Clouds form that quickly?
NTSB: Cloud shot up vertically in front of plane before turbulence
11–20 of 42 posts
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#12Turbulence 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 abou…
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#13Clouds form that quickly?
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.
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#14Clouds form that quickly?
Plane condensation trails are a form of clouds.
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#15Having 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.
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#16Turbulence 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 abou…
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.
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#17Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#18Turbulence 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 abou…
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.
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#19Clouds form that quickly?
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 :-)
Re: NTSB: Cloud shot up vertically in front of plane before turbulence
#20Before 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 eve…
Source: I've played some MS flight simulator and XP11 so I know a thing or two. About armchairs.