60 seconds.
The aircraft then returns at high speed – usually 125 knots – to the fire. The ability to fly low, close to canyon walls or buildings, means that the water is dropped with great precision and force. The effect is to reduce the flames so that the firefighters on the ground can advance.
Of course, repeatedly acquiring, carrying and dropping four tons of water onto a fire – sometimes up to one hundred times throughout the course of a day – places huge stresses on the Firehawk airframe. But a military design can accommodate this abuse without injury.
The Woolsey Fire
The Woolsey Fire in Southern California near Los Angeles, started Nov. 8, 2018, and nine days later had destroyed almost 100,000 acres and more than 6oo buildings.
Three Firehawk helicopters flown by multiple Air Operations crews employed by the County of Los Angeles Fire Department “dropped water” for 40 of the first 48 hours of the fight, accumulating a total 110 flight hours during the first four days. Maintainers worked round the clock too, ensuring maximum flight availability.
Senior Pilot Mike Sagely called the conditions “dynamic,” flying in steady 40-knot Santa Ana winds, often at night. Smoke in the cockpit stung his eyes while he maintained a hover one meter over swimming pools so as to siphon water into the belly tank. Operating in conjunction with ground crews, he saved as many homes as he could.
“We attacked the fires very aggressively,” said Sagely, “because the Firehawks are capable of doing that. These aircraft like it better when they’re flying all the time. They want to run. They are like a thoroughbred.”
A new generation Firehawk
A Firehawk is born a Black Hawk utility helicopter, nearly identical to the aircraft operated by 30 militaries around the world.
To become an aerial firefighting vehicle, the aircraft is equipped with the water tank, as well as an extended landing gear (to give the tank added clearance from the ground), a retractable snorkel, and a rescue hoist.
Over the next five years, Sikorsky is expected to deliver more than 12 third-generation Black Hawk aircraft to firefighting agencies in California, including the California Department of Forestry and Fire Protection (CAL FIRE), which is replacing the state’s aging UH-1H fleet.
In this endeavor, Sikorsky is teamed with United Rotorcraft, a division of Air Methods in Texas, which is modifying each aircraft to the Firehawk configuration.
CAL FIRE and others will acquire (starting in 2019) a digital aircraft with modern technologies than will make the task of aerial firefighting both safer and more effective.
- The new generation S-70 Black Hawk aircraft’s advanced digital cockpit takes on many of the aircraft’s flight functions, allowing the Firehawk pilot to pre-program and manage the mission while adjusting flight parameters, such as speed, precision hover, heading and altitude, as needed.
- A four axis coupled flight control system enables the pilot to hold an exact hover in high wind rescues or when hoisting a victim from a canyon ledge.
- Improved power from the 701D engines, and wider chord rotor blades, provide greater lift and performance so that pilots carrying water at 10,000-ft (3,048 m) altitude in hot conditions are not living on the edge of their power margin.
- Night vision googles and night-vision-capable avionics allow night fire-fighting operations.
- A digital moving map shows the pilot the aircraft’s precise location and destination at all times.
- Among its standard safety features, the S-70 aircraft includes a terrain and obstacle avoidance system that alerts aircrew to the proximity of potential ground hazards.
- An Integrated Vehicle Health Management System, and a flight data recorder, monitor the aircraft’s operational health.
- Active vibration control makes for a smoother flight and reduces occupant fatigue.
- Excellent tail rotor authority ensures high maneuverability and control responsiveness.
- A high speed machined airframe ensures greater strength and corrosion resistance, improving occupant safety and fatigue life.
- The water drop pattern from the belly tank can be adjusted in quantity or concentration (¼ or ½ or ¾ tank, or full salvo drop) to avoid injury to ground crews, and to suit the size of the fire.
- The belly tank is designed with enough pressure to penetrate through the dense underbrush commonly found across California to extinguish flames at the source.
- Sikorsky also has developed an aircrew and maintainer management system and training program to help maintainers record and manage fleet operations.
These technologies — now inherent in the third generation S-70 Black Hawk that Sikorsky is building — also improve Firehawk reliability and maintainability. The result is reduced direct operating cost and increased mission availability for firefighting.
Multi-role versatility
The three second-generation Firehawk helicopters currently operated by the County of Los Angeles Fire Department have proved their worth, not just for wildland fire suppression, but also as a general rescue platform,
In fact, firefighting makes up just 15 percent of the county’s mission spectrum. Because their mission set is so broad, the county required an aircraft that could switch roles at a moment’s notice — even while airborne.
Seats in the cabin can be folded into the ceiling. Rescue medics can bolt equipment to hard points on the Firehawk’s cabin floor. The aircraft can hoist patients into the cabin for treatment and transport to a nearby hospital. The belly tank can be dropped quickly as well (in under 45 minutes), allowing use of the 9,000-pound (4,082 kg) cargo hook.
During the recent Woolsey Fire, the County of Los Angeles flew a new-generation S-70 Black Hawk helicopter (prior to modification as a Firehawk) as a command and control platform. Aboard, a battalion chief coordinated movements of ground firefighting units and other aircraft.
Los Angeles has also used its Firehawks to rescue animals; in more than one case by lifting via its 9,000-lb cargo hook a stranded horse from a canyon.
In 2015, a Firehawk performed a rescue and firefighting mission on the same flight. A substantial brush fire erupted after a pick-up truck veered off a freeway, tumbled down an embankment, and burst into flames. Lowered by rescue hoist, the crewman located and recovered the injured driver, who had crawled up a water drain pipe to escape the flames. After extinguishing the flames, the aircrew flew the victim to a nearby hospital, where the driver made a full recovery.
Final word
The County of Los Angeles Fire Department leads the world in aerial firefighting from helicopters.
Using the Firehawk platform, the department has pioneered how to suffocate wildfires in their nascent stage when a fire is most vulnerable, and while working in close coordination with other aircraft and firefighting crews on the ground.
Of course, once a fire becomes a conflagration across many kilometers of terrain, as the recent wildland fires became in California, the Firehawk helicopter still serves a vital role saving individual structures from destruction.
By its many achievements protecting lives and property with the Firehawk helicopter, the County of Los Angeles Fire Department has sealed its reputation for life-saving innovation in the modern age.
All of us at Sikorsky and Lockheed Martin are awed by what the County imagined was possible in its quest to save lives and property with a firefighting helicopter.
And we remain humbled by the sheer intensity of willpower that it takes firefighters to perform their dangerous mission — surely an example of the highest ideal of public service.
For more information, go to www.lockheedmartin.com/firehawk
