Russia's Su-47 Stealth Fighter: What a Failure

Sebastien Roblin

Russia, Europe

The Su-47's design emphasized extreme dogfighting agility.

Here's What You Need to Remember: While the awesome-looking Berkut never evolved into a production fighter, it still played a useful role testing new technologies—and coincidentally, revealed how external observers could be quick to attribute extraordinary capabilities based on a few images of an awesome-looking jet.

In 1996, the March/April issue of Russian military periodical Air Fleet Bulletin published an innocuous-seeming photo of a meeting between Russian military chiefs and aviation industry counterparts. Sitting on the table before them were two model airplanes. One was an advanced variant of the by-then well-known Flanker multi-role fighter.

The other was a strange black jet with forward swept wings—that is, the wings seemed to be swept the "wrong way."

Whether the image amounted to an accidental leak or an intentional plant, it set off a firestorm of excited speculation in Western and Russian press forecasting a new cutting-edge jet that could outperform the F-22 Raptor stealth fighter, the production model of which made its first flight the same year.

In fact, the model represented an advanced tech demonstrator—the Sukhoi Su-47 Berkut ("Golden Eagle").

Early in the 1980s, as the Soviet Union introduced the fourth-generation Su-27 and MiG-29 jets to oppose the American F-15 and F-16, it thought ahead to developing a fifth-generation fighter to defeat the U.S.'s Advanced Tactical Fighter program which would eventually spawn the F-22 Raptor.

Mikoyan i Gurevich worked on the MiG 1.44, which arrived nine years late after the fall of the Soviet Union only to be canceled. Concurrently, the Soviet Navy sought a new fighter with good low-speed handling characteristics to fly off the steam-catapult equipped supercarrier Ulyanovsk, laid down in Ukraine in 1988.

Manufacturer Sukhoi chose to explore the concept of Forward Swept Wings (FSW) which in theory would enable greatly increase maneuverability, particularly at low speeds and high angles of attack, improved spin resistance, shorten take off distances, and enable greater range by decreasing air resistance. At the end of World War II, the Red Army had captured prototypes of a Nazi Ju-287 jet bomber under construction incorporating forward-swept wings.

However, forward-swept wings had not been widely adopted because they required extremely sturdy wings to withstand the aero-elastic twisting pressure exerted upon the wing roots. The added weight of the reinforcements canceled out the benefits of a forward-swept configuration.

Both U.S. and Russian engineers sought to get around this problem by using new composite-fiber materials to build lighter but sturdier wings. Grumman built two forward-swept X-29 technology demonstrators to test out the concept, which may have spurred Sukhoi's own interest in the scheme.

The Sukhoi design, which at various times was called the S-22, the Su-27KM, the S-37 and eventually the Su-47, also featured moveable canards, a second set of small wings next to the cockpit which further enhance maneuverability and lift. Together, the forward-swept wings, canards, and horizontal tail-stabilizers gave it a "tri-plane" configuration. In addition to these new elements, the S-37 retained a fuselage and twin-tail configuration from the Su-27 Flanker, though with unequal-length tail booms extending behind carrying rearward-facing radar and a breaker-chute.

Two D-30F-11 turbojet engines—similar to those on the powerful MiG-31 Foxhound interceptor—provided propulsion, though eventually a more advanced AL-41F thrust-vectoring turbofans were planned to take their place. Like the F-16, the S-37 was so responsive it relied on a fly-by-wire system to automatically correct its aerodynamically unstable characteristics.

The aircraft's good low-speed handling certainly made it attractive as a carrier-based fighter. But with the fall of the Soviet Union in 1991, both the Ulyanovsk and the Navy's demand for the new carrier-fighter were scrapped. The Sukhoi project was far enough along, however, that the manufacturer was able to privately fund the completion of one demonstrator model.

Western publications particularly attributed stealth characteristics to the jet. The Berkut may have incorporated radar-absorbent coatings and materials, and Sukhoi planned for it to feature an internal weapons baby which could accommodate four long-range R-77 air-to-air missiles (then still under development), in addition to four external short-range R-73 missiles. However, Sukhoi would later admit the Su-47 had not been conceived foremost as stealth jet.

Instead, the Su-47's design emphasized extreme dogfighting agility. The demonstrator jet made its fi

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