Single versus twin engines for naval F-35 variants

Should the naval F-35 variants have used two engines?

A second engine adds redundancy, but it would make the F-35B much heavier and split the naval versions further from the single-engined land-based design.

The exchange asks whether a naval strike fighter should favour two engines for redundancy. The single-engined Harrier made the arrangement workable, and the F-35's engine is judged more reliable than the earlier aircraft's powerplant. A twin-engined F-35B would become much heavier, which is particularly costly for short take-off and vertical landing. A separate twin-engined carrier variant could avoid that vertical-flight penalty but would diverge sharply from the land-based aircraft and its role as an F-16 replacement. The design choice therefore trades engine redundancy against aircraft weight, STOVL performance, and commonality across the programme. Adding a second engine changes the whole aircraft rather than supplying free safety.