Aviation history is littered with examples of siamesed, twin-fuselage airplanes, from the 1915 Blackburn TB double-floatplane Zeppelin attacker to today’s White Knight Two and Stratolauncher spacecraft carriers. In the early years, it was an easy way to double horsepower without designing an all-new twin. Later it became a means of conveniently increasing crew, fuel or cargo capacity. The most successful of them was the North American F-82 Twin Mustang, but the World War II Heinkel He-111Z—a five-engine, two-fuselage kludge in-tended to tow the bloated Messerschmitt Me-321 troop-carrying glider—had its day in the sun as well.
An audacious new mirror-image mutant recently joined their ranks when a free-thinking team of airshow pilots mated two Yakovlev Yak-55 radial-engine, single-seat aerobatic aircraft to create what has inevitably been renumbered as a “Yak-110.” It required a carefully engineered and fabricated center section joining the two fuselages, plus mating of the horizontal stabilizers and trimming of the outboard horizontal tails. Both cockpits remain fully operational, and the Yak-110 has been extensively test-flown, including a full range of conventional aerobatic maneuvers.
Now builder Dell Coller, of Dell Aero Speed, in Caldwell, Idaho, is adding a 3,000-pound-thrust GE CJ610 turbojet to the airplane, slung under the center section. Essentially a Lear 25 engine, it will provide the equivalent of roughly four times more horsepower than the Yak-110’s two nine-cylinder, 360-hp Vedeneyev radials already generate.
The first airshow performer to team a CJ610 with a piston engine was Jim Franklin, who in 1996 began flying his Jet Waco UPF-7. That airplane, and Franklin, were lost in an airshow midair in 2005. In 2014 Coller’s Screamin’ Sasquatch Jet Waco, a 1929 Taperwing with a CJ610, was introduced, and has since become a fixture at airshows.
The Yak-110 recently appeared at this summer’s EAA AirVenture in Oshkosh, Wisc. Like the F-15, F-16 and several other superfighters, it has a thrust-to-weight ratio greater than 1-to-1, which provided for some decidedly unconventional aerobatics.