Firefighting from the air
July 1, 2011
FORT HUACHUCA, Ariz. -- Each year, air tanker pilots from across the country report to the Air Tanker Base adjacent to Libby Army Airfield here, to answer the call of the annual wildfire season in the Southwest.
These unsung heroes, the air tanker pilots, air attack pilots, officers and supervisors, assist the firefighters on the ground and play an important role in the way wildfires are contained, fought and extinguished.
When the Monument Fire broke out in the Huachuca Mountains June 12 many were already fighting both the Wallow Fire (now, the largest wildfire in Arizona history) and the Horseshoe 2 Fire.
Because thousands of structures were in harm's way, air tanker resources were diverted to the Sierra Vista area, dispatching as many as 10 of the nation's 17 air tankers to actively engage the Monument Fire.
The base has what it needs to support firefighting efforts several hundreds of miles away. Large bins of powdered fire retardant hold enough of the mix to fill one and a half planes.
The retardant is a combination of ammonium salts that char on contact with flame (and also fertilize the area, encouraging post-fire re-growth of vegetation) and a colorant that shows the pilots and firefighters where it lands, that is then mixed with water in large tanks located just off the flight line.
The active ingredients in the retardant do not evaporate, so they work well when fighting high-intensity fires and are usually applied ahead of the advancing fire by tanker pilots, boxing the fire in and preventing it from spreading further.
When a tanker is dispatched to a fire, a smaller fixed-wing aircraft called "air attack" will lead the tanker to the line of the fire and show the pilot where to drop the retardant.
"Basically, we just fly along and say 'start here,'" explained Kenneth Perry, an air tactical supervisor from the Bureau of Land Management.
With 2,500 pounds of retardant on board the trailing tanker and flying at 150 feet above the tallest object on the ground at speeds up to 130 knots, the process is a bit more complicated than that.
For example, wind and terrain play a large part in the pilot's ability to execute a precise drop.
Mountainous terrain and low-level flying are not the conditions most pilots are accustomed to or comfortable with, and at times, a pilot will leave the program right away because of it.
The training and experience involved in becoming an air tanker or air attack pilot takes a level of commitment that only a select few are willing to make and those that do stay learn to use these elements to their advantage.
"We have a little smoke generator on one of our engines and as the air attack officer crosses the start point where he wants the retardant to start, he will pop smoke where he wants [the tanker pilot] to push the button," Perry said. "The good thing about smoke is that not only does it mark the target area, but it drifts with the wind, so the tanker pilot can see that wind just hauling,sidestep over,judge it himself andadjustfor the windage."
On the toughest day of the fire, the winds were too strong to fly, but as soon as they died down in the evening, the pilots immediately took to the air.
In fact, one tanker flew every four or five minutes.
"It really worked out perfectly because as soon as one had dropped, you had another one ready, and nobody was ever holding and you were never waiting for another tanker," said Dave Dicky, Sierra Vista resident and contractor air tanker pilot for Aero Union Corporation. "It was really nice how well that worked out."
Those that do stay have the distinction of playing a dangerous, yet integral role in fighting fires from the air by creating the conditions