Design solutions for the program of the Su-47 Berkut experimental fighter with a reverse-swept wing are used in the development of the Russian heavy strike drone.

This was reported to RT by the press service of Rostec.

“The experience of working on the reverse-swept wing for the Su-47 Berkut is used by ONPP Tekhnologiya when creating structural elements of the airframe of a promising Russian heavy strike UAV,” the state corporation said.

In "Rostec" did not specify what kind of apparatus in question.

However, according to information disseminated in the media, at the moment, enterprises that are part of the state corporation are working on the S-70 Okhotnik unmanned aerial system.

This UAV is made according to the "flying wing" scheme and has low radar visibility.

In the near future, the United Aircraft Corporation (UAC) is to launch mass production of the S-70.

The first deliveries of the S-70 to the army are scheduled for 2024.

Strength and lightness

Recall that the Su-47 Berkut first took to the air a quarter of a century ago, at the end of September 1997.

The experimental aircraft was piloted by Sukhoi Design Bureau test pilot Igor Votintsev.

The Berkut was conceived as a multifunctional stealth fighter, capable of developing supersonic speed in cruising flight modes and conducting all-aspect shelling of air targets in close combat.

Along with this, the aircraft must be highly maneuverable.

To achieve this quality, the Sukhovites decided to use a reverse-swept wing, which is distinguished by reduced air resistance and good performance at high angles of attack.

Work on the Berkut started in the 1980s with the support of the USSR Ministry of Aviation Industry.

After the collapse of the Union, the staff of the Sukhoi Design Bureau continued to implement the project on its own initiative.

The experimental aircraft was presented to the general public in 1999 at the MAKS international air show in Zhukovsky.

Due to the peculiarities of aerodynamics, the wing of the Su-47 experienced enormous loads.

To increase its rigidity, Russian engineers decided to integrate composite materials into the design.

As RT was told in the press service of Rostec, for the implementation of the reverse-swept wing project with a given level of physical and mechanical characteristics based on carbon bundles, the latest KMU-7 material for that time was developed.

It was made by specialists of the All-Russian Research Institute of Aviation Materials (VIAM).

  • The tail section and nozzles of the Su-47 Berkut engines

  • RIA News

  • © Grigory Sysoev

“This material not only met the stated requirements for strength and other parameters, but also made it possible to create the Berkut wing from large-sized panels.

Thanks to this, the designers were able to minimize fasteners, improve aerodynamics, reduce the weight of the airframe and reduce its radar visibility, ”RT told Rostec.

In general, the new technology of long composite panels made it possible to increase the rigidity of the wing structure without a significant increase in mass.

According to the state corporation, the wing of the Berkut consisted of 50% polymer composite materials (PCM).

There were no similar structures in our country at that time.

This result was achieved largely due to the developments obtained in the creation of composite products for the Buran reusable orbital spacecraft.

For the aviation industry

Despite the outstanding performance characteristics, close to the fifth generation, the Berkut was not adopted by the Russian Air Force and did not go into mass production.

As the former head of the Anti-Aircraft Missile Forces of the Special Forces Command of the Russian Air Force, reserve colonel Sergei Khatylev, noted in an interview with RT, the Berkut turned out to be too expensive and difficult to mass-produce a product.

“There was no necessary production base for the production of the Su-47.

In addition, other high-performance fighters based on the well-proven Su-27 were being developed at that time.

"Berkut" has remained in the history of our aviation as a bold and by no means ineffective experiment of the Sukhoi Design Bureau," Khatylev explained.

Rostec also does not consider the Su-47 an unsuccessful project.

The state corporation emphasized that within its framework, the domestic industry had developed a number of design solutions and launched the production of materials that were used to create new types of aircraft.

“For the first time in Russia, automated laying out of products, energy-saving composite equipment for autoclave molding of panels was mastered, tasks were solved for the automated formation of contours for cutting carbon fiber layers,” says Rostec in a comment to RT.

Also, as the corporation said, thanks to the Su-47 program, Russian specialists (in particular, the ORPE Technologiya team) developed a methodology for designing thick-walled asymmetrically reinforced wing panels and created a methodology for testing thick-walled witness samples.

“All this allowed ONPP Tekhnologiya to solve the problems of creating products from composite materials in the interests of the aviation industry,” Rostec explained.

"Full range of tasks"

The technological groundwork obtained in the framework of the Berkut project was useful not only for the development of the S-70.

Competencies in the Su-47, according to the state corporation, were implemented in two more large-scale aviation programs: in the creation of the fifth generation fighter PAK FA (Su-57) and the MS-21 passenger liner.

As experts interviewed by RT explained, in the Su-57 Berkut borrowed radar stealth technology, aerodynamic schemes of individual elements and digital computing systems.

Also, a significant amount of composite materials was integrated into the fifth generation machine.

Currently, the Su-57 is mass-produced at the Yu.A.

Gagarin in Komsomolsk-on-Amur.

As stated in the Rostec materials, the fifth-generation fighter has a durable and lightweight airframe, “which, together with other technical characteristics, provides the aircraft with excellent maneuverability.”

It is assumed that in the theater of operations, the Su-57 will give commands and interact with the Okhotnik UAV.

“When used together, unmanned aerial vehicles will solve a full range of tasks, working on air and ground targets under the command of a leading manned vehicle as part of network-centric interaction,” the UAC explained earlier.

Another aircraft that uses a significant amount of composite materials is the MS-21. 

True, some of the materials were supplied from abroad and in 2018 fell under sanctions.

The development of the missing components was taken up by teams from Moscow State University.

Lomonosov, "Rosatom" and a number of enterprises of the aviation industry of the Russian Federation.

On December 25, 2021, the first flight of the MS-21 took place with a wing made of domestic composites.

It is this aircraft that will be mass-produced at the Irkutsk Aviation Plant.  

In addition, Aerocomposite specialists have patented an infusion technology that allows creating complex large-sized surfaces from composites.

As a result, the mass of the wing is significantly reduced, the aerodynamic qualities are improved, and the fuel efficiency of the MS-21 is increased.

  • Production of Russian composite wing

  • RIA News

  • © Sergey Mamontov

As Sergei Khatylev noted, the replacement of metal products with composite analogues almost always gives a much-needed weight gain in aviation.

According to the expert, it was the Berkut fighter project that made it possible to realize the key advantages of using composites.

“The Su-47 program has clearly shown that the widespread use of composites can significantly improve the aerodynamics of an aircraft and reduce its radar signature.

Now the military and industrialists are trying to use composites as widely as possible.

Although, of course, not all metal parts need to be replaced - sometimes it makes sense to create new alloys, ”says Khatylev.

In an interview with RT, retired Major General Vladimir Popov, Honored Military Pilot of the Russian Federation, did not rule out that as composites and control systems are further improved, the military and industrialists of our country may return to creating manned and unmanned platforms with a reverse-swept wing.

“There is still a lot of work to be done on composites.

Nevertheless, in my opinion, the further development of composite production technologies will allow us to return to the creation of vehicles with a reverse swept wing.

In this context, the quality and availability of manufacturing technologies for various large-sized surfaces will be of great importance,” Popov summed up.