As the US Air Force develops its NGAD 6th-gen fighter, speculation is already mounting about what a 7th-generation aircraft ...

See the evolution of Boeing's design of the F-47, a sixth-generation stealth fighter jet, compared with competing NGAD concepts from Lockheed and others.

Lockheed has been a leader in stealth aircraft, playing a prominent role in both US fifth-gen fighters. It won't be building the first sixth-gen jet.