[HN Gopher] NTSB: Cloud shot up vertically in front of plane bef...
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NTSB: Cloud shot up vertically in front of plane before turbulence
Author : geox
Score : 43 points
Date : 2023-01-14 16:24 UTC (6 hours ago)
(HTM) web link (apnews.com)
(TXT) w3m dump (apnews.com)
| kjrose wrote:
| 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.
| InCityDreams wrote:
| Not being Catholic, I looked up 'the rosary'. Which lasted
| longer...it, or the turbulence?
|
| https://www.theholyrosary.org/howtoprayrosary (for example) was
| an interesting read, as was your comment.
| KMag wrote:
| At least in my experience, if I listen closely to the standard
| announcements, this is the explicit recommendation from the
| pilot/cabin crew as well.
| wildzzz wrote:
| 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.
| kube-system wrote:
| The plane isn't going to break apart due to turbulence.
| Airliners are all designed to withstand 150% of the most
| severe turbulence.
| kyleee wrote:
| Clouds form that quickly?
| t0mas88 wrote:
| 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 :-)
| xeromal wrote:
| It reads like the clouds moved that quickly which would
| indicate some kind of crazy updraft.
| thrill wrote:
| 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.
| cinntaile wrote:
| What was the result? You couldn't outrun the turbulence?
| thrill wrote:
| Oh, I was solo in a jet trainer in a restricted (for me)
| area, so I just sliced off to the outside of the cloud with
| a big smile on my face.
| no-s wrote:
| 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.
| 323 wrote:
| Not in this case, but they can.
|
| Plane condensation trails are a form of clouds.
| Beldin wrote:
| The exhaust of a plane isn't clean air though - which is why
| the condensation forms.
| kube-system wrote:
| You can see air moving if opaque particles (eg. a cloud) are in
| the moving stream of air. Otherwise you don't see anything.
| dilyevsky wrote:
| Everyone onboard got six flags experience without the lines
| hristov wrote:
| 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.
| moistly wrote:
| 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.
| petre wrote:
| I am unconfortable without my seatbelt in the car. The same
| goes on an airplane. It's only a matter of getting used to
| it.
| kube-system wrote:
| 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.
| alamortsubite wrote:
| 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.
| wildzzz wrote:
| 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.
| alamortsubite wrote:
| 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.
| kube-system wrote:
| 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.
| interestica wrote:
| 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.
| ALittleLight wrote:
| Could just make an occupied seat's belt chime every n seconds
| it isn't buckled.
| gryn wrote:
| those people would just buckle the seat-belt and sit on it
| like they do in cars.
| kube-system wrote:
| 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.
| BatFastard wrote:
| Like a cloud created by a UAP?
| [deleted]
| throwanem wrote:
| 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.
| andrewstuart2 wrote:
| 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.
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(page generated 2023-01-14 23:02 UTC)