If you had asked a Soviet test pilot in 1940 to name the strangest aeroplane he had ever been ordered to fly, there is an excellent chance the answer would have come back as four syllables: Дэ-Бэ Эл-Ка. The Belyayev DB-LK. Two fuselages, no central cockpit, forward-swept outer wings, glazed bombardier stations grafted to the tail ends of each engine nacelle. It looked less like an aeroplane than like something a child had built from the spare parts of three other models.

The test pilots had a less polite name for it. They called it Курица. The Chicken. They did not mean it kindly.

A glider with ideas

Viktor Belyayev was not a fringe figure in Soviet aviation. He had worked under Andrei Tupolev throughout the 1930s on a series of large heavy bombers and had a deep engineering pedigree. What he also had was an obsession with the aerodynamic possibilities of the flying wing. His "batwing" glider, the BP-2, had been a successful test article in the mid-1930s, and Belyayev believed its short-fuselage, long-chord wing geometry could be scaled up to a combat bomber.

The DB-LK — Дальний Бомбардировщик-Летающее Крыло, "Long-Range Bomber — Flying Wing" — was the result. The design did away with the conventional fuselage entirely. The two M-87B engines sat at the front of two short fuselage pods, each ending in an extensively glazed tail cone that housed a radio operator/gunner station. The pilot and navigator sat in cockpits at the front of the pods, with the bomb load slung between them inside the wing centre section.

"The chicken"

Test pilots were reportedly unwilling to fly the DB-LK at all, citing the unconventional layout and the complete lack of flight envelope data for the configuration. It eventually fell to LII test pilot M.A. Nyukhtikov to take it up, after extensive fast-taxi trials — one of which ended with a collapsed undercarriage.

When the DB-LK finally flew, the performance was genuinely impressive on paper. The forward-swept outer wings — swept just 5 degrees 42 minutes, but swept forward, anticipating the much more famous experiments of the German Junkers Ju-287 and the American Grumman X-29 — produced excellent low-speed handling. The defensive armament had clear fields of fire that no conventional bomber could match.

What went wrong

The list of problems was not catastrophic individually — it was simply long. The take-off run was excessive because of high sensitivity to centre-of-gravity variations. The pilot cockpits had terrible visibility forward because they were tucked behind the propeller arcs and the wing leading edge. The crew complained that engine exhaust gases collected inside their compartments, forcing them onto oxygen masks. The crew could not see each other; the intercom was the only contact between cockpit and tail.

Most importantly, the design promised 547 km/h but delivered only 488. That offered no real advantage over the bombers already in service, and it was considerably slower than the next-generation Pe-2 entering service. The Soviet Air Force, the VVS, looked at the DB-LK, looked at its problems, looked at the production resources it would require, and said no.

A redesign as a dive bomber was discussed but abandoned. The single prototype's ultimate fate is unrecorded; it was most likely destroyed during the Second World War.

Sources: Wikipedia; Plane-Encyclopedia; HandWiki; Military Matters / Forgotten Aircraft; Soviet engineering journals (1940 archives).