'Magic Wings' helped revolutionize the Soviet Air Force.

The variable-geometry wing design addressed the technological challenges of the 1960s, revolutionizing Soviet aviation.

The unique feature of the retractable wing design.

On July 9, 1967, spectators at the Moscow Air Show witnessed for the first time the brand-new MiG-23 variable-geometry fighter jets and the Su-17. These were considered revolutionary third-generation fighters that shaped the Soviet aviation industry for decades to come, according to Sputnik.

"The variable-sweep wing principle applied to these two types of aircraft allowed Soviet designers to solve a number of difficult problems," said military analyst Andrei Kotz.

Previously, fighter aircraft only had two basic wing designs: straight wings and swept wings. Straight wings gave fighters a high lift coefficient, allowing pilots to take off easily, especially when the fighter was fully loaded with ammunition and fuel, as well as providing stability at subsonic speeds, but this design created significant drag when the aircraft reached supersonic speeds. Meanwhile, swept wings, angled at an angle to the aircraft's longitudinal axis, could help fighters achieve high speeds and better counter air turbulence, but their lift during takeoff was not as high.

The variable-sweep wing design, also known as the "magic wings," combined the advantages and eliminated the disadvantages of both principles, giving the MiG-23 and Su-17 many advantages and creating a breakthrough in the development of Soviet military aviation.

The variable-sweep wing design includes a hinged wing pivot, an inner wing section, a middle wing, and a rotation mechanism. During takeoff and landing, the pilot brings the wings to the fully extended position to maximize lift and shorten the takeoff and landing distance. While in flight, the wings gradually retract to reduce drag; the high speed of the fighter compensates for the lost lift due to the wings being swept back. When reaching supersonic speeds, the aircraft's wings are in their fully swept position.

The wing extension and retraction mechanism on the MiG-23 fighter jet. Photo: Wikipedia.

The drawback of this design is its large weight, making the fighter jet heavier than those with fixed wings. The complex structure of the variable-geometry wings also makes repair and maintenance difficult at makeshift airfields, which have less developed infrastructure than larger air bases.

However, the advantages of variable-geometry wings, along with many advanced aviation technologies at the time, compensated for these disadvantages.

"A fully armed MiG-23 weighing 20 tons only needs 450 meters of runway to take off, significantly shorter than a modern MiG-29 fighter of comparable weight. The maximum speed of the MiG-23 with its wings folded reaches 2,500 km/h, comparable to many modern fighter aircraft," expert Kotz asserted.

The MiG-23's high maneuverability, along with its advanced weaponry and electronics, helped Iraqi pilots win more than 30 dogfights against Iranian fighter jets between 1980 and 1988.The F-4, F-5, and F-14 are US-made aircraft in active service.The Iranian Air Force only won 9 battles at that time, even though the F-14 also possessed a variable-sweep wing design.

Kotz suggests that the US military also highly valued the MiG-23's design. In 1980, the US had approximately 12 MiG-23s in its inventory, which originated from the Egyptian Air Force.

American pilots and technicians thoroughly studied the MiG-23s. They disassembled them into the smallest possible pieces, then reassembled them and used them until 1988 for air combat training. American pilots praised the MiG-23's excellent acceleration, speed characteristics, and comfortable cockpit design. They considered it to be...The MiG-23 performed exceptionally well in close combat, but lagged behind in long-range duels.

The MiG-23 demonstrates variable-sweep and variable-sweep wing modes.

However, American technicians used the word "horrific" to describe the repair and maintenance of the MiG-23 fighter jet. This may be the reason for their high accident rate. Since entering service in 1970, more than 100 MiG-23s have crashed out of a total of 5,047 aircraft built.

For the Su-17 attack aircraft and its export variants, the variable-sweep wing design greatly assists in ground attack and infantry support missions. In addition to shortening takeoff and landing distances, the variable-sweep wings allow the Su-17 to attack ground targets at medium speeds, giving pilots more time to identify and accurately target their objectives.

This advantage significantly surpasses its predecessor, the Su-7B, which used a fixed-sweep wing design, had excessively high cruising speeds, and was ineffective for ground support.

The experience gained from the MiG-23 and Su-17 was a significant step forward for the Soviet and Russian aviation industry. They served as an important foundation for the Soviet Union's design of the MiG-27 attack aircraft, the Su-24 tactical bomber, the Tu-22M/M3 strategic bomber, and the Tu-160 strategic bomber. The Su-24, Tu-22M3, and Tu-160 are still in service with the Russian Air Force, directly participating in attacks against terrorist groups in Syria.

The variable-sweep wing mechanism of the Tu-160 bomber.

Today, variable-geometry wing technology is only suitable for bomber aircraft, where combat effectiveness largely depends on the amount of weaponry they can carry. Modern fighters like the Su-27, MiG-29, and their upgraded versions are built in a different direction, applying a blended wingbody design.) to form a unified raised surface.

The unibody design principle allowed Soviet and Russian aircraft designers to retain all the advantages of variable-sweep wings without complicating or increasing the weight of the airframe. This solution also enabled modern fighters to possess super-maneuverability and achieve supersonic speeds without the need for afterburners, a key requirement for fighter jets today.

The variable-sweep wing technology, developed more than 50 years ago on the MiG-23 and Su-17, successfully met the challenges of the 1960s and provided valuable insights for decades afterward for Soviet and Russian aircraft designers, Kotz concluded.

According to VNE