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A method and apparatus for aerial fire suppression utilizing a potable fire retardant chemical dispensing system, readily adaptable, without extensive aircraft modification, to various makes of aircraft, for dispensing current types of forest and range fire fighting chemicals. The aerial delivery system is self contained and reusable. It enables cargo/utility aircraft to carry and dump a load, under control. The aerial delivery system is capable of attachment at the wing box, pressurized delivery from the nozzles, and nozzles directed straight downward.

Quote (http://en.wikipedia.org/wiki/Evergreen_International_Aviation)

Evergreen International Aviation, Inc. is a global aviation services company based in McMinnville, Oregon, United States. Founded in 1960, Evergreen is primarily known for commercial helicopter operations in agricultural and forestry applications...Delford M. Smith founded the company as Evergreen Helicopters in 1960.[1] Smith was a leading innovator in the commercial use of helicopters, and his company was the first to use helicopters for spraying fertilizer and herbicides, spreading seeds and fighting forest fires.