At Randall Munroe's What If? blog, where he researches the oddest questions from readers, he tells us what would happen to a typical airplane if it were flown on other planets and the larger moons in the solar system. For each of the nine heavenly bodies with enough atmosphere to even consider flight, Munroe looks at the pure physics of the flight, and only afterward considers the effects of other conditions, such as temperatures and poisonous gasses. Take Venus, for example:
Unfortunately, X-Plane is not capable of simulating the hellish environment near the surface of Venus. But physics calculations give us an idea of what flight there would be like. The upshot is: Your plane would fly pretty well, except it would be on fire the whole time, and then it would stop flying, and then stop being a plane.
The atmosphere on Venus is over 60 times denser than Earth’s, which is thick enough that a Cessna moving at running speed would rise into the air. Unfortunately, the air it’s rising into is hot enough to melt lead. The paint would start melting off in seconds, the plane’s components would fail rapidly, and the plane would glide gently into the ground as it came apart under the heat stress.
A much better bet would be to fly above the clouds. While Venus’s surface is awful, its upper atmosphere is surprisingly Earthlike. 55 kilometers up, a human could survive with an oxygen mask and a protective wetsuit; the air is room temperature and the pressure is similar to that on Earth mountains. You need the wetsuit, though, to protect you from the sulfuric acid. (I’m not selling this well, am I?)
You'll want to read all of them. Link