Firefighting from planes is fascinating. Some of the best planes are relatively small but because they can refill their water tanks very quickly, they can put more water on a fire in a given time than much larger planes. I've read that 4 C-130s from our local reserve unit are either in California or on their way. A C-130 can carry a lot of fire retardant but it has to return to base, land to a complete stop, refill, and fly back to attack again. Depending on air traffic and the distances involved, they might be doing good to get 1-2 drops per hour.

By contrast, the Bombardier 415 (formerly Canadair CL-415) is a smaller plane that can do a running refill by skimming across the surface of a lake or perhaps the ocean, refilling the tanks in a matter of seconds. It's one of the best firefighting planes ever made. The Mars firefighting plane is much larger than the 415 (about 4 times the water capacity). It also appears to have those scoops so it can refill rapidly. While it may not be able to do as many drops per hour, the larger capacity makes up for a slower cycle time.

Those high winds make it hard to operate those planes. Some of them aren't useful in some areas, either. For example, we had some massive wildfires in Colorado 4 years ago. To the best of my knowledge, those water scooping planes weren't used because the high density altitude reduces their load carrying ability and there aren't so many lakes as a water source.

Giant firefighting planes like that converted DC-10 can carry a lot of retardant but the number of drops per day is probably very limited because the turn-around time has to be pretty long. Still, there are times when being able to dump 12,000 gallons in a single drop can be very useful.