Saturday, June 1, 2013
Fighting the Flames
Helicopters and the equipment they support are an invaluable component to aerial firefighting.
The use of helicopters to drop fire retardant, foam or water to suppress wildfires is an essential firefighting tool. Their speed, mobility and delivery capability make them very effective resources in support of firefighters on the ground. Small, medium and large helicopters can carry from 100 to 3,000 gallons of water, foam or retardant in either buckets slung beneath the aircraft, or in fixed-tanks.
The helicopter’s value is the capability to “shuttle water from nearby sources to the most critical areas quickly,” says Samuel Evans, former U.S. Army Colonel (Ret.) and senior research assistant at the applied research laboratory at Penn State University in University Park, Pa. “Although fixed-wing aircraft can deliver more water (or other retardant), they lack the more precise delivery capability of a helicopter. They also require a runway/airfield to reload. If a fire isn’t ‘conveniently located’ near an airfield, time between turns on a fixed-wing can be excessive.”
Helicopters “not only allow teams to reach the scene more quickly, but they also allow for increased precision during operations, as the helicopter’s speed and position can easily be adapted to the environment at hand,” notes Benoit Terral, aerial work/firefighting operational marketing manager for Eurocopter in Marignane, France.
In addition to delivering water and transporting people to/from fires, rotorcraft support various aerial work operations. “The helicopter is used in aerial reconnaissance for reporting fires, mapping fires, directing other aerial firefighting assets on fires, delivering equipment to remote areas, and providing hoisting, medevac and situation monitoring capabilities to ensure the safety of people involved in firefighting efforts,” says Shawn Bethel, division manager, Firefighting division for SEI Industries in Delta, BC.
The helicopter’s role in firefighting “has become increasingly important over the last 30 years and continues to evolve as technology has changed,” explains Mike Atwood, founder and president of Boise, Idaho-based Aviation Specialties Unlimited (ASU). “The Yellowstone Park Fire was a turning point in fighting fires with large helicopters. If it had not been for the two Type I helicopters making multiple water drops in very rapid succession, a great deal of the historic park buildings could have been lost.”
According to the U.S. Forest Service, helicopters were used to combat wildfires in California as early as 1947 and their usefulness at moving personnel rapidly around a fire was quickly recognized. Initially, helicopters were just used for tactical and logistical support for ground crews. In 1957, the Los Angeles County Fire Department experimentally used a Bell 47 to lay hoses using belly-mounted trays. In the mid-1950s, Jim Grady of Okanagan Helicopters reportedly developed the first water bucket with Henry Stevenson in a machine shop in Nelson, BC. This “Monsoon Bucket,” a converted 45-gallon drum with a trap door in the bottom actuated by the pilot in flight, became operational in 1962.
Rotorcraft also supply “a point attack capability and rapid turnaround that no other asset can provide,” says Jerry McCawley, test pilot and flight safety engineer at Lockheed Martin, Owego, N.Y. “Their ability to use water sources close to the fire such as ponds, streams or even swimming pools allows helicopters quick turns and more on-station time than fixed-wing assets, as well as the ability to drop very accurately on any hot spot that needs attention in a fire. This is particularly useful in fires in urban areas and was showcased with spectacular results in the fires that hit Sydney, Australia a few years ago. [They have] the speed and ability to get past fire lines and attack from any angle. Trucks often have to fall back due to fire encroachment – helicopters do not have this problem.”
What about the extra cost incurred by helicopters fighting fires? McCawley believes with all the costs associated with ground crews and the far larger numbers of personnel required to man the trucks the cost disadvantage is diminished or negated.
Lee Benson, helicopter consultant and retired senior pilot for the Los Angeles County Fire Department, stresses that helicopters do not put out fires, teams put out fires. “These teams include many facets but at a minimum they include command structure, logistics, communications, hand crews, caterpillars, fire engines and aircraft,” he says.
Benson, also a Public Service columnist for Rotor & Wing, explains that helicopters “act in a support role, and when used correctly they are providing direct support to the hand crews, dozers or infrequently engine companies. The purpose of the helicopter is to make the units above be more effective. Hand crews can only cut lines to a given flame height, the dozers can work greater flame length but there’s still a limit. When the flame height exceeds this value, the helicopter is there to knock the fire down to enable the fire line to be extended by either the crew or dozer. Engine companies are supported by the helicopter dropping around structures to lessen the flame height and intensity to enable the engine company the environment it needs to do its job of protecting a structure.”
Evans agrees that it takes a “team approach” to put out fires. “Unfortunately, like military operations; it takes ‘boots on the ground’ for the best chance for success,” he says. “Helicopters are a great capability, but a in a supporting role.”
Tanks and Buckets
Buckets and tanks are the main delivery devices to combat fires. The most popular of the buckets is the Bambi Bucket, introduced to the rotorcraft community by SEI Industries in 1982. It is “the first bucket that is collapsible, and able to be transported inside the helicopter and deployed within seconds to make drops on fires,” notes SEI’s Bethel. The Bambi Bucket is sold in more than 110 countries. It is lightweight, easy to use and relatively inexpensive to buy and maintain, according to Bethel. “There are some Bambi Buckets that arrive at SEI’s plant in Vancouver for repair that are 20 years old. SEI’s Bambi Bucket offers a range of models between 72 gallons to 2,600 gallons, allowing a Robinson R44 to a Boeing Chinook and everything in between to help ground personnel put out the fires.”
Tankers can be filled on the ground (by water tenders or truck-mounted systems) or water can be siphoned from lakes, rivers, reservoirs or a portable tank through a hanging snorkel. Pilots can program the tank dump doors from the cockpit to control the volume of water and number of drops. Popular firefighting helicopters include variants of the Bell 204 and the Erickson S-64 Aircrane helitanker, which features a sea snorkel for filling from a natural water source while in flight.
According to Mark Zimmerman, president and CEO of Simplex Aerospace of Portland, Ore., fixed tanks have several advantages over buckets including:
• Ability to fly at higher speeds
• Ability to fly over urban areas
• More accurate water drop
• FAA certified
• Fewer accidents due to bucket contact with rotors, trees or objects
There is an ongoing argument in terms of which device, bucket or tank, is best. “Both are used for the same application and both are successful,” says Keith Saylor, fire ops manager at Columbia Helicopters, also based near Portland, Ore. “The tank is the main difference between them. Many helicopters used for this purpose are standard category aircraft used for another aspect for flying years ago. If you have a helicopter that has a hook on it and it’s certified with a belly hook, it can safely be used for firefighting just by putting a long line and a bucket on it. When it comes to tanked aircraft, there are some hoops that must be jumped through to get the tanks approved, but once done, that aircraft can be used in a firefighting mode.”
Helitankers “normally have a larger capacity than the Bambi buckets, but weigh more and are more complex in installation and operation,” McCawley says. “Buckets are as simple as it gets.”
Mike Reightley, president of Bend, Ore.-based Kawak Aviation Technologies, believes that in this debate, the answer depends on the application. “There are conditions in which each device has its advantages and in the end, all are necessary tools in the helicopter firefighting arsenal,” he says. “Fixed tanks tend to be preferred over buckets in urban or urban interface areas such as Southern California in that they eliminate the risk of an inadvertent jettison over a populated area. They also mitigate the dangers to some degree of flying a long line implement in an area where hazards such as power lines are more prevalent.”
Innovative aerial firefighting companies are always looking for ways to improve their equipment. “The bucket has gone through major changes over the years with it becoming gated,” Saylor says. “You can adjust the gate or move the gate in an open-and-close position, so you don’t have to dump the complete bucket all at one time. It’s called a “torrentula” valve, called that for a torrential downpour. So you can split your load 10 times realistically. You can open it very slightly to drizzle water and make a long wind-up, or open it up and dump it all at once.”
Another important development is the powerfill. “Our buckets have four pumps in the bottom of them,” Saylor says. “If I can find 18 inches of water somewhere, I can set the bucket there, turn the pump on, and it will load the bucket to where it is overflowing. The advantage is with streams or creeks close to the fire, you couldn’t get enough water in them before.”
Many companies are looking beyond conventional drop materials. “I think the helicopter can be an extremely effective in the application of gel products and not necessarily limited to conventional tank or bucket drops,” says Reightley. “Kawak has utilized several of its current systems to effectively apply gel via a nozzle for accurate placement and swath control. Gel application equipment will be driven by the acceptance of gel; however, the science behind it and the effectiveness has been shown to be quite effective.”
New solutions are available to give aerial firefighters the forestry and environmental requirements indicating the type, location and volume of both fills and drops, in addition to providing operational load management and analysis. Mark Insley, P.E. and president of Latitude Technologies Corp. in Victoria, BC, says his IONode system provides data in both real-time and post-mission analysis. “This latter aspect allows stakeholders in all aspects of the aerial fire attack to get timely and appropriate information,” he continues.
Simplex’s latest product is the Aft Hook, a latch mechanism that connects the end of the hover pump to the aft belly of the aircraft during flight. Upon reaching a water source, the pilot can release the latch to deploy the pump and refill the tank. “The FAA prohibits the transport of passengers while the hover pump is deployed, but the Aft Hook provides operators the ability to transport firefighters to a fire without having to uninstall and reinstall the hover pump,” says Zimmerman. The Simplex tank model 304 for the medium Bell is the only tank with this transport category, he insists.
Night vision goggles (NVGs) are being used more frequently to effectively fight fires at nights. “At night, wind is typically down, temperatures are down and humidity is up,” notes Atwood. “This aids the helicopter in operating efficiencies. Night vision goggles can help spot hot spots and can see into the near-infrared range. When using them in conjunction with forward-looking infrared devices and laser pointers, operators have the ability to perform precise water drops on hot spots at night. This allows firefighting to occur 24 hours a day.” With these important innovations and their many aerial advantages, helicopters will be successfully supporting firefighting efforts for many years to come.
California on Fire: May 2013
As this article was being written in May 2013, California was suffering the effects of yet another of its infamous Golden State fires. According to the California Department of Forestry and Fire Protection, in the town of Camarillo, south of the 101 Freeway, approximately 25,000 acres have been destroyed, but no deaths have been reported.
“We are a little ahead of the fire season for California, but California is known to burn at any time,” says Keith Saylor, fire ops manager at Columbia Helicopters. “We currently have one of our Columbia Model 234 Chinook helicopters working under an Exclusive Use (EU) contract with the Forest Service. The Forest Service has been using it on fires in Northern California so far this season.”
Lee Benson, helicopter consultant, Rotor & Wing columnist and retired senior pilot for the Los Angeles County Fire Department, says: “I can see the fires from my house.” Benson attributes part of the fire to California’s dry climate. “The wind was blowing 50 knots; humidity is down in the four to six percent range,” he notes. “Big birds like crows, hawks and owls are almost perfect aviators, but not quite. Sometimes in the attempt to land on power lines, they will get on both leads (the hot and cold) and this fries the bird. Then the bird falls down into the brush and a fire starts.”
Although the cause of the fire remains under investigation, officials said that they had ruled out arson and instead believed the blaze was started by a small “undetermined roadside ignition of grass/debris.”