During a visit to Boeing, Soviet scientists secretly applied adhesive to the bottom of their shoes in order to covertly collect metal samples from the floor.
The SR-71 Blackbird, the fastest plane ever built, would go so fast its outside temperature would reach 572 F (300C). It had to be built with components that could grow as they heated. Because of this, the jet would leak fuel until it got hot.
The Soviet Tu4 was a reversed-engineered copy of the US B29 bomber. Copied to such detail that every Tu4 had a rivet hole in one wing exactly where an unknown Boeing engineer mistakenly drilled it in the B29 used as a template.
In 1918 the U.S. developed and successfully flew a legitimate unmanned aerial vehicle (UAV), making it one of the first.
A McDonnell Douglas F-15 once shot down a satellite.