NTSB Safety Alert - Dust Devils: Silent Sky Snares
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- Опубликовано: 24 мар 2024
- Dust devils, while often considered a harmless phenomenon, present significant hazards to aviation and have been present in more than 170 accidents the National Transportation Safety Board has investigated since 1982. Learn how to detect and avoid dust devils in this video and the full safety alert at www.ntsb.gov/air.
Fly Safe!
Hello!
Fly safe!
Dust devils are not a joke, some of them can be as strong as small tornadoes. I've seen them blow RVs over, and been blown down by them too. They can make a tractor-trailer fishtail or tip if it's lightly loaded or empty. They can kick up enough dust to suddenly cut visibility to essentially zero for ten or fifteen seconds.
They're fascinating -- even kind of entertaining to watch in some places where you might see a dozen of them at once in different stages of development -- but also something to be wary of.
In May 2009 saw multiple stronger ones which sounded like overflying passenger jet in one day in pretty much yard of home farm.
Saw one of them actually from 20 feet distance.
First noticed it from dust on ground and empty plastick sack of 650kg fertilizer package starting to move on ground at edge of vision and then noticed dust devil starting to "pick up speed" 15 feet away.
Then I just watched that sack get pulled all the way in and shoot up to maybe 200 feet altitude in few seconds.
Visible vortex of that dust devil itself was very condensed with 5-6 ft diameter and it had sharp edged denser "core" maybe 2 ft wide.
Dust devil lasted maybe about one minute and plastick sack landed ~300ft from "take off" location.
In month and half there should good conditions for them with sun heating ground surface very strongly, but air often being pretty cold from northern wind bringing even polar air.
I live way up north, and I've only seen them them once in my life, driving through TX, and they were everywhere! A bunch of young kids were running through them, playing. Clumps of cut hay or something similar were being pulled up. It was a really cool sight! But yeah, I wouldn't want to fly through or over one!
Glider pilots know a lot about dust devils. One thing to note is that they exist invisibly without dust anywhere on a convective afternoon
@FishingPlanetMobile64 yes, without dust there can be no dust devils. But the convective vortexes and their effects exist nonetheless
I remember driving around in the San Luis valley in Southern Colorado one day, hot, fairly still air, cloud free. I had once thought they were near ground phenomena. I had seen them appear as towers over the landscape well over 5,000 feet tall. lots of them.
This is news to me. Thank you NTSB for this PSA.
I had no idea they were a force to be reckoned with and will share the information! Just saw one 15 miles south of Denver in a construction area - dirt and concrete - but no one flinched at all. Good information.
Hmm, I wonder if any flight simulator programs factor these in. Also wonder if the currently popular Frank Herbert's Dune factors these in.
When I was a youngster one summer afternoon a dust devil blew through a vacant field behind our back yard it came towards and around me and proceeded to the gravel road where it collapsed - when I was in it I wasn't lifted or anything (so weak that one was) but I got a little taste of lower gravity thanks to its lift.
is it qualitatively different from a tornado?
From Wikipedia's Dust Devil article:
[A dust devil (also known regionally as a dirt devil) is a strong, well-formed, and relatively short-lived whirlwind. Its size ranges from small (18 in/half a metre wide and a few yards/metres tall) to large (more than 30 ft/10 m wide and more than half a mile/1 km tall). The primary vertical motion is upward. Dust devils are usually harmless, but can on rare occasions grow large enough to pose a threat to both people and property.
They are comparable to tornadoes in that both are a weather phenomenon involving a vertically oriented rotating column of wind. Most tornadoes are associated with a larger parent circulation, the mesocyclone on the back of a supercell thunderstorm. Dust devils form as a swirling updraft under sunny conditions during fair weather, rarely coming close to the intensity of a tornado.]
These are related to arid conditions, and are common in much of Australia - often called Willey-Willies or similar spelling. Tornadoes come out of significant storms, including "supercells". These can occur in Australia too, but it appears unless someone who knows what it takes to break a large tree sees snapped trees before either council cleans up the mess, or a farmer claims it as firewood, no one realises what occurred. That said, there was an experiment in the Queensland rainforest involving setting of a large amount of conventional explosive to work out what a nuclear explosion during jungle warfare would do. For this trees were "calibrated", to correlate diameter to wind speed required to break them.
Dust devils are clear sky phenomena, and are typically much weaker than tornadoes.
I'm a meteorologist: tornadoes never occur with a clear sky; dust devils almost always do. Dust devils are much weaker. @@Don.Challenger
Music is an unnecessary distraction which brings nothing to the presentation
Kill the music
Nothing wrong with the music IMO
@@earthsystem Agree.
@marclouisb, Adjust your volume slightly or maybe use the closed captions. I liked the music and I don't have the best of ears at my age either.