747 Fire bomber

Nice video, thanks for posting it. I haven’t seen it before.
The water is probably red because of some sort of fire-killing product in it?
Any idea where this video has been made?

Normally air tankers drop “slurry” which not only kills the fire but also has chemicals to encourage new plant growth…a kind of fertilizer. Because of that, the stuff can be corrosive. The red color is used to mark previous drops.
I don’t know if the test drops used colored water or real slurry.

The tests were done at Evergreen’s base at Marana, Arizona just north of Tucson and better known as a ailriner storage field.

No word on any approval or plans to uses the plane operationally.
It would be something to see!