The Sukhoi T-4, or "Aircraft 100", or "Project 100", or "Sotka" was a Soviet high-speed reconnaissance, anti-ship and strategic bomber aircraft that did not proceed beyond the prototype stage. It is sometimes called the Su-100.

The North American Aviation XB-70 Valkyrie is a retired prototype version of the planned B-70 nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed in the late 1950s by North American Aviation (NAA) to replace the aging B-52 Stratofortress and B-58 Hustler, the six-engined, delta-winged Valkyrie could cruise for thousands of miles at Mach 3+ while flying at 70,000 feet (21,000 m).