13-17 Sept 2010

8-10 Sept 2010

This year the wildfire season in Colorado has been a relatively quiet one but in the week beginning 6th September it changed in an instant with a pair of back-to-back fires needing aerial support.

The Fourmile Fire was first noted at 10:00 on Monday 6th September in the Fourmile Canyon area, which is northwest of Boulder in Colorado. Fire crews reported crowns of up to 200 feet, and with winds of up to 45 mph, the fire spread very rapidly and necessitated the evacuation of 1,000 homes. On the first day the area covered by the fire was approximately 3,500 acres and was zero percent contained.

When the fire is first reported, this will be the time that the air assets are assessed and the nearest base is put onto standby. In this case the base was Jeffco Tanker Base located at the northwest corner of Rocky Mountain Metro Airport in Broomfield in Colorado. The base is manned with a Manager on a full-time basis all year round but an Assistant Manager is only on duty during the fire season. Other staff are pulled from various Federal Agencies including, but not limited to, the likes of Fish and Wildlife, Forest and Park, all of whom are qualified to fill the various duties at the tanker base.

When the call comes in that the tankers will be dispatched to the base, staff are released from their normal day jobs and report for duty at the tanker base. Some staff are local but many are from out of State and either drive or fly in to report. By the evening of the first day of the Fourmile incident two tankers had already arrived at Jeffco ready to respond, these being an Aero Union P-3 Orion and a Neptune Aviation P-2 Neptune.

As well as the more familiar tankers a host of other aircraft are involved in the complicated dance that is fire suppression. The Air Attack aircraft flies near the top of the Temporary Flight Restriction (TFR) airspace, this being created by the Federal Aviation Authority (FAA) to give the airborne element of the fire flight protection from aircraft not controlled by Air Attack. This lone aircraft controls the airspace and supervises all traffic from the lead aircraft through to news helicopters that may be just outside the TFR.

The Lead Aircraft are given direction on where the ground based fire-fighters want to establish lines of retardant to help them fight the fire. The Lead Aircraft will then perform dry runs to establish entry and exit points, flying their specific tanker profiles to ensure safe operations. Sometimes they may make a dry run with a tanker following to better explain where the drop needs to take place. When the call to "go live" is made the tanker will arm its drop system and follow the lead plane into the drop-zone and either drop all or part of its load with the ground crews determining the amount required.

Talking to Dave Stickler, a lead aircraft captain of ten years, he said "It's not just the different flight characteristics of each type of aircraft used in the fire-fight that we have to take in to account, but each individual captain flying that airplane. One may like a tight turn into the drop-zone and another may prefer a long lead-in. Some like to fly straight out if possible while others want to turn immediately away from the drop. We know how each captain likes to fly and try to accommodate them and keep them in their comfort zone if at all possible." Dave used to fly with the airlines but he is obviously more content in his current role. It's amazing to listen to guys like him talking to the tanker crews during the fight. It's so relaxed and professional you could almost think they were sitting at home with radio, instead of dealing with the very real situation that they find themselves in. The Air Attack and Lead Aircraft were King Airs and a Cessna 340 while Aero Commander N93AA, based at nearby Front Range Airport, was used only in the Air Attack role.

Like the tanker crews, Air Attack and Lead crews are nomads for the fire season and can be called to any US State that requires their help. With only 18 tankers outside of California to cover the whole of the United States these deployable resources are often stretched, and assessing where people's lives and structures are most at risk comes into play when the decision is made as to where to send the assets. The days of 40 plus tankers in the inventory are sadly a thing of the past after the FAA grounded the C-130 Hercules and PB4Y Privateer airframes from fighting fires; this after a couple of catastrophic wing failures in Colorado forced operators like Hawkins and Powers out of business. The fleet is stretched, but both Neptune Aviation and Minden are developing new airframes based around the BAe 146.

Another interesting aircraft is the Forest Service Beech King Air 200 N149Z. It has a thermal image infrared camera housed in the belly and maps the area, picking out hot-spots for investigation the next day. It generally flies at night and, due to the nature of their work in the dark, they are known to the other flight personnel as the Vampire Crew.

The retardant used to combat the fires is fertilizer based, mostly made up of diammonium phosphate mixed with water at a ratio of 5.5 parts water to one part retardant. The red colour is iron oxide which is used as a dye so that the lines can be easily seen and also included is guar gum, which is used as a thickener. The retardant both lowers the combustion temperature of the material it touches but also causes the char rate of the material to increase, which reduces the amount of fuel available for the fire to burn. Many news agencies still refer to the tankers as slurry bombers but this is an outdated term from the 1950s when borate salt was used before the mix of chemicals that is in operation now.

The retardant drops are always very specifically targetted and are used to give the ground crews time to build fire defences or to contain its perimeter. As the name suggests it is not a suppressant but is effective for two to four hours to retard the relentless march of the fire. The tanker crews refer to their drops as "painting" and they will go as far as painting around structures to try to protect that particular home or business.

In the early part of the Fourmile Fire the winds plus an inversion stopped the drops taking place. Winds decrease the accuracy of the drops and the inversion made visibility hazardous to low-level operations in Colorado's mountainous terrain. Local media were quick to report that the tankers couldn't fly because of the high winds, when the correct way to report would have been to say that strong winds don't allow for effective drops.

Seven aircraft were deployed to Jeffco Tanker Base and included four P-3s from Aero Union, two P-2s from Neptune Aviation and a lone P-2 from Minden Aviation. The distance to the Fourmile Fire was only around 15 miles so the cycle of aircraft loading up, dropping and returning was very fast. The tanker base can handle two aircraft at a time for loading retardant, and aircraft on the ground waited for their turn to fill-up on the Stevens Aviation ramp until called down. The operation was very smooth with everyone playing their part and turnarounds were very quick.

In the end the fire grew to around 6,500 acres with 167 homes lost and 24 damaged. An amazing 533 homes were saved and there was no loss of life. Over 1,000 fire-fighters from 20 States were called in and, due to the difficult terrain, hot-shot crews were also involved in the back-country operation.

One of the strongest efforts by fire-fighters in this particular incident was in the historic town of Gold Hill, where fire lines were dug and backfires were lit to try to stop the wild-fire advancing into the area. Chris Finn, Gold Hill Fire Chief, told me that the fire was coming into town over two ridges and they had to evacuate the fire-fighters due to the possibility of being overrun. He says the town was saved by a couple of drops from the tankers. The story is picked up by eyewitness Dave Hitchcock who is a fire-fighter with the Timberline Fire Authority LT2. Dave was assigned to the west end of this fire near Gold Hill.

"We were working on saving houses on Dixon Road when the fire started closing in around us. We had to evacuate that area due to high winds, big flames, and potential loss of our escape routes. We moved to Gold Hill town and realized the fire was moving directly towards the town from the north. There were 150 foot flames in the trees just 150 feet from the north row of houses in town.

"Our assignment was to hold that area. Unfortunately, the flames were too large for a direct attack. At this point, our Division Leader decided to evacuate the town of Gold Hill. I agreed with this as the flame front was moving towards town extremely quickly. If the north row of houses had caught fire, I was sure the rest of the town would burn as well. I had very little hope of ever seeing this place in the same light again. We evacuated out of town and staged to Left Hand Road. I started reminiscing about this place. When I first came to Colorado in 1994, I moved to 698 Dixon Road, and at this point I did not know if the house I lived in was still around or not. I remembered the many fun times I had here... Gold Hill Inn for music and food, the general store for ice cream in a blizzard....

"I really thought we had lost this place. At this point I saw the first air-tanker of the day go overhead. I didn't think much of it, but I was glad to see they were finally flying. They were not flying the first several hours due to high winds. After we were staged for about 20 minutes, I heard our division leader ask for all trucks to come to one meeting point and we were going to try to go back to Gold Hill. I was astounded and I could not imagine why we would be going back in so soon. There was a HUGE fire going on right on the edge of town and our only route in put us directly into Gold Hill. What had changed?

"So we drove up to Gold Hill. I was apprehensive and excited at the same time. What was the town going to look like? We popped up Lickskillet Road and drove into the town and it was just how we left it! Right on! Gold Hill is still here!

"We got an assignment to go and work the north road, or Suicide Hill as its known locally. The first sight I see is a pile of firewood on fire stacked against a propane tank, which we put out. There was heat, smoke and flame behind the houses but we went behind them to do more structure protection and I noticed the houses were half covered in retardant. They were covered half way in a north / south respect and the fire was right up to the houses. This means in my viewpoint from the ground, that the pilot had NAILED his drop so effectively that the southern edge of his drop only covered half the houses, thus the rest of the retardant was a direct hit on the fire, while still protecting the structures. I said to a fellow fire-fighter 'he nailed that drop, huh?' So, we were quite excited to be working this row of houses, because if the fire-tanker drop had been there five minutes later, it would have been too late. The town is saved!!

"We then worked for another 12 hours in the area. Only looking back on the timeline did I realize that the retardant drop on Gold Hill was a perfectly timed operation. I don't have official details, but we were only out of the area for 20 minutes, and we had not seen planes flying all day. I think we got the first drop of the day and just in the nick of time, which was fantastic timing all around. I don't think our division supervisor asked for the drop either, but I think someone heard we were evacuating town and the tanker was sent here. The timing was impeccable. I also found out later there was a wind shift that helped turn the flames back on themselves, but it was so hot in there I think the houses would have still gone up. I'm happy to say I had a small part in saving the town of Gold Hill. There were several factors that saved that town: Wind shift, fire-fighters, retardant drop, luck and timing. Yahoo!!"

In the end the tankers dropped 148,349 gallons over 66 missions in four days on the Fourmile Fire. This turned out to be the most destructive fire in Colorado's history in terms of property damage. Although the Hayman Fire in 2002 burned a massive 140,000 acres only 133 homes were destroyed in that fire.

Back at Jeffco Tanker Base the crews had a chance to breathe after the last couple of days operations. Local people had donated cookies, books and brownies during this high-profile time and Papa Johns Pizza had even supplied a boatload of food for the staff. But, just as things started to return to a sort of normality a second fire took hold to the west of Loveland on 12th September, just north of Boulder. This fire gave me a very small window of opportunity to take a look at the helicopter operations that were based at Boulder Municipal Airport (MAP). This fire started at 30 acres but quickly grew to 400 acres in a very short space of time. This fire benefited greatly from the fact that tanker, helicopter and fire-fighter resources were already close at hand from the Fourmile Fire to the south.

On that Sunday afternoon an amazing 88,386 gallons from 38 missions were flown from Jeffco to fight the Reservoir Road Fire, and this quick and accurate attack seemed to hit the fire hard and restrict its area of devastation. From Boulder MAP meanwhile four Sikorsky S-64/H-54 Skycranes were busy sucking up water from nearby lakes to help extinguish the fire. Two operators, Erickson Air-Crane and Helicopter Transport Services had a pair of Skycranes assigned each to these two fires. A single Bell 205 N28HX was also utilised with a bucket.

A Bell 206B Jetranger belonging to Aviation Technology Services out of Centennial Airport in Colorado, was also seen in the later stages of this fire. It carried a new Light Detection And Ranging (LIDAR) based system developed by Lockheed-Martin to search for hot-spots in fires and is able to penetrate the smoke. This gave the company a real-time event on which to test their system.

I managed to catch a single Skycrane dipping in Flatiron Reservoir on its last trip of the day and, as it turned out, the last mission on this fire. The Reservoir Road fire ended up covering 925 acres and again no lives were lost. Tanker operations ended up dropping 102,263 gallons from 44 missions.

So in seven days Jeffco Tanker Base handled seven tankers flying 120 missions dropping 250,612 gallons of retardant. It was a very busy time indeed.

Thanks to Rita Basinger, Greg Cortopassi, Robbie Cline, Dave Hitchcock, Terry Krasko, Laura McConnell, Mark Michelson, Brian Scott and Steve Segin.

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