21 August 2015

Fire-fighting pilots


Stephen Dowling has a BBC article about aerial fire-fighting in the West:
The summer of 2015 has been a cruel one for the Pacific states of the US. California, for instance, has sweltered in record temperatures, as a crippling drought has entered its fourth consecutive year. It’s a drought that is expected to cost the state some three billion dollars and cause the loss of at least ten thousand jobs. But there are other effects too, far more physical, elemental, and frightening.
In the past few weeks, hundreds of firefighters have battled blazes in the Jerusalem Valley in northern California. In states further up the coast, such as Oregon and Washington, more blazes have erupted, fueled by bone-dry brush and fanned by hot summer winds. The California drought has turned to tinder much of the state’s bush and forest. Nearly half of the state is forested. And when this dry forest catches alight– either from summer thunderstorm lightning strikes, accident, or arson– the devastation can be immense.
It’s something Rick Hatton knows only too well. In the last few weeks, Hatton’s company 10 Tanker has been in the thick of it, fighting fires in California and Washington state. His company uses converted DC-10 jets to douse the forest with fire retardant: a mixture of water and a type of fertilizer that soaks into the wood and makes it less likely to burn. To be effective, the pilots must fly the large aircraft only two hundred feet above the treetops. “The process is very visual and requires vigilance and skill,” he explains.
All over the world, during summer, pilots like Hatton must make these spectacularly low flights to help halt the flames and, when the retardant is dumped, it can be a spectacular sight – as the photo above shows. What does it take to fight fires from the air?
The DC-10s often don’t drop retardant on the fire itself; they douse areas in front of an advancing fire, starving it of fuel and making it easier for ground crews to tackle. They also don’t work alone. They are supported by fire-fighting teams on the ground, and smaller ‘spotter’ aircraft which fly ahead of the tankers and direct them.
“We have now flown DC-10 tankers on over sixteen hundred fire flights on more than three hundred fires,” Hatton says. “Each flight is a little different, but all use a lead plane which directs our three-person crew as to where and at what concentration the retardant is to be dropped. We can segment the drop or deliver it in one continuous line up to nearly a mile long."
Hatton says flying the DC-10 so close to the ground (DC-10s usually fly so low only when they’re approaching an airport) is not necessarily dangerous; the tankers carry a much lighter fuel load than they would have as airliners, so they’re not as heavy and therefore able to maneuver more quickly. But this is anything but a routine activity; in 2007, the company’s first DC-10, Tanker 910, encountered turbulence and dropped some two hundred feet lower than anticipated. The plane’s wing clipped the top of the trees before the crew could pull the aircraft back to a safe height.
Hatton says the workload can be intense during a busy fire season. “We have flown as many as nine times in one day with one crew. The fires that grow to mega status have had as many as fifty of our flights to contain them, but the average is nearer five.” Pilots are restricted to no more than fourteen hours on duty, even during the biggest fires, and must have at least two days off every fourteen days.
Hatton says the DC-10’s ability has changed fire-fighting tactics, leading to a technique called ‘overkill’: hitting small fires as hard as possible before they grow into bigger, more unpredictable conflagrations. “This tactic, called ‘first strike’, is being adopted by many agencies to help mitigate what is likely to be a fire-prone future in many geographical regions of the world.”
The aircraft’s large capacity makes this possible. “We developed the DC-10 to bring more quantity of suppressant to the fire in one load than any other tanker currently in use,” Hatton says. “The DC-10 is a real game changer.”
One of Hatton’s DC-10s has flown out to Australia to be used during the fire season there. And the DC-10s are no longer the biggest fire-fighters in service. In 2009, a converted Boeing 747 Jumbo Jet operated by Evergreen International has also been used to fight fires. The giant jet can carry twenty thousand gallons of retardant or water for four thousand miles, and is the biggest fire-fighting aircraft in the world. There are plans to convert an even bigger, stretched version of the 747 into a tanker as well.
Smothering flames with giant airliners is a big leap forward from aerial fire-fighting’s humble roots. According to the Forest Service, the first recorded fire-fighting flight was in 1930, using a beer keg filled with water, dropped from a Ford Trimotor plane. The technique began in earnest in the 1940s. Before then, rural firefighters often had to watch blazes burn through brush and forest from a distance, intervening only when fires approached closer to human settlements. After World War Two, there was a glut of military aircraft suddenly surplus to peacetime requirements and a huge number of demobilized pilots able to fly them.
But, as the years passed, the techniques improved, and the amount of water the planes could shower over fires increased. Old bomber aircraft, such as the four-engined Boeing B-17 or the carrier-based Grumman TBM Avenger used in World War Two were modified, their internal bays converted to carry water instead of weapons.
The development of different techniques to tackle different kinds of fires soon called for different types of aircraft. Smaller blazes can often be put out by helicopters carrying water buckets filled in a nearby lake and suspended on a cable beneath. Some helicopters can carry more than two thousand gallons of water. And a Canadian-built plane, the Canadair CL-415, performs a similar feat, scooping up water from lakes, and dumping it on fires.
The US is not the only place where fire-fighting planes are deployed. Wildfires are also a problem in Canada. More than a third of the country’s landmass, some three million square kilometers, is forested. The dry, continental summers can see little rain and temperatures over 40 degrees Centigrade; ideal conditions to give birth to devastating fires.
“Should a lightning storm come through an area with dry conditions, multiple wildfires can start in a very short time that can keep us busy for days or even weeks,” says Ray Horton, of the British Columbia-based Conair, who has been flying on anti-fire operations since 1981.
Aircraft are only allowed to fly missions during daylight hours. An average day starts around 9 am, with crew undergoing briefings while their aircraft are fueled and filled with fire-retardant chemicals. Then they wait and wait and wait for news of fires.
“As with most firefighters we tend to go through long periods of boredom punctuated with brief periods of intense activity,” says Dennis Chrystian, another Canadian fire-fighting pilot who flies with Air Spray, based in Alberta.
“Our level of preparedness depends on the level of fire hazard, and varies from having one hour to get in the air to a state where we are ready for immediate dispatch. The aircraft operated by Air Spray are all retardant-carrying tankers. We do not attack the flame directly as a ‘bucket brigade’ would, but are trying to fire-proof areas ahead of or along the flanks of a fire.”
The retardants used by fire-fighters were once more damaging to the forest: in the early days, sodium calcium borate was mixed with water, but this chemical sterilized the ground. Now they contain fertiliser. “It is usually colored red or lately, bright pink, in order for flight crews to see it clearly in the trees and allow for 'tagging on' and extending an existing retardant line,” says Chrystian. “The color is designed to fade over time, and the fertilizer properties actually promote growth and rejuvenation after a fire is extinguished.”
However, in order to protect wildlife and avoid contaminating water, pilots must carefully avoid dumping the retardant near rivers and lakes, or in areas known to have endangered species. When the tankers reach the fires, they follow the directions of the spotting planes. “We do our best to remain clear of the thick smoke column rising from a fire and thereby avoid most turbulence associated with the fire itself,” says Horton. “However, flying low level in the summer months is typically always somewhat turbulent from rising air near the Earth's surface. Another factor that is often the cause of large fires is wind. Strong winds that may fan a fire always provide a challenge for aerial firefighting due to terrain-induced turbulence, wind-driven smoke, and the retardant drifting too. This can also make it difficult to control airspeed and altitude.”
It can get hairy at times. This year, a fire blew up one around one of the company’s pilots. “In the few seconds it took to get out of the heat and turbulence two of his engines failed,” he recalls. The tanker managed to limp back to base on its two remaining engines.
“There is some inherent danger in our line of work, however we all work very hard at reducing the risk,” Chrystian continues. “One of the biggest risks we face is complacency. If it’s your job to fly a hundred-thousand-pound tanker down to a hundred and fifty above the ground and fly it as slow as possible every day, it’s easy to start to think of that as routine. It is anything but routine."
Chrystian says the worst fire he has seen was one he fought was at Slave Lake in Alberta, Canada in 2011.  “Relatively speaking, the fire was not large but managed to get into town destroying thirty percent of the town and doing nearly a million Canadian dollars in damage. It is considered one of the worst natural disasters in Canadian history.
“The fire was driven by winds that exceeded a hundred kilometers an hour, and we were powerless to stop it. We continued to attempt to stop or slow the fire right up until it got into town. The only positive effect we had on that day may have been keeping the road open so the residents could get out of town. No lives were lost to the fire.”
Both pilots stress that their aircraft are just a part of the puzzle when it comes to fighting fires. “It is the men and women with boots on the ground (with cooperation from nature) that put fires out, we only operate in support of the ground crews, says Chrystian. “We act to slow or hold fires so that the ground crews can get them under control. The really large fires require rain or winter to be put out.”
And they never forget the power of what they are up against. Horton remembers the moment he saw his first fire. “It’s frightening and awe-inspiring at the same time. It is incredible to see what the power of Mother Nature can do when the right conditions exist.”
Chrystian agrees. “The first time I saw a large fire from the air, knowing we were going to attempt fighting it, I was totally demoralized. A large fire can make you feel very small.”
Rico says it's another job he's happy not to have, but glad they do...

No comments:

Post a Comment

No more Anonymous comments, sorry.