Hot Shots

Pilots fight fires from the air

October 1, 2007

Dawn breaks near Santa Barbara, California. A thick, gray-brown haze rising to 6,000 feet veils the San Rafael Mountains to the northeast. Smoke settles into the valleys and extends 40 miles south, up to the edge of the San Gabriel Mountains that shelter the Los Angeles basin. It crests the long ridgeline and drifts east over the San Joaquin Valley to Bakersfield. Beneath the haze, a quarter-mile wall of 30-foot flame licks the dry chaparral as it steadily marches up the steep ravines and rocky terrain.

Twenty miles north, pilot Chris Holm and co-pilot Andy Harcombe are going through their final checklists before takeoff from Santa Maria Municipal Airport. Their four arms wave and interweave in a carefully choreographed routine of flipping switches and pulling levers in their Lockheed P2V, a Cold War-era maritime patrol airplane converted to air tanker duty for firefighting. The airplane's two 18-cylinder, supercharged Curtiss Wright radial engines rumble like a gang of Harleys, and as the airplane prepares to take off, the whine of two Pratt & Whitney J34 boost jets cuts in. The airplane — with its 2,500-gallon load of fire retardant — begins rolling down the runway. The half-century-old relic shakes and rattles like an ancient school bus as it lifts into the air. By the time it has passed the airport boundary, the lumbering aircraft has barely reached 500 feet agl. At around 700 feet agl, Holm gently puts the airplane into a shallow bank and turns it toward the rising column of smoke.

Flying tankers

Since aircraft were first pressed into firefighting service in the 1950s, the job of flying air tankers in wildfire operations hasn't changed much. The airplanes still are mostly former military aircraft converted to air tanker use, the tactics are largely adapted from the military, and even the jargon retains a militaristic flavor. "Air attack" airplanes circle overhead, helping direct air traffic and coordinate strategy, while "bird dog" or spotter airplanes help lead tanker aircraft to the "target." As in a low-level bombing run, tanker pilots fly heavily laden aircraft near ground level over frequently rugged terrain in difficult, unpredictable conditions.

Although they are just one component in a multifaceted system that includes helicopters; hot shot crews on the ground; heavy equipment for cutting fire lines; and smoke jumpers, air tankers offer the fastest, most potent, and most cost-effective method with which to suppress new wildfires or slow the advance of growing ones.

Flying air tankers is, like bush flying, stunt flying, or ag flying, the art of taking something inherently dangerous and, through careful planning and repetition, making it relatively safe. It begins before each fire season, when veteran tanker pilots go through a course of recurrent training given by both the FAA and the USDA Forest Service. This course is supplemented by simulator training in procedures and cockpit resource management.

The pilots themselves are an eclectic bunch. Some are former military pilots. Others, like Holm, chief pilot at Neptune Aviation Services in Missoula, Montana, are career firefighters or forestry professionals. A few came to tanker flying as a way to break into commercial aviation or as an alternative to other flying jobs. Many fly tankers part time, taking time off from other jobs either to make a little extra money or simply for the challenge.

The action begins

When a fire is spotted, either through the 911 system, by fire-spotters on the ground, or in the air (fire towers are increasingly rare), an escalating system of action kicks into gear. After its location is established, the fire is evaluated by the topography of the area; the type of vegetation ("fuel" in the language of firefighters); weather conditions; accessibility; and the potential threat to life, property, or natural resources. During fire season, the National Oceanographic and Atmospheric Administration puts out a daily fire weather report, detailing the conditions and forecasts relevant to fire hazards. This report includes winds at 20 feet, relative humidity, and chance of precipitation, all of which help predict a fire's behavior.

The first goal is to extinguish the blaze quickly, as both costs and the risk to firefighters are reduced when fires are put out on initial attack. But after a fire spreads, the job turns from one of suppression to one of containment and management. Additional personnel and equipment are summoned, first through the local coordinating agency, then if necessary to one of 11 regional centers around the country, then through the National Interagency Fire Center, which can marshal resources from around the country, the military, or even other countries. Occupying a complex of buildings at a corner of the Boise Municipal Airport, NIFC employs some 500 people during the fire season. Its control center looks a bit like NORAD, with computer consoles; phone banks; and large screens that project the computerized flight-following system of the various tankers, helicopters, and surveillance and command aircraft in use at the time. Up to 50 people work 12-hour shifts when things are busy.

This fire, designated "Zaca," began from an errant spark during a metal grinding operation. As the blaze quickly burned through the dry grass and oak woodlands, it spread up the steep hillside and out of control. What started as a county operation expanded to include state, Forest Service, and Bureau of Land Management resources. By the end of the week, the fire had consumed more than 13,000 acres and involved more than 2,000 firefighters on the ground, along with 10 helicopters and seven air tankers, at a cost of more than $1 million a day.

Fire season

Fire season typically runs from May to September, moving from the Southeast and East Coast in the early spring, to the Southwest and Rocky Mountains in the late spring and early summer, to the Pacific Northwest and California in late summer and early fall. But a 15-year cycle of drought in the West and the growing encroachment of urban areas into wildlands have increased the length of the season and the severity of fires. The past three years have shown record totals for acreage burned in the United States — nearly 9.9 million acres in 2006. The Forest Service spent $1.5 billion fighting fires in 2006, nearly half of its annual budget. Of that, air operations soaked up nearly a third.

Yet, the Forest Service today has fewer than half the 33 heavy air tankers it did in 2004, following a series of in-flight breakups that prompted the agency to cancel all its air tanker contracts pending a review of the fleet's airworthiness. At the time, the fleet averaged 48 years old, with some airplanes as old as 60 years. In response, the Forest Service enacted strict guidelines regarding maintenance that, among other things, required air tanker contractors to establish and monitor the "operational service life" of the airplanes, something not even considered or required by the FAA when any of the airplanes were built. Neptune and Aero Union of Chico, California, which operates eight four-engine Lockheed P-3 Orions for the Forest Service, together with Lockheed Martin, scrambled to develop procedures to comply with the new rules. The rest of the fleet, although legally airworthy by FAA standards, was forced into retirement.

To make up for the loss of heavy tankers, the Forest Service has used more helicopters and added 20 single-engine air tankers, or SEATs, such as the Ag Cat, which can drop 500 to 800 gallons of retardant or water. A number of states, most notably California, operate their own fleets. The California Department of Forestry and Fire Protection owns 23 Grumman S-2Ts, former carrier-based submarine trackers retrofitted with two Garrett TPE331-14GR engines. It also operates 11 helicopters and 14 fire-spotting air attack airplanes, deploying them from 13 air attack bases and 9 helitac bases. The state has also deployed a DC-10 airliner converted to a tanker. The jumbo, designated Tanker 910, can drop more than 12,000 gallons of retardant.

The loss of heavy tankers has forced the remaining Forest Service tankers to cover a wider area. Before 2004, Holm could reliably count on being based in one place for one or two weeks at a time. Today, he's likely to take off with a load of retardant destined for one place, only to be diverted to another destination where it is more desperately needed, then be diverted yet again to a different location. Each morning, Holm checks out of his motel, never knowing where he'll be sleeping that night.

This uncertainty also complicates the job of the mechanics, who follow the airplanes around in trucks full of tools and spare parts. Jeremy Robbins, mechanic for Neptune's Tanker 9, says he spent nearly three weeks chasing the airplane around the country. In all, he saw the airplane for maybe two hours during that time, and by the time he finally caught up to it, he had to spend two days making up the maintenance backlog.

Weather

The Zaca fire has been particularly difficult to fight, not only because of the vegetation native to Southern California, but also because of the region's weather patterns. Because air tends to move toward heat and its associated lower pressure, the prevailing winds during the daytime tend to be onshore. Since water holds heat longer than air, the evening winds reverse direction and move toward the ocean, making the job of fighting the fire particularly difficult.

But large fires also generate their own weather. For tanker pilots, this means having to contend not only with reduced visibility because of smoke, but also with winds that can sometimes reach hurricane force, severe updrafts or downdrafts, turbulence, fire-induced thunderstorms, and swirling funnel clouds of hot ash and embers called fire devils. Pilots won't intentionally fly through such conditions, but fire behavior changes so quickly that it makes such phenomena difficult, if not impossible, to predict. "I've been in conditions in which debris, large tree branches, are flying through the air," Holm says.

During an active operation, a firefighting air base takes on the character of the deck of an aircraft carrier. To manage the activity, a ramp manager coordinates ground activity, overseeing a couple of parking tenders who guide the tankers and other aircraft into position, and three or four loaders manning the heavy-duty hoses through which retardant is pumped into the airplanes. Many of the airplanes can be "hot loaded" — with engines running — to reduce turnaround time and thus increase the number of drops.

FireTrol or Phos-Chek retardant comes in either a powdered or liquid concentrate form. When mixed with water it creates a heavy, bright red slurry that coats the vegetation and slows ignition. Water, explains Craig French, air base manager at the Porterville, California, air base, tends to atomize when dropped from 150 feet by an airplane traveling at nearly 175 knots per hour. This means much of it either evaporates before hitting the ground or gets blown off target. Retardant, in addition to being heavier and more viscous, has the added advantage of acting as a fertilizer for plant regrowth after the fire. Across the West, the marks of old retardant drops can be seen from the air as bright green lines of fresh growth amid fires' blackened scars. The Forest Service uses an average of 15 million gallons of retardant a year — as much as 40 million gallons during a busy fire season — at a cost of about $1 per gallon. Retardant alone cannot extinguish a fire, but it buys time until ground crews arrive on the scene.

Releasing the load

Tanker 9 nears the Temporary Flight Restriction, a 20-mile cylinder of restricted airspace over the fire put in place at the request of the Forest Service (one of dozens of TFRs dotting the western United States this day). The thickening smoke steadily decreases the visibility from the announced 10-mile visibility at Santa Maria airport to five miles at the edge of the TFR, to at best three miles over a long ridge known as the Hurricane Deck, where Holm will be dropping his load.

As he approaches the fire, Holm checks in with Mark Nunez, Forest Service division chief of air operations at Santa Maria and the man leading the air attack. Sitting in the right seat of a Twin Commander 690B orbiting 2,000 feet above the fire, Nunez works five separate radios as he directs air traffic inside the control zone above the fire, coordinating ground crews and air tankers, and communicating with managers on the ground and back at the air base. At large fires, the airspace can resemble that of a busy airport, with 15 to 20 aircraft operating within a one-mile circle of airspace. In addition to a TFR to keep out sightseers, an air traffic control zone is established five miles around the fire, to a height of 3,000 feet agl. Aircraft entering the control zone are stacked according to mission and aircraft type.

In the back of the Aero Commander, Rick Wilborn uses a joystick and a laptop computer to control an infrared camera mounted in a turret on the belly of the aircraft. This setup enables him to see through the smoke. His job is to mark the perimeter of the fire, as well as the heat and direction of the burn, and catch any hot spots that pop up. This information, in addition to helping Nunez develop strategy, is recorded to create detailed maps of the fire's evolution and movement.

Smoke and flames make it difficult to describe and direct tankers to the target, so lead airplanes, or bird dogs, are used to pinpoint the target, figure out the approach and escape route, and guide the tankers to the drop. "It's like an approach to an airport," explains Cliff Naveaux, who pilots a BLM-operated Beechcraft King Air on lead. "You keep it square, just like a pattern, preferably with the target on the left so you can keep it in sight. In fact, when we call our position we use the same terminology: 'I'm on upwind, downwind, base, final.'"

As Tanker 9 approaches the target area, Holm and Naveaux use their onboard traffic alert and collision avoidance system (TCAS) to help set up an intercept between the two airplanes. Flying toward each other at a right angle, Noveaux turns sharply at about a half-mile away. The wingover enables Holm to pick up the airplane visually and follow in trail, keeping about a quarter mile behind and to the outside of Naveaux's airplane. Holm slows to approach speed — around 140 knots — dropping his flaps but maintaining high power in case he needs to abort. "You're always keeping your escape route in mind, and to be ready to release the load if you need to," Holm says.

If needed, Naveaux can release a smoke trail on final approach to the target so Holm can gauge the effect of the wind. As Noveaux passes over the target, he makes a sharp, climbing turn to mark the spot. At about 150 feet above the ground, just as the target slides under the nose, Holm presses a button on his control yoke to release the load. Six synchronized doors open in sequence, sending 2,500 gallons of retardant hurtling to the ground, painting a bright red line 30 feet wide and more than a quarter mile long over the dense undergrowth.

Holm turns back toward base, where the airplane will take on more retardant and then head back for another drop. Holm and the other tanker pilots will repeat the process several times before calling it a day. Forest Service regulations limit pilots to eight hours of flying per day, six days a week, but when combined with planning, pre-flight, and maintenance issues, they can be very long days, Holm says.

Holm knows that firefighting is not an exact science. Often, it is a game of numbers, but in the case of the Zaca fire the numbers are against them. "Once a fire reaches a certain size," Holm says, "it's going to do what it's going to do."

After seven weeks, the Zaca blaze had burned across 214,725 acres, cost nearly $85 million, and injured 30 people. The fire was declared 100 percent contained on September 2, 2007, by then having burned 240,207 acres. It cost more than $119 million.

Tom LeCompte is an editor and journalist living in western Massachusetts. He is a private pilot with more than 850 hours.