Another tall tale of Soviet engineering - there were similar stories around
Viktor Belenko's defection. He brought a MiG-25 along with him, thought to be a particularly high-performance modern fighter jet. When the CIA got their hands on it, they thought they were being
pranked - in some places, the damned thing had patches of
rust on it. With use of high-tech avionics and exotic composite materials soaring, the Soviets had nevertheless built the majority out of sheet metal. Steel, to be exact. Hand-welded and, in places,
riveted. The avionics used vacuum tubes.