America’s Best Cold War Jets All Had One Design Feature
But the variable-sweep wing design seems to have gone out of fashion most recently.
As the name suggests, “variable-sweep” wings are aircraft wings that can be adjusted to different degrees of sweep—rotating outward when the aircraft is traveling at lower speeds, such as during takeoff and landing, and folding inward at supersonic speed.
The benefits of variable-sweep wings are roughly what you’d expect: they give a plane greater variety. Several prominent military aircraft have incorporated variable-sweep wings. The first to be put into production was the F-111 Aardvark. But the F-111 wasn’t the first aircraft to feature the design, and wouldn’t be the last.
Sweeping the Wing
Different wing configurations have different advantages and disadvantages. For example, wings that are swept back and held flush with the fuselage of an aircraft are wonderful for enabling speed: most supersonic aircraft feature a fixed swept wing design.
But while speed is increased, the swept wing does carry certain performance tradeoffs. Most notably, the stall speed is increased, meaning that the aircraft needs to keep going fast to avoid a stall. Doing this is not always convenient, of course; having to land at high speeds can be very dangerous, and requires longer runways—which is especially problematic for carrier-based aircraft operating with very finite runway lengths. Other aircraft have mission profiles that benefit from slower speeds, like the A-10 Warthog—which is tasked with providing close air support to troops on the ground, and thus required to loiter in a given area for some time.
With a variable-sweep wing, however, an aircraft can modify its wing sweep based on the needs of the moment—wings straight for landing, wings swept for supersonic flight, and all variety in between. Of course, incorporating the mechanics for variable-sweep wings are heavy, complex, and expensive—which is why you’d be hard pressed to find variable-swept wings outside of the military realm.
But within the military realm, variable-sweep wings have been successful, and relatively common, if not fully standard.
Following the Aardvark
The first variable-sweep wing aircraft ever put into production was the F-111 Aardvark, a supersonic interdictor that served with the U.S. Air Force and the Royal Australian Air Force. But the F-111 was not the first variable-sweep wing aircraft ever built. That distinction belongs to the Westland-Hill Pterodactyl, a series of experimental tailless aircraft designed in the 1920s and 1930s.
The most famous variable-sweep wing aircraft, undoubtedly, is the F-14 Tomcat, which owes its fame to the Top Gun film series. Featured prominently in 1986’s highest grossing film—and for a scene-stealing cameo in the 2022 sequel—the F-14 was the Navy’s workhorse fighter through much of the 1970s and 1980s.
Across the pond, the Soviets were busy with their own variable-swept wing designs, too. Examples include the MiG-23, MiG-27, and Tu-22. The MiG-23 was widely produced, with over 5,000 units made, and exported internationally to Syria, India, and Bulgaria. The MiG-27 was built as an upgraded version of the MiG-23, but optimized for air-to-ground combat.
The variable-sweep wing design seems to have gone out of fashion most recently. Indeed, the concept appears to have peaked during the second half of the Cold War. Today’s newer aircraft on both sides of the old Iron Curtain—including America’s F-22 and F-35, Russia’s Su-57, and China’s J-20—invariably do not feature variable-swept wings.
About the Author: Harrison Kass
Harrison Kass is a senior defense and national security writer with over 1,000 total pieces on issues involving global affairs. An attorney, pilot, guitarist, and minor pro hockey player, Harrison joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. Harrison listens to Dokken.
Image: Shutterstock.