TIL the first supersonic airliner was not the Concorde or Tu-144, but a DC-8. During a test flight in 1961 it achieved supersonic speed for 16 seconds while in a dive. Accompanying the airliner in a chase plane was Chuck Yeager, the first pilot to break the sound barrier.

Gladly! The basic idea is that depending on what (usually extreme) maneuver an aircraft is performing, it’ll have a different effect on the people in the cabin.

For example, an extreme dive at high speeds would cause “negative G’s,” which would cause a feeling of weightlessness for people in the cabin, if it’s extreme enough it could cause people to actually be lifted out of their seats if they’re not strapped in. In the opposite, an extreme climb, you’d experience “positive G’s,” which would make you feel like you were being forced down into your seat, sometimes making it difficult to move at all.

Needless to say, these conditions aren’t ideal for an average person on a commercial flight, which is why maneuvers on commercial flights are very gentle and gradual (when possible) to avoid it altogether. Combat pilots experience these circumstances when maneuvering their aircraft, but they’re specifically trained to do so in combat scenarios.

Someone with more hands-on piloting experience or a better grasp of physics could definitely provide a better explanation for exactly how and why this happens, as well as the terminology that goes with it, but like I said that’s the basic gist of it, hope that’s helpful!

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