What would happen if everyone on an airplane jumped while in flight?

Answer 1

You'd effect a "load shift" within the plane, pretty much identical to what happens when cargo shift's within an airplane. First, we'd see the load (passengers of course) pressing the plane DOWN, but the actual amount of energy involved comes only from the passengers leg muscles -- not enough to generate even 1g, and planes are built to handle a LOT more G's than that. The fall to the cabin floor would be even less eventful, as everyone jumps more or less than everyone else. Assuming everyone jumped at the same time, you see a load shift that was peak. Everyone falling back to the cabin floor though will happen at different times, and thus the overall G-force of the fall is spread across time -- and will not spike all that much. So basically -- nothing of interest would happen. I think the greatest risk would be the flooring panels in the cabin. But let's toss in a little Tesla. If they all jumped over and over again in unison, at a frequency harmonic to something in the plane's structure, and if that jumping could gradually increase the amplitude of that harmonic, you might eventually see structural failure. This is pretty far fetched as planes run into this type of problem frequently and are built to avoid it. But it's remotely possible. However, the most grave scenario is if you get everyone to jump up and down at the same time over and over again, while singing the Starland Vocal Band's song, "Afternoon Delight" in tempo....