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I was on a flight recently that went through turbulence that had me convinced I was about to die. To be clear, I love flying. I find the sound of a pressurized air plane cabin to be very relaxing. I like to look out the window whenever possible, even during turbulence and it takes a lot to rattle me.

This was different.

The plane shook and bounced around in ways I had never felt before. It had bounced left and right and shuddered in ways that at first I just thought was sort of scary, but that's all. Suddenly, it felt like we were falling. It felt like we fell for a solid two whole seconds. I was thoroughly shaken.

The pilot got on the speaker and said a lot of things about being seated and putting on our seat belts, he said "safe" and "safety" quite a few times, and after the turbulence, he got on the speaker again and said he was communicating with someone to find a safe route and that we would be delayed. It felt like we were in a really dangerous storm or something.

Anyway, I'm curious if my fears were anywhere near reality. Did we really fall for those 2 whole seconds? How far did we probably fall? Sort of morbidly curious.

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    $\begingroup$ which flight was it? tracking it on flightradar or similar will tell you if it really was dangerous $\endgroup$
    – EarlGrey
    Sep 27, 2023 at 9:00
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    $\begingroup$ Re, "...safe...safety..." Every so often you hear of people who were injured on commercial flights because they didn't put their seat belts on when they were told to do, and they hit their heads on the ceiling. (Or, hit other body parts on other things. I remember reading one account in the news that quoted a passenger. "Yeah!" he said, "People were just kind of flying all around the cabin.") $\endgroup$ Sep 27, 2023 at 17:01
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    $\begingroup$ @SolomonSlow Yes, that's exactly it. The safety concern is from passengers going flying into ceilings or, more likely, stuff around the cabin (such as service items or passengers' items) going flying into passengers and cabin crew. The airplane is not going to be flying into any turbulence that would actually be dangerous to the airplane itself. Unless you do something really dumb like flying straight into a thunderstorm cell (which sane pilots would not do,) turbulence is not dangerous to airliners in cruise phase. Of course, it can be dangerous when very near the ground. $\endgroup$
    – reirab
    Sep 27, 2023 at 18:39
  • $\begingroup$ Other than confusion, what would be lost if you dropped all before 'Suddenly, it felt like we were falling…'? $\endgroup$ Sep 27, 2023 at 20:06
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    $\begingroup$ @SolomonSlow: Or worse, the reckless people fall onto other people and injure people who did follow safety instructions. $\endgroup$ Sep 28, 2023 at 13:03

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It's possible. Two seconds of true freefall corresponds to about 60 feet of altitude loss. This is by no means unheard of- severe turbulence can sometimes result in hundreds of feet of altitude loss!

Most likely it was not true freefall, and it was somewhat less than two seconds. 10-20 feet of altitude drop is not rare at all and it feels like a lot more than it sounds like.

It's unlikely the plane was in any danger. While truly extreme turbulence could destroy an airliner, what you've described is nowhere close to that level. You were likely at some small risk of injury if some poorly-secured baggage were to fall on you.

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    $\begingroup$ An airplane is the only place I have ever dropped 20 feet. I enjoy turbulence but that sounds like a long way to me. $\endgroup$ Sep 27, 2023 at 10:58
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    $\begingroup$ @AnonymousPhysicist For comparison, the drop on Disney World's Tower of Terror ride is 130 feet. Almost any roller coaster will have significantly more than 20' drops. $\endgroup$
    – reirab
    Sep 27, 2023 at 15:39
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    $\begingroup$ @AnonymousPhysicist It's not the drop that kills you, but the sudden stop at the end, and planes don't suddenly stop unless they crash. Nor do rollercoasters. $\endgroup$
    – user253751
    Sep 27, 2023 at 21:10
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    $\begingroup$ One time I rode through moderate turbulence and was fearful when seeing the wings bend and bounce. Later I learned that the wings are engineered and tested for extreme bending, far more than what I saw on that ride: youtube.com/watch?v=B74_w3Ar9nI $\endgroup$
    – Nayuki
    Sep 28, 2023 at 18:18
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    $\begingroup$ Has anyone ever stopped to think that it could just have been the "simulator effect"? Cabin simulators move in a way that makes us believe we are in one type of movement, when in fact it is another. Cockpit simulators don't fall. A sharp downward acceleration followed by a very gentle stop will make you think you are still falling. As long as you don't look outside, you will believe this lie. If you are really interested in knowing how you will die on a flight, take flight instruments with you. $\endgroup$
    – Magno C
    Sep 29, 2023 at 12:22
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It is even possible the plane was not descending at all. Unless I am mistaken, an updraft can cause the plane to accelerate upwards and, if the upwards acceleration ends abruptly, it can feel as if you are falling even though you are really just moving upwards at a decreasing rate. If you put a pebble in a plastic bottle and toss the bottle in the air, you will see the pebble in free fall on the way up as well as down.

This is not to say turbulence is harmless. They want you to wear your seatbelts for a reason. The point is that the sensation of falling can be deceptive about what direction the plane is actually moving.

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  • $\begingroup$ "The plane was not descending" gives no indication of the risk of injury. A passenger who is not wearing a seatbelt could still hit their head on the ceiling when the plane is ascending but accelerating downwards. $\endgroup$ Sep 27, 2023 at 10:55
  • $\begingroup$ Added a paragraph. $\endgroup$ Sep 27, 2023 at 12:52
  • $\begingroup$ @AnonymousPhysicist True enough; but because the OP is wondering specifically about falling, with the implication that they feared they might fall too far (even if a simple back-of-the-envelope calculation shows that that would need more than 2 seconds): Falling is typically more dangerous for an airplane than climbing. $\endgroup$ Sep 28, 2023 at 1:04
  • $\begingroup$ Just to be safe: please do not toss any bottle with pebbles inside a airplane. Especially during turbulence. $\endgroup$
    – Magno C
    Sep 29, 2023 at 12:19
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There are (rare) circumstances of an airline type airplane experiencing extreme/severe turbulence where unbuckled passengers and cabin crew have been lifted off of their seat or feet and hit the cabin ceiling. These are exceedingly rare events that sometimes result in a loss of altitude of more than a thousand feet. Again this type of event is very rare.

In my experience, what a passenger my interpret as a long vertical drop in altitude during moderate (as you have described) turbulence would have a resultant altitude loss that would rarely exceed 100 feet. Typically it's less than 100 feet and less than 2 seconds.

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  • $\begingroup$ It is not exceedingly rare. It is the most common cause of injury on passenger flights. The cabin crew is in bigger danger for obvious reasons. Many cases don't get recorded because they result in less than 48 hours hospitalization. $\endgroup$ Sep 27, 2023 at 19:10
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    $\begingroup$ @VladimirFГероямслава I guess it depends on what your definition of "exceedingly rare" is. There are thousands of passenger flights world-wide per day (maybe as many as 90,000). Experiencing "severe" or "extreme" turbulence where the cabin crew and/or passengers are lifted off of their seats or feet and hit the cabin ceiling would be, in my opinion, categorized as "exceedingly rare." $\endgroup$
    – user22445
    Sep 27, 2023 at 19:39
  • $\begingroup$ As I wrote, it is around 40% of all injuries. And only of those that count - that is more than 2 days in the hospital. Tens of injuries per year just in the US. Reporting smaller injuries is not mandatory. If everyone thinks that means exceedingly rare, so be it, I will wear my seatbelt when seated. $\endgroup$ Sep 29, 2023 at 18:00
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Paragliding pilot here.

A feeling of falling down or rising up is associated with vertical acceleration rather than velocity; so you might actually be losing altitude for two seconds or might have been in a strong updraft a second earlier and started to fall out of it.

It's nigh on impossible to calculate how much altitude the plane has lost in those two seconds, because you might be faster or slower than a free falling object due to vertical movement of the air surrounding the plane and the wings. If it's any reference, a free falling object would lose about 20m in two seconds, source here. I'm afraid it's also quite difficult to trust your senses and the perception of time at that moment.

What really matters is that very rarely do aircraft go through extreme turbulence and it's safer to keep the belt on throughout your flight if possible. As far as I know, aircraft pilots are benefitting from shared information with each other and control towers and can avoid turbulent areas as long as they're informed but every now and then a plane will get caught with no indication and no possibility of avoiding turbulence.

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That sounds like the aircraft entered an area of moderate, possibly even severe, clear air turbulence that was concerning enough that even the flight crew wanted to divert from. Yes, there is a real hazard there. Fortunately, airplanes flying today are pretty darn well built and can take quite a beating from turbulence before they cry foul. That doesn’t mean they’re indestructible but the danger areas are far beyond what you might think they are.

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    $\begingroup$ The main reason why the flight crew wants to escape from turbulence is passenger comfort, and the danger of spilled coffee in the flight deck. $\endgroup$
    – YPOC
    Sep 27, 2023 at 8:33
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    $\begingroup$ SEVERE turbulence can accelerate a plane downwards at more than 1G, meaning anything not belted down "falls" upwards relative to the plane. I read that on one occasion a passenger's head went through the luggage bin above him, which (fatally) broke his neck. This degree of turbulence is very rare, but a good reason to keep that belt on! $\endgroup$
    – nigel222
    Sep 27, 2023 at 8:58
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    $\begingroup$ ¨@nigel222 abcnews.go.com/Health/story?id=7391144&page=1 paralyzed because of turbulence (or, cinically said: because of not following flight-crew instructions ... sometimes we overblow our concerns about peeing&co, there is a reason why one should have always a complete clothes change in one's own handbag, a part from the possibility that the plane is diverted from sunny Los Angeles to the artic swissinfo.ch/eng/society/… ) $\endgroup$
    – EarlGrey
    Sep 27, 2023 at 9:03
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    $\begingroup$ Not necessarily true $\endgroup$ Sep 27, 2023 at 15:19
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    $\begingroup$ @RuthLessPirate: not at all. Airliners envelope is always within -2/+5 g, and even less than that. Humans can survive twice that sustained, and much more on impact. $\endgroup$ Sep 28, 2023 at 6:00

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