This hot video (4min 50sec) gives you a pilot's-eye view of what it's like for airborne fire fighting crews when fighting fires. These guys provide aerial support for firefighters when fires get out of control, or are burning in areas that can't be reached by ground crew. The planes are PZL M18A Dromadas, however they are slowly being replaced by Air Tractor 602 and 802s.
The worst forest fire ever recorded in North America was the Miramichi Fire which took place in 1825 and and killing 160 people burning 3,000,000 acres (12,000 km²) in New Brunswick, Canada. The largest forest fire ever recorded in the United States was the Peshtigo Fire in Wisconsin which burned 1,200,000 acres (4900 km²) in 1871.
In the US, two other fires reached 1,000,000 acres (4,000 km²): the Silverton Fire in Oregon in 1865 was the worst recorded fire in state's history, and the Thumb Fire in Michigan in 1881 killed 250+ people.
In New Mexico, in 2000, the Cerro Grande Fire burned 48,000 acres (190 km²) It burned about 420 dwellings in Los Alamos, New Mexico, damaged >100 buildings at Los Alamos National Laboratory; $1 billion damage, worst fire in state's recorded history. The Hondo fire in the San Cristobal area burned 8,000 acres (32.3 km²) and destroyed 34 structures in May 1996. On July 4, 2003, the Encabado Fire, that began less than a mile from the world renown Taos Pueblo historic monument burned 5,400 acres (21.8 km²) and burned for eleven days.
Please Note: This video takes place in Australia, but it was just to thrilling and descriptive of what our own airborne fire fighters experience that it was included.