Water-bombing aircraft are pretty standard wildfire-fighting equipment. Helicopters that spew fire onto the forest? Not so much.
Although flying around an already-burning forest with a flaming propane tank might seem counterintuitive, there is logic to the Apocalypse Now madness. Think back to your fire triangle: by burning tinder that's in the path of the advancing wildfire, firefighters can deny the fire fuel, helping bring it under control.
Controlled burns are normally achieved by deploying wilderness firefighters, who use hand tools to prepare the burn. The helicopter flamethrower — really just a propane or gasoline tank, suspended underneath a heli — lets firefighters ignite a burn in hard-to-reach or dangerous areas. Plus, it lets the pilots fly around with a flaming propane tank, which I'm guessing is the best thing anyone's ever been paid to do.
CAL-FIRE has deployed a helicopter to help stem the advance of the Rocky Fire, which is burning virtually out of control in the Northern Bay Area. Footage of the helicopter doesn't seem to be available, but this video (from 2009) should scratch that flaming-heli itch quite nicely.