The discussion on the "slip-up" regarding F-35 stealth capabilities got me thinking about the concept of "stealth generation" similar to the concept used to describe general fighter capability. Just something to help discern between the general "stealthiness" of various aircraft. I couldn't really find a clear guide here on ATS, so I don't really know if the idea of what firmly defines a 1st generation stealth aircraft vs 2nd, 3rd or 4th has been established already . With that in mind, what does define 1st gen stealth? U2, SR-71, B-1 - since stealth materials were applied, but they were not designed for "all-aspect" stealth? maybe 2nd gen would be the F-117 (and Lampyridae), due to a true all aspect stealth design relying on faceting? 3rd gen might be the B-2 - all aspect not relying faceting, 4th gen might add supercruise and maybe "active" stealth.... ideas anyone?