The Canadair CL-415 Super Scooper has a 56” wingspan, removable wing, twin engines, is built of pink FFF, and can scoop and dump water.
Specs:
Wing Span: 56 in.
Wing Area: 380 sq. in.
Flying Weight: 28 oz. without water (but I haven’t painted it yet)
Water Load: 19 oz. by weight
CG: 2.25” behind LE
The CL-415 is a standout modeling subject for several reasons:
1. It has almost no compound curves, making it a perfect project for foam.
2. It has awesome winglets all over.
3. It comes in lots of bright color schemes, most using fire engine red and cub yellow.
4. Speaking of fire engines, it has flashing red lights.
5. It can scoop up water and dump it on forest fires (or the neighbor’s dog, whichever is more appropriate).
There is no water rudder, but slow speed taxi is easy with differential throttle mixed with the rudder. On my first flights high speed taxi always ended with a pontoon catching the water and causing the aircraft to spin around, but I soon learned that keeping the nose up with up elevator during taxi fixed that problem. I have not flown from grass yet.
Takeoffs and landings are easy. When empty the wing loading is light and it lifts off at a very slow speed. Control response in flight is good. It does good scalelike loops and rolls.
Instead of separate flaps I used full length ailerons set up as flaperons. While they are effective as flaps, the ailerons produce a lot of adverse yaw when the flaps are down.
The scoop function works well. I occasionally get debris stuck on the scoop, but it hasn’t caused any problems. The tank fills in about 10 seconds, and water can be seen coming out of the overflow holes.
Dumping also works well. My initial concern was of water leaking out of the tank through the hatches, but water leaking in through the hatches is more of an issue. I modified my original hatch design to be hinged at the front which mostly fixed this, and the occasional cycling of the hatch while airborne takes care of the rest. If you intend to do extended flying without using the dump function, the hatch could be temporarily sealed with tape.
I initially thought it was overpowered for a scale plane. Then I lowered the scoop and filled up with water. Now it needs all that power and flies like a pig! But this was planned from the beginning, and I suspect is very prototypical. What do you expect when you put 19 ounces of water in a 28 ounce plane? The contrast keeps it interesting.
Flight times are about 15 minutes with some reserve.
