Wings Over Hooterville - S2-E1
Factual error: In a flashback scene, Oliver is hanging from a tree after getting shot down in WWII. They ask him where he is from, and he says the US Air Force. The US Air Force wasn't formed till 1947. During WWII, it was the Air Corps.
Jeannie, the Hip Hippie - S3-E6
Factual error: At the end of the episode, Major Nelson leaves his Cocoa Beach, Florida, house and drives down the street. Behind the house at the end of the street (which is the home used for the Stephens family on "Bewitched"), there is a mountain. There are no mountains in Cocoa Beach.
Factual error: The Robinsons exceeded the speed of light due to impurities in chemical rocket fuel. No chemical rocket fuel comes remotely close to the energy content needed to even approach the speed of light. That would require exotic fuels like antimatter. By Einstein's theory of Special Relativity it is impossible to exceed the speed of light with any form of rocket propulsion. Faster than light travel and time travel might be possible with the warped spacetime of Einstein's general theory of relativity and phenomena such as wormholes. For plausibility the opening scene should have been an encounter with a wormhole.