I've never seen one form out of clear air that quickly, as the pilot said local conditions were. I have flown a high performance jet alongside a rising cumulus and "raced" a column forming on the side that was rising quickly - it won, as in I ran out of climb capability before it did.
Whilst flying a sailplane I’ve seen a rotor cloud ( a kind turbulence associated with mountain wave soaring ) form in a fraction of a second. The first sign of it was a streak of cloud rising and curling over.
It was in front of me and I dived to get under it, passing through massive sink. Fortunately I found some ridge lift nearby and was able to make it back to safety.
Many years ago sailplane pilots flying in a contest near Marfa Texas were enjoying some strong updrafts in clear air and suddenly discovered they were in a coalescing strong tornado.
They don't usually form out of nowhere that quickly, but they grow upwards that quickly in case of unstable air. Unstable in this context is a function of the temperature gradient of the air mass with altitude, a bit simplified: If the temperature in an air mass is decreasing rapidly with altitude you have unstable air.
What happens is that some parcel of air is pushed upwards by something (e.g. surface heating, wind over surface features, a cold front moving underneath). That parcel of air will cool down due to decreasing air pressure. But if that cooling down happens at a slower rate than how much cooler the surrounding air is, it will still be warmer and keep accelerate upwards more. This can repeat itself to cause rapidly rising air.
If there is a lot of moisture in that air, the effect is worse. Because at some point that air will have cooled to the condensation level where relative humidity becomes 100%, then the moisture that was in the air will condensate and form clouds. That condensation process will release latent heat, helping the rising air parcel to keep rising further and faster.
And these are exactly that kind of conditions that cause big cumulonimbus clouds to form, which are dangerous even to airliners. Around the tropics, these clouds grow much higher than in more northern or southern latitudes.
Source: The theory class for my airline transport pilot license. A meteorologist would probably tell you this info in much more scientific terms :-)
Before anyone Monday-morning quarterbacks this - no, there wouldn't have been anything the pilot flying could feasibly have done to avert this outcome in the "one to three seconds" between becoming aware of the updraft and entering it.
Even if it were possible to turn sharply enough to avoid the column of rising air, a maneuver that hard would very likely cause as much havoc in the cabin as occurred in the actual event - as a passenger returning from the lav, for example, being thrown across the cabin would likely not be preferable to being thrown into the ceiling, and maybe less so because at least there's no one else to hit on the way to the ceiling. Leaving that aside, even making the attempt might be more dangerous than not, since if they'd tried to evade and failed, it would mean entering the updraft in a relatively unstable configuration and maybe stalling a wing.
Pretty sure we're armchair quarterbacking just agreeing here, but I would imagine any course of action other than smashing the seatbelt button would probably negatively influence the outcome. Turning will just increase baseline stress on the airframe so you might as well buckle up and get ready for any emergency adjustments after the turbulence is over.
Source: I've played some MS flight simulator and XP11 so I know a thing or two. About armchairs.
When they tell you to try to keep your seatbelts on at all times they are not kidding. I am sure some of the injuries were people like the quoted woman, people that had to take off their seatbelts to move around the cabin, but probably some of them were people that just unbuckled their seatbelts to feel more comfortable.
I have never understood the claim that seatbelts are uncomfortable. Are y’all cinching them down so hard it cuts off blood flow? At any reasonable tension, it exerts no more pressure than one’s underpants.
There’s this 4DX theater nearby, that has moving seats. The experience is quite fun, but let me tell you, I wish those seats had seatbelts. Not because I’m going flying, but it vibrates enough to keep me slipping out of my seat.
Yes, they are uncomfortable, if your butt tries to invade the next seat. If you sit properly, with a straight back and your bum at the end (or the start?) of your seat then you can sit like this for hours. Or until you start to lose your legs crammed in the back of next seat, but that is unavoidable for tall people.
People just don't know how to sit (properly), because nobody ever explained them nor they listened.
Having had a similar experience over the alps on air italia, this is why I never ever undo my belt unless I have to. The sign went on and 5 seconds later I felt myself physically leave the seat as we hit the worst turbulence I had ever felt.
I rediscovered my appreciation for the rosary that day.
I'll sometimes keep my belt loose when the seatbelt sign is off for an extended period. I know I won't leave my seat in case of really bad turbulence but worst case I might rise up a few inches. Obviously if the plane broke apart, a seatbelt probably isn't going to save me but leaving it loose is a nice compromise between safety and comfort.
Turbulence happens, and it’s often not possible to see it coming. Air is transparent after all. I’ve never been on a flight in the US where the preflight safety briefing didn’t say that seat belts should remain fastened when you’re in your seat. But I’ve also never been on one where i haven’t observed people being pretty damn casual about it when we’re at cruise. It is probably time to specifically add something about turbulence to the briefing requirements.
I think all airlines mention turbulence in the context of lap belts in their safety briefing. I know United does. Their passengers are no better behaved than what you've observed, though. Maybe there's a better way of getting the message across? Few people seem to pay any attention to the safety briefings, anyway. It's crazy.
Most commercial flights have flight attendants that already verify passengers are belted for takeoff and landing, they could just remind people during the flight as well, although I bet many would not be receptive to it.
Either you've never been on a plane before and are going to be nervous and likely listening to the safety briefing or you're an experienced flyer who's heard the speech many times and are going to do what you want. Air incidents are so rare that most people will never experience anything more than mild turbulence so they become complacent.
That's basically the problem. In the few incidents I've been in where the shit hit the fan, plenty of the grown adults around me screaming like children had to be in that group of "experienced" flyers, going by how many people I see totally oblivious during the briefings.
I don’t fly United much, but regardless, a mere mention of turbulence doesn’t really mean people understand what it means. Most people think “I almost spilled my drink” is severe turbulence.
What I more mean is that people should be made to understand that:
* severe turbulence can happen without warning during flight
* severe turbulence can launch you out of your seat if you aren’t strapped in
If you watch nearly any video of moderate to severe turbulence, people react like it’s a horror movie. People just don’t actually understand what turbulence can be.
Maybe it's because it's presented as a binary. If users want to be comfortable, it tends to equal 'remove belt'. But if users could be instructed to "if you must, loosen the belt" they'd at least have people keeping them on? A loose belt won't protect in a major event, but it should at least keep you in the seat for an unexpected drop.
this is a very strange description and hard to believe.
like, some little white fluffy cloud, shaped like stuffed teddy doggo, is just sitting there, and then decides to shoot upwards at lightning speed for no or some reason, like a UFO?
ok. strange things happen. but i'd def be drug-testing the pilot.
also, the timelines seem weird. like when people who get into car collisions are like, 'they came out of nowhere, so i honked my horn, then i turned my wheel, and then' -- you did what?
you honked your horn? instead of taking evasive action? that was the first thing you thought to do? yell at some driver for attempting to kill you when you could have taken evasive action instead? you thought, hey, let me take the next two or three seconds to honk my horn, knowing that impact is certain within two to three seconds if i don't take immediate evasive action? maybe you were worried about your insurance instead of living? i get it, in america, even minor inicents can result in a literal death spiral, but this whole incident sounds off. maybe it's just the description. or maybe this is the AP Pilots or Meteorology feed.
In a glider being towed through rotor to reach wave, you learn to tighten your shoulder straps to keep your head from bouncing off the canopy.
One of my batteries disconnected in a big bump.
In airliners it happens that people bounce off the ceiling and crash back down. Even if you have loosened your seatbelt for comfort, it will keep you from bouncing off the ceiling.
0g will have loose objects floating. -.25g will have them on the way to the ceiling. The autopilot will react quickly to restore 1g and bring everything and everybody back down.
41 comments
[ 2.3 ms ] story [ 94.2 ms ] threadIt was in front of me and I dived to get under it, passing through massive sink. Fortunately I found some ridge lift nearby and was able to make it back to safety.
Many years ago sailplane pilots flying in a contest near Marfa Texas were enjoying some strong updrafts in clear air and suddenly discovered they were in a coalescing strong tornado.
Plane condensation trails are a form of clouds.
What happens is that some parcel of air is pushed upwards by something (e.g. surface heating, wind over surface features, a cold front moving underneath). That parcel of air will cool down due to decreasing air pressure. But if that cooling down happens at a slower rate than how much cooler the surrounding air is, it will still be warmer and keep accelerate upwards more. This can repeat itself to cause rapidly rising air.
If there is a lot of moisture in that air, the effect is worse. Because at some point that air will have cooled to the condensation level where relative humidity becomes 100%, then the moisture that was in the air will condensate and form clouds. That condensation process will release latent heat, helping the rising air parcel to keep rising further and faster.
And these are exactly that kind of conditions that cause big cumulonimbus clouds to form, which are dangerous even to airliners. Around the tropics, these clouds grow much higher than in more northern or southern latitudes.
Source: The theory class for my airline transport pilot license. A meteorologist would probably tell you this info in much more scientific terms :-)
Even if it were possible to turn sharply enough to avoid the column of rising air, a maneuver that hard would very likely cause as much havoc in the cabin as occurred in the actual event - as a passenger returning from the lav, for example, being thrown across the cabin would likely not be preferable to being thrown into the ceiling, and maybe less so because at least there's no one else to hit on the way to the ceiling. Leaving that aside, even making the attempt might be more dangerous than not, since if they'd tried to evade and failed, it would mean entering the updraft in a relatively unstable configuration and maybe stalling a wing.
Source: I've played some MS flight simulator and XP11 so I know a thing or two. About armchairs.
(I'm neither large not squirmy, so seatbelts don't bother me in the slightest.)
People just don't know how to sit (properly), because nobody ever explained them nor they listened.
I rediscovered my appreciation for the rosary that day.
https://www.theholyrosary.org/howtoprayrosary (for example) was an interesting read, as was your comment.
What I more mean is that people should be made to understand that:
* severe turbulence can happen without warning during flight
* severe turbulence can launch you out of your seat if you aren’t strapped in
If you watch nearly any video of moderate to severe turbulence, people react like it’s a horror movie. People just don’t actually understand what turbulence can be.
like, some little white fluffy cloud, shaped like stuffed teddy doggo, is just sitting there, and then decides to shoot upwards at lightning speed for no or some reason, like a UFO?
ok. strange things happen. but i'd def be drug-testing the pilot.
also, the timelines seem weird. like when people who get into car collisions are like, 'they came out of nowhere, so i honked my horn, then i turned my wheel, and then' -- you did what?
you honked your horn? instead of taking evasive action? that was the first thing you thought to do? yell at some driver for attempting to kill you when you could have taken evasive action instead? you thought, hey, let me take the next two or three seconds to honk my horn, knowing that impact is certain within two to three seconds if i don't take immediate evasive action? maybe you were worried about your insurance instead of living? i get it, in america, even minor inicents can result in a literal death spiral, but this whole incident sounds off. maybe it's just the description. or maybe this is the AP Pilots or Meteorology feed.
One of my batteries disconnected in a big bump.
In airliners it happens that people bounce off the ceiling and crash back down. Even if you have loosened your seatbelt for comfort, it will keep you from bouncing off the ceiling.
0g will have loose objects floating. -.25g will have them on the way to the ceiling. The autopilot will react quickly to restore 1g and bring everything and everybody back down.