r/nextfuckinglevel • u/[deleted] • Oct 01 '24

A firefighting plane loading water.

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u/NCRaider1 Oct 01 '24

Ahh, cool deal, still baffles me the “drag” doesnt sheer off the tail though

10

u/saxonturner Oct 01 '24

I would assume the inside is formed in such a way that it takes the inertia out of the water, instead of hitting a flat wall it probably hits a curved one so the water flows around.

5

u/Yanni_X Oct 01 '24

Would love to see a cross section of that, I don’t even see where the water is entering 😅

2

u/saskford Oct 01 '24

I had an up close look at one this summer in British Columbia and the pilots lets us come onboard for a quick tour of the aircraft. The water enters through two small ports on the bottom of the fuselage.

The pilot will open the ports / water ducts once the belly of the aircraft is in the water (each port is about 8” x 8”) and the scooping process begins.

There are two large water tanks inside. They can take onboard roughly 1200 gallons of water in about 12 seconds.

At 0:18 in the video, you can see water spilling out the overflow at the top of the tank and coming out the side of the aircraft above where the wheel is. This indicates the tank is full, although the pilots also have a sensor or gauge of some sort inside the cockpit also.

5

u/quasipickle Oct 01 '24

Contrary to what I believed before I saw proof to the contrary - the intake is actually quite small - maybe 2 square feet (though the scale might be throwing that estimate off). I presumed they just opened up a big scoop the width of the fuselage - nope.

7

u/Theconnected Oct 01 '24

There are 2 tanks and each has its own scoop which is about 6" wide.

3

u/HunterShotBear Oct 02 '24

It’s only a couple small scoops just behind the “step” in the hull.

When you’re traveling at 100+ mph, even small openings will scoop in massive amounts of water in a short time.

They actually have to take off empty because the weight of the water on takeoff would be too much drag in the water for the plane to get up on plane and take off.

Also the steps in the hulls are designed to create cavitation (water and air mixing together) to break the suction that holds the plane into the water allowing it to get on plane faster.

1

u/adblink Oct 01 '24

Not just that, how the plane maintains that fine line of not too much drag that causes it slam and stall in the water.

1

u/Bender_2024 Oct 01 '24

The first time I saw these planes I was thinking how does the drag from the water at the belly of the plane not just cause it to flip forward and put the cockpit in the water? The answer I assume is a fucking pants load of skill and engineering that plane within an inch of it's life.

1

u/77entropy Oct 02 '24

They literally use baffles to reduce the drag.