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.

Builder Dell Coller’s team has since added a CJ610 turbojet, slung under the center section. (EAA/Jim Raeder)
Builder Dell Coller’s team has since added a CJ610 turbojet, slung under the center section. (EAA/Jim Raeder)

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.