Columbia Helicopters and Simplex Aerospace have developed a large internal firefighting tank and delivery system for the CH-47D Chinook tandem-rotor helicopter and received FAA supplemental type certificate (STC) approval for it last December. The “Fire Attack System” (FAS) got its first real-world test under actual conditions in May dropping fire retardant on a wild fire near Ely, Minn. Columbia currently owns 11 former U.S. military Chinooks and has equipped two with the FAS to date. Both helicopters are operating under U.S. Forest Service exclusive-use contracts.
The 2,800-gallon-capacity internal tank is thought to be the largest designed specifically for fire suppression and certified for a helicopter, according to Cody Barton, Columbia Helicopters’ chief flight instructor and command pilot. “To our knowledge, there are no other helicopter operators in the world using an internal tank of that size, purpose-built for aerial firefighting,” he said. “The system is compatible with water, foam, chemical retardant or any other agent the USFS might supply,” Barton said.
Barton said the FAS equips Columbia’s Chinooks to tackle urban firefighting, since current U.S. government regulations forbid the use of a traditional external bucket and long-line system over structures and people. Also, he noted, since the tank is a “semi-permanently” installed system, the helicopter can be dispatched more quickly. “With the internal tank, we just take off and no longer have to take the time—about 20 minutes—to attach a 1,322-pound external bucket every time we need it,” he said. “Then, once attached, the bucket generates turbulence in flight, and slows our airspeed to between 100 and 110 knots. With an internally mounted tank, we can do 130 knots, which gets us to the fire that much faster.” He also said the FAS makes the helicopter more maneuverable while firefighting. “When it’s loaded with water, there is no real impact on aircraft handling. We continue to have a high degree of maneuverability, while maintaining operational safety standards.”
The tank is constructed as a single unit and uses a roll-on/roll-off method of installation and removal, which can be done at the field level. When installed, the tank is mounted over the cargo hook well, using specially designed components. The cargo hook was removed and the well underwent some modifications for the doors through which the water or retardant is dropped. The tanks can be filled directly from ground-based vehicles, or through a snorkel from lakes or streams. The pilot controls the doors and hover pump from the cockpit. Pilot instruction for the system consists of eight hours of ground and three hours of differences training.