Why Are There No New Swing Wing Designs?

[Delta Force]

In the 1960s swing wings seemed to have been proposed for just about every type of aircraft, from bombers and fighters through to supersonic airliners. The Panavia Tornado and Tu-160 were some of the last aircraft designed with swing wings. With the current emphasis on stealth and long loiter times it makes sense that swing wings are no longer proposed, but they largely stopped being proposed in the mid-1970s. Is it simply that by the mid-1970s the roles where swing wings are particularly well suited were already filled with new aircraft (thus no need to design new ones) or did the more efficient engines and computer aided flying make the advantages smaller? The mid-1970s also seems to have been the time in which designs were optimized for the transonic speeds most aircraft spend their time at. Were aircraft simply aerodynamically optimized for transonic flight profiles instead of supersonic speeds? From the mid-1970s onwards sustained supersonic performance seems to have gone out of vogue in favor of transonic cruise and provision for occasional supersonic dashes.

 

[Stargazer]

If by "swing wing" you mean wings that retract rearwards for increased velocity, there seems to be a shortage of such designs indeed.

But if you give the term a broader meaning, I can think of the Northrop "Switchblade" patent which had wings folding forward.

 

[Hanse]

Well, by their nature, swing wing designs are, structurally speaking, more inefficient than fixed wing designs. Added to that, they require some quite specialist materials and machining operations at forging/billet volumes not normally seen. Therefore, they also tend to be more expensive and harder to make than fixed wing designs.

Furthermore, swing wing designs are likely to be more difficult to design for low observability due to the requirement for extra (and large) panel gaps.

Swing wing designs were initially considered for their good performance across the range of speeds that aircraft were to operate at. These days I think aerodynamic design and engine technology have moved on to such an extent that these factors can now be subsumed in to a fixed wing design.

Had the USN not cancelled the NATF (naval F-22) it would have been a swing-wing design. Same with the AF/X after that.