The Yarnell Hill Fire was a lightning-sparked wildfire which killed 19 members of the Granite Mountain Hotshots near Yarnell, Arizona, on June 28,...
Night Vision Goggles Bringing Wildfires Into Focus - Part I
Many fire agencies dream about being able to fight wildfires effectively from the air at night when humidity levels rise and wildfire activity subsides.
Since the 1970’s, when the U.S. Forest Service first started experimenting with using night-vision goggles (NVG) with a small Type-3 helicopter in Southern California’s Angeles National Forest, a number of agencies and departments have explored the advantages that NVG has in aerial firefighting.
From those fitful early steps, NVG has expanded into something which is in regular use by many Southern California fire agencies, including Los Angeles County, Los Angeles City, Ventura County, Orange County Fire Authority, and San Diego Fire-Rescue Department.
NVG Down Under
These advantages have not gone unnoticed internationally, with night-flying experiments conducted in Victoria, Australia, a few months ago culminating in a series of trials to determine whether NVG would be safe in the pitch-black Outback and rural areas devoid of any manmade light sources.
Wayne Coulson, CEO of Coulson Aviation, was involved in the trials, working with Victorian agencies by providing helicopters outfitted for use with NVG to Country Fire Service.
Innovation is nothing new for Coulson Aviation. In addition to their NVG work, they also have a number of C-130Q air-tankers deployed to various fires across the U.S., including their latest, Tanker 134, which was going through the final stages of approval by U.S. Forest Service at Reno, Nevada, the day I interviewed Wayne. Their new 737 conversion, the Fireliner, which in addition to carrying retardant, can also transport up to 69 firefighters to airports near a wildfire, was in the last stages of getting its final approval from CALFIRE to begin fighting wildfires.
Coulson discussed how things went in Australia and what may lay ahead in the future for NVG Down Under.
“It was a two-year process with Emergency Management Victoria, which was the sponsor,” Coulson explained. “CASA [Civil Aviation Safety Authority] agreed to bring in experts who had trained with NVG to do the [firefighting] work as long as they could do it safely.”
Using the nose-mounted infrared camera on Coulson’s S-76, the firebombing trials could be carefully documented for examination afterwards by CASA and other participants. By shadowing the Coulson S-61, the S-76 also took much of the risk out of the firebombing runs. When the S-76 illuminated the target with a laser mounted on the aircraft, the S-61 knew exactly where to deposit its 4,000 liter load.
Coulson discussed the fundamental difference between daytime firefighting and battling fires at night.
“In the daytime, you get an emergency call and your firefighters go fight the fire, it’s very reactive,” he explained. “But at night, you’re more proactive, with a level of accountability. We included a [S-76] air intelligence helicopter that has a variety of tools in it.”
The laser designator is used to illuminate the target for now, but in the future, the process will be even more automated. “On our tanking systems on the C-130s, the Fireliners, and the helicopters we have GPS locators which, in the evolution of firefighting, will allow the tank on the aircraft to automatically drop between two GPS points,” said Coulson.
“We are using technology to assist us on the ground,” Coulson continued.
“The firebombing helicopter doesn’t go into an area without a pre-determined target. At night, every drop is a precision drop because it’s so expensive, so we don’t send a firebombing helicopter into a fire area without a pre-determined strategy, unlike the daytime.”
As mentioned earlier, there are advantages to fighting wildfires at night. Water drops are a lot more effective at night when it’s cooler than in the daytime when it’s 100 degrees. Gel can also make drops more effective by getting more water onto the fire. A water drop into a wildfire can lose upwards of 70% of its mass before it reaches the heart of the fire due to evaporation. Gelled water can decrease the evaporation substantially, sometimes to less than 30%, further boosting the effectiveness of water drops into wildfires.
“We have a gel injection system in the helicopter and it really does an amazing job when it’s injected at .5%.”
Dipping into water sources to refill a helicopter’s tanks can also be somewhat daunting at night, but NVG takes much of the danger out of the process. “One of the advantages we have dipping at night is the rotor diameter of the S-61. Other helicopters can have problems from the mist coming off the surface of the water clouding the windscreen so that the pilot can’t see.”
NVG also provides a time advantage by allowing a helicopter to dip into a water source instead of having to land to reload the tanks. “It wouldn’t be economically viable for us to land, so being able to dip at night in the Outback using NVG is critical to our operation.”
NVG aren't without risk
Even though there are tremendous advantages to fighting wildfires at night, there are risks. One Orange County Fire Authority pilot recalled heading into a wildfire at night, only to find that he had trouble picking his way back out, due to the abundance of light from the fire reflecting off smoke, obscuring their view. Other considerations include:
- A radically reduced field of vision from 240 degrees to as little as 40 degrees. This forces pilots to keep their heads on a slow swivel, constantly scanning. The pilot also has to peek under the goggles to glimpse gauges in the cockpit.
- Fatigue goes up dramatically at night. Local, state and federal rules calculate night flying increases pilot fatigue by 1.6 times that of day flying, which translates to 37.5 minutes for every hour of daytime flying.
- Night vision doesn't allow pilots the depth perception to judge altitude, so radar altimeters are needed to keep the aircraft at the correct altitude.
- Power lines and other hazards that are seen plainly during the day are virtually invisible at night, even with night vision goggles.
- Spray kicked up while refilling tanks or Bambi buckets over a water source can blind a pilot by coating the windshield, something which is not recognized as quickly at night as it would be during the day. If the windshield was dirty when the aircraft arrived over the water source, spray deposited on the windshield can turn to blinding mud.
- NVG program costs can be high, running $100,000 or more for equipment and training. GEN III+ NVGs, such as the military-grade AN/AVS 9 Aviator goggles, cost upwards of $12,000.00 apiece. And retrofitting cockpits to work with NVG can also be costly, as CAL FIRE, the California state firefighting agency, found out years ago when then-Governor Schwarzenegger balked at the cost of buying and retrofitting nearly a dozen NVG-capable S-70 helicopters to fight wildfires at night.
Although there are risks for NVG, aerial firefighters also see tremdenous advantage to this, especially in the face of climate change. It's about future proofing the industry, and ensuring communities can stay safe as wildfire seasons continue to grow.
Looking to the Future
Following months of preparation and trials, Coulson Aviation is ready to go to work on bushfires in the coming season. “Because we’ve trained to fight bushfires at night in the wildland, we hope to be permitted to do that this coming season,” said Coulson. “Our aim is to secure contracts for 3 S-61 helicopters, one of which will be 24-hour on-call, with two 12-hour pilot shifts.”
But Australia is not the only potential client for Coulson’s NVG-equipped aircraft.
“We’ve also been talking to Portugal, Chile, Argentina, and the European Union about contracts.”
So there may be many more helicopters pounding wildfires from the air by night in the near future. It’s merely a question of who will be the next agency to throw their hat into the NVG arena.