Wildfires in California have been on the rise at alarming levels in recent years and the trend only looks like continuing.
By mid-July 2021 CAL FIRE – the US state’s fire service – had recorded nearly 5,400 wildfires. These had destroyed a combined area of 300,000 acres. That compares with a five-year average of 3,200 incidents destroying 107,000 acres for the same seven-month interval.
To tackle this ever-growing problem, which most accept is the result of human-induced climate change CAL FIRE call on a fleet of more than 60 aircraft that range in size from 13-tonne behemoths like the Grumman SR-2 Airtanker to lightweight Rockwell OV-10s and Huey and Sikorsky helicopters. Since many wildfires take place in remote parts of the state, the CAL FIRE fleet – the largest civil aerial firefighting fleet in the world – often finds itself deploying to remote locations. Refueling is done at unmanned airfields or in some cases in farmer’s fields given over for the purpose.
ATC at these unmanned airfields is overseen by personnel from the US Forest Service using a handheld device. But if the fire grows in severity and more aircraft are called in, airfield operations become too difficult to manage in this way, says veteran air traffic controller Titus “Stretch” Gall.
“The number of aircraft gets to a point when it’s not manageable by Forest Service personnel because they don’t have the training or the authority to clear an airplane to take off or land,” says Gall. “All of their instructions are advisory in nature. If you need positive control then you must have an FAA-certified controller issuing those instructions.”
Faced with this situation the Forest Service has two options, says Gall, who worked ATC at the FAA for 32 years and left to start the mobile ATC company Tower Tech. “They can close the airport to civil traffic, which is something they don’t like to do, or they can call in air traffic control. So they call us.”
Trailer-mounted
Tower Tech operates a fleet of three trailer-mounted mobile ATC towers that can be on-site and operational within 24 hours. While most of their deployments are within California, the firms controllers also travel to any of the seven western states of the USA. At the time of our conversation, for example, Gall had a tower in Arizona helping the firefight against the Backbone Fire, a blaze that burned for a month and destroyed 40,000 acres of woodland near to the town of Pine.
Gall got the idea for the mobile units after working as a volunteer FAA controller for wildfire response and noticing that much of the equipment in the temporary towers being used was “vintage”. The Forest Service was also providing all of the other amenities, including accommodation and food for the controllers, and power to the ATC towers. “I just thought it would be better if the Forest Service could make one phone call and get everything,” says Gall. “A trailer and FAA-certified air traffic controllers that required no support from them.
“We take care of our own fuel, lodging and travel. There is nothing for them to do other than call us and we show up.”
The decision to call in Tower Tech comes from either the Forest Service or CAL FIRE. It is usually “the air operations manager on that fire that makes the determination,” says Gall. A tower is then driven to the airfield site and he asks for approval to operate from the FAA.
“We have a negotiated protocol with the FAA that as soon as we get a call to go anywhere we call them to request a tower frequency and a ground control frequency for the site,” he says.
An FAA examiner is sent to the site to certify Tower Tech for the temporary assignment. “Once we get that blessing from the FAA on day one, we’re good at that airport for the next 120 days,” says Gall.
The tower is manned by two controllers who have at their disposal eight radios. Power is provided by two 12,500-watt generators and they carry with them 100 gallons of diesel and a similar quantity of water. The tower has sleeping accommodation, a fully-fitted kitchen, shower and a satellite TV hook-up.
Gall says, “If you’re going to put somebody up in the field in a temporary tower you have to provide them with everything without having to go elsewhere because sometimes these locations are quite remote.”
Clearlake
One of the most remote assignments the copy has done was a wildfire they helped to tackle near Clearlake, California in 2020.
“We were operating out of a dirt field rented by the Forest Service from a local farmer,” says Gall. “We had 20 helicopters coming in and out of that field. There was no civil traffic but it was very busy with helicopter traffic.”
In situations like that the helicopter support teams drive in pods containing fuel and portable helipads for takeoff and landing. There is a deck manager responsible for the layout of the helipads in the field.
The helicopters fly into the field for refueling only. This task completed, the helicopter takes off, but before they can return to fight the fire they must take on either fire retardant or water. The fire retardant is usually picked up from portable dip tanks the size of small swimming pools located at strategic points en route. Water, meanwhile, can come from a variety of sources.
“It can be a river, a lake, a farmer’s pond,” he says. “I’ve seen them take water out of a swimming pool in somebody’s backyard. They get the water wherever they can find it.”
While Gall can call on a staff of 17 controllers, he often likes to work the towers himself. Even though the job has lost none of its appeal, he says it’s hard to witness up close the damage climate change is having on his beloved state. “It makes me feel like I’m out there chasing ambulances,” he says. “We’re getting busier and busier and while that’s wonderful for business it’s really sad to watch.”
Hurricanes
Climate change is also cited as the cause of an increased frequency in extreme weather events such as hurricanes.
In October 2018 Hurricane Michael, a Category 5 storm, struck the Florida coast killing 59 people and causing billions of dollars worth of damage. One of the locations that found itself in storm’s path was the US military’s Tyndall Air Force Base in Florida’s panhandle.
Much of the base was destroyed, including the radar approach control (RAPCON) building, which lost its roof in the storm. Meanwhile the ATC tower was rendered inoperable after the hurricane blew out several of its windows, drenching all of the equipment with torrential rain. The damage forced a halt to operations at the air base. As a temporary fix the military deployed a mobile ATC tower to the site. The tower, known as the Deployable ATC Automation and Communications System (DAACS) was operational for two months while the base repaired its RAPCON.
DAACS is one of two mobile ATC systems manufactured by the US defense contractor Raytheon for the US military. Whilst DAACS plugs into existing radar infrastructure, the other, which is called ATNAVICS (Air Traffic Navigation, Integration and Coordination System), comes equipped with a mobile radar. The ATNAVICS system is mounted on two Humvee trucks, says Jessica Farr, program manager for ATNAVICS at Raytheon.
“One carries the ATC operations center and the other has the radars,” says Farr. “It can be set up anywhere in the world, as long as the ground is flat. It’s really quick to transport. It can be flown in on a helicopter and driven straight off and set up and operational within an hour.”
Up until now Raytheon has been under contract to only supply these units to the US military. But as that contract expires the company is now looking to expand sales to include disaster relief agencies in other countries, says Farr.
Another manufacturer of mobile towers is the UK-based company Mobile ATC Systems. Like Raytheon, Mobile ATC have also been providing towers for military and industrial clients – such as the UK’s Royal Air Force – and are now keen to see their technology used for disaster response.
According to Colin Chapman, Mobile ATC Systems’ managing director, a mobile tower could be stored in a location close to a region where natural disasters occur frequently and then airlifted in when needed.
“The unit can be flown in on a Hercules loading bed and then air-lifted the rest of the way by a Chinook,” he says. “Once you bring in these assets to bear you can get it in place quite quickly.”
But despite widespread interest, relatively cash-strapped aid agencies have been unable to raise the funds to buy the technology.
Chapman says: “Whenever you speak to people involved in this area - whether it’s the UN or the military - they all say that mobile ATC towers should be in place in the field. But for now, nobody wants to pay for it and put it there.”
Drones to provide disaster relief
A growing number of agencies are investigating the use of drones in emergency response and disaster relief. For example, Switzerland’s national rescue agency Rega has been testing a drone that can find people that are missing or in difficulty in the Alps.After the 2018 California Camp Fire, the most devastating wildfire in the state’s history, relief agency drones were used to collect images of the fire and its aftermath to help in the disaster response. Drones also played an important role following the 2018 collapse of the Morandi Bridge in Genoa, Italy, where they were used to help fire crews look for survivors.But the more drones that are used in relief operations, the greater the risk of mid-air collisions occurring are with other aircraft. This concern led to NASA partnering with the Japan Aerospace Exploration Agency (JAXA) in 2016 to look at the use of unmanned traffic management (UTM) systems in disaster response.NASA, which is already researching its own UTM system to enable the large-scale commercial application of drones at low altitudes partnered with JAXA to develop a system to manage resource allocation during disaster response operations.After two years of collaboration the two agencies ran joint flight tests with drones as part of a large-scale disaster drill in Ehime Prefecture, Japan, during October 2018. According to a NASA research paper the flight tests “successfully demonstrated” the application of drones to disaster response and “showed they can safely cooperate with manned aircraft to improve response efficiency”.
Restarting flights after a disaster
Resuming flight operations is a key part of disaster response. If transport routes on the ground are blocked or destroyed, flights are the only way for aid agencies to get food and water supplies, medical equipment and other essentials to the local population.At the start of relief efforts, flights might have to fly into uncontrolled airports with very little ground support, if any.“They might have a person on the ground with a handheld radio or they might not have anything,” says Colin Chapman, of tower supplier Mobile ATC Systems. “The aircraft might just land using visual flight rules.“With a handset they’ll get things moving but at a really reduced flow-rate. With a mobile tower you can get much more infrastructure in place. Support comes in much faster simply because you are able to deal with more capacity on the airport.”This is because the ATC tower can provide much more ground-to-air coverage – a range of 70-120 miles (110–200km) versus “a handheld radio or a small base station which will only give you 20-30 miles coverage absolute maximum.”Mobile ATC’s towers - like Raytheon and Tower Tech’s systems – give “all the functions of air traffic control” including weather monitoring systems can be deployed in a trailer. Raytheon’s ATNAVICS (Air Traffic Navigation, Integration and Coordination System) has a radar outfitted to a Humvee. The radar needs to be set up close to the runway but another Humvee housing the control centre can be located up to one kilometer away, says Raytheon’s program manager for ATNAVICS, Jessica Farr.