Factual error: When Shawn is talking to Belle over the phone, the Eiffel Tower can be seen outside her window, yet, she's supposed to be in Milan, Italy.
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.
The Night of the Wolf - S2-E27
Factual error: Several airplane contrails are visible in the sky as West gallops his horse to Stefan's coronation.
Factual error: We see how the accident-prone Wilton Parmenter was a soldier at Appotomatox during the Civil War when he sneezed. Union soldiers mistook his sneezing for a call to regroup and charge, winning the battle. Wilton Parmenter was awarded the Medal Of Honour. Accident-prone, even in his moment of glory, when the medal was pinned on Wilton's chest it pierced his skin, drawing blood. Wilton was therefore awarded the Purple Heart, becoming "the only soldier in history to get a medal for getting a medal." This was not possible, for the "Purple Heart" (or "Badge Of Military Merit", to use its proper title) awarded to US soldiers wounded in action, was only instituted in 1932. (Before somebody corrects me, George Washington did institute the award for some distinguished combatants during the War Of Independence, but it was never awarded during the nineteenth century, and revived in 1932).
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.
Last Train to the Fair - S1-E30
Factual error: At the end of the episode as the train heads towards Sacramento, above in the sky are jet vapor trails streaking across the sky.
Closely Watched Planes - S4-E3
Factual error: If there really was a hatch leading into mid-air in the airplane bathroom, instead of being soundless like shown, it would be incredibly loud and Max would have noticed. Also, the sudden pressure change would have sucked him out no matter what he did to stop it.
Factual error: At the start of this episode you see the terminal at Washington Reagan National Airport, but when Mr. Haslett picks up his ticket you hear an announcement stating it is the Seattle, Washington Airport. (00:00:20)
Sucker Bait - S1-E7
Factual error: It is quite true that atoms that do not occur naturally are bad for humans. However, in a space age as this story's, that would apply to most or even all planets. It would be a well known risk that didn't require an abnormal specialist to diagnose. (This fact rarely figures in other SF, because it would severely limit most stories).
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.