Issue link: https://iconnect007.uberflip.com/i/1228683
68 SMT007 MAGAZINE I APRIL 2020 The Boomerang is significant because it looks asymmetric, but it is symmetric when the Baron is asymmetric due to the P-factor. You have a propeller where if the wind goes straight into it, the thrust of that propeller blade is the same as it goes around like this. But when you're slow, which is when you lose control, you're flying nose-up. The air is com- ing in from the bottom. When the blade is in one direction, it's going into the flow, but when it's in another, it's going with the flow. One propeller blade makes more thrust in one direction than in another. Feinberg: There's no balance. Rutan: The net effect of that is the thrust line is not in the crankshaft; it's about nine or so inches to the right. The Boomerang looks asymmetric. Between where the CG is and the shorter engine on one side, at your low speed where you have the P-effect, the thrust of both engines moves to the right, and the Boomer- ang becomes symmetrical. Not only does it become symmetrical, but your engines are blowing on your tail, which gives you more control and more stability. A Boo- merang is absolutely dramatic. The minimum control speed on a light twin is defined by the fact that you have the full rudder in as you slow down, and even though you have the full rudder in and you're push- ing like hell with your right foot, if you fly a little bit slower, you can no longer go straight. You'll start to turn. You go a little bit slower than that, and you could be on your back. That's the definition. With the Boomerang, you don't even need to put your feet on the rudder pedals. You can fly it at its minimum speed with the full half- stick, which doesn't stall. It does a bucking motion, single-engine. You can turn into the dead engine as tight as you want to. It's a bizarre, extreme difference in safety. On top of that, the Boom-erang has a tre- mendous advantage in efficiency. I built the Defiant, which is a push-pull twin, and then the Boomerang. If you take a Boomerang with four-cylinder engines—which normally cruises at 260 knots—and slow it down to 185 knots— which is the maximum cruise speed of the Defiant—the higher altitude, you're going the same speed. The Boomerang has exactly half the fuel flow of the Defiant—twice the miles per gallon. The bottom line, in all of my work, is the air- plane that has the most dramatic benefit for safety and for efficiency and range. That's why the Boomerang is probably my best work. Yes, the Voyager flew more than twice as far as that B-52 did, and it had to be built frail, but it was pretty obvious what I had to do with the Voy- ager. I had to make the structure extremely light, and I had to make it stiff enough to carry a lot of fuel. With the Boomerang, it wasn't obvious what I had to do to make that safe. In fact, most people look at it and say, "I'm not riding in that. It doesn't look safe." That's why there have been three attempts to raise money to certify and build a Boomerang, and none of them have raised the money. Rutan's Boomerang twin-engine design.