Several projects beyond the B-52, the Convair B-58 Hustler and North American XB-70 Valkyrie, had either been aborted or proved disappointing in light of changing requirements, which left the older B-52 as the main bomber as opposed to the planned successive aircraft models.
Adskillige projekter efter B-52, Convair B-58 Hustler og North American XB-70 Valkyrie, var enten blevet opgivet eller viste sig skuffende i lyset af ændrede behov, hvilket betød at B-52 forblev det vigtigste bombefly frem for de påtænkte nye typer.