Burt Rutan's Favorite Ride
The Boomerang could be the safest twin ever built.
- By Steve Schapiro
- Air & Space magazine, September 2012
(Page 2 of 5)
“The first time I feathered [a Boomerang prop] and was slowing down with the other engine at full power, it wasn’t real obvious what I should do with the rudder pedals,” says Rutan. “It’s real obvious on a Baron—you better be putting rudder in and quite a bit.” So I had found part of the answer to my question Why? But I was curious about How? And even more curious to know What does it feel like to fly the Boomerang on one engine? I got the answer to that question because Burt Rutan decided to retire.
Safety First, Range Next
The Boomerang had its roots in two of Rutan’s earlier designs: the twin-engine Defiant and the high-performance, single-engine Catbird. In fact, he used the Catbird nose gear and engine on the Boomerang.
The Defiant has one engine in the front and another in back; such centerline-thrust designs enable an airplane to continue flying safely if either engine shuts down. Centerline thrust, however, has drawbacks. “When you have a pusher-propeller aft of the wing, it vibrates and creates noise,” Rutan says.
Rutan flew the Defiant as his personal aircraft for years, but he wanted an aircraft that had the range to go to Australia or Europe. He began thinking of a long-range twin at about the time the Catbird won the 1988 CAFE 400 race for efficiency, fuel economy, speed, and payload capacity. The Catbird still holds two speed records.
“I decided that I’m going to do a twin with the same type of attention to performance that I had put into the Catbird,” Rutan says. “My plan was to design the lowest-drag light twin that I could, and while I was at it have a lot of fuel, make a lot of range, and of course have the Defiant, or better, engine-out characteristics.”
At a presentation for the Society of Experimental Test Pilots, Rutan explained the Boomerang’s performance by walking his audience through a list of incremental changes to a traditional twin-engine design—a Beechcraft Baron, in fact. The series of changes transformed the conventional twin into an airplane that could fly symmetrically on two engines or one (see diagram, p. 42). In both the Catbird and the Boomerang, Rutan reduced drag by using a dolphin-shaped fuselage that narrows between the cabin and the tail. He modified airfoils used on his early craft, like the Voyager, to create an efficient, low-drag airfoil for the Boomerang’s wings.
Rutan knew he wanted a turbocharged airplane, like the Catbird, because it would enable him to fly at much higher altitudes, where, in thinner air presenting less resistance, the airplane could fly faster, or farther, using less fuel.
Built of lightweight composites, the Boomerang can carry five people, their luggage, and 171 gallons of fuel almost 1,900 miles (1,652 nautical). Running its two Lycoming engines (210 horsepower on the fuselage; 200 on the nacelle) at 75 percent power, a pilot can cruise that distance at 302 mph. Reducing the power settings to 37 percent will stretch the range to more than 2,960 miles cruising at 215 mph and 20,000 feet.