[HN Gopher] Is Clear Air Turbulence becoming more common?
___________________________________________________________________
Is Clear Air Turbulence becoming more common?
Author : redtriumph
Score : 183 points
Date : 2024-06-28 12:04 UTC (10 hours ago)
(HTM) web link (www.flightradar24.com)
(TXT) w3m dump (www.flightradar24.com)
| thiel wrote:
| > The Prosser report outlines one of the primary reasons for the
| increase in CAT events as the intensification of the jet streams,
| driven by the warming of the planet. As global temperatures rise,
| the temperature gradients between the equator and the poles
| become more pronounced, strengthening the jet streams and
| increasing the likelihood of turbulence .
|
| I was under the impression that, as the poles are MORE affected
| by global warming, the jet stream is becoming weaker? is that
| incorrect?
| badcppdev wrote:
| Got some references?
| mcmcmc wrote:
| They are cited in TFA
|
| https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/202.
| ..
| the_sleaze_ wrote:
| You might be thinking of the Gulf Stream, which is an oceanic
| current and definitively weakening, rather than the jet stream,
| which is an air current.
| quakeguy wrote:
| Exactly, air currents are becoming stronger with warmer
| conditions, but the gulfstream being a water current it is
| expected to become weaker.
| rob74 wrote:
| To muddle things even further, there is a (jet) aircraft
| manufacturer called Gulfstream
| (https://en.wikipedia.org/wiki/Gulfstream_Aerospace).
|
| ...but I fully agree with the rest of your comment.
| HPsquared wrote:
| The jet stream is also driven by temperature differences.
| Same with most wind and weather, it's all various forms of
| heat engine.
|
| (Edit: though apparently the additional moisture in the
| Tropics more than counteracts any reduction in temperature
| difference: see link in Retric's comment)
| wongarsu wrote:
| The jet stream is getting stronger (and its path becomes more
| erratic), but the reasoning provided in the article is
| simplified to the point of being wrong.
|
| The projected warming at the North Pole is much stronger than
| the projected warming at the equator, _decreasing_ the
| temperature gradient. However the moisture carrying capacity
| of air increases exponentially with temperature. Since the
| equator starts warmer, a given change in temperature has a
| bigger effect on moisture carrying capacity. It turns out
| that heating up the equator by one degree Celsius and the
| North Pole by 2 degrees Celsius _increases_ the moisture
| capacity gradient, despite the temperature gradient dropping.
| And that increasing moisture capacity gradient strengthens
| the jet stream.
|
| (at least that's the intuitive reason they were probably
| going for. In reality there are many factors and a good bit
| of "if we simulate it this keeps happening")
| BlueTemplar wrote:
| Thanks for the detailed explanation.
|
| But I also thought that it was the jet stream getting
| _weaker_ that caused it to meander more (which sounds like
| it could increase CAT events ??), which we seem to be
| observing ??
| konschubert wrote:
| That's also what I read:
|
| The poles warm FASTER than the equator. Thus, the global
| temperature gradients are getting smaller.
|
| And as a result, not only does the Jetstream weaken: as a
| result, weather patterns become more stable which leads to
| greater continuous periods of draught or flooding.
| coldtea wrote:
| jetstream != gulf stream
| HPsquared wrote:
| Jet stream is also driven by temperature differences, like
| basically all weather. Heat engines.
| Retric wrote:
| It's a heat engine but more than just temperature changes
| are occurring.
|
| "The new study, by University of Chicago Professor
| Tiffany Shaw and NSF NCAR scientist Osamu Miyawaki, uses
| climate models to show that climate change intensifies
| this density contrast because moisture levels for air
| above the tropics will increase more than above the
| poles."
|
| https://news.ucar.edu/132935/jet-stream-winds-will-
| accelerat....
| HPsquared wrote:
| Fair enough, I guess it's a pretty non-linear system!
| siffin wrote:
| I also think some of the confusion is coming from the use
| of the term 'weakening'. It is true that the primary
| jetstream wind pattern is weakening relative to it's
| stabler state.
|
| That weakening means the jetstream meanders more, with
| more latitudinal movement in its form.
|
| The strength overall of the jetstream wind is weaker when
| it's meandering, but can also be much more intense in
| places.
|
| This says nothing about humidity or energy or pressure,
| just windspeed and direction.
| Retric wrote:
| Your intuition is incorrect. Global warming increases the jet
| stream.
|
| "The new study, by University of Chicago Professor Tiffany
| Shaw and NSF NCAR scientist Osamu Miyawaki, uses climate
| models to show that climate change intensifies this density
| contrast because moisture levels for air above the tropics
| will increase more than above the poles."
|
| https://news.ucar.edu/132935/jet-stream-winds-will-
| accelerat....
| elevation wrote:
| > The poles warm FASTER than the equator
|
| The article cites the Prosser Report which contradicts this
| claim, but I find it hard to understand how this could be
| true for very long. Why wouldn't the atmosphere stabilize as
| gradients diminish?
| photochemsyn wrote:
| Because the earth's rotational axis is not perpendicular to
| incident sunlight (hence dark polar winters). As winter
| sets in, gradients steepen relative to warming equator.
| It's all complicated by the general increase of atmospheric
| water vapor as warming proceeds, which can have different
| effects depending on whether the water vapor is gaseous or
| forms cloud droplets, which reflect sunlight. It's a hard
| physics problem.
| polar_low wrote:
| That is correct, as a longer term trend at least while
| paradoxically, we are also seeing periods of record strength in
| the Jet Streams.
|
| The truth is there are many oscillations and
| teleconnections(themselves being impacted by global warming)
| which influences this temperature gradient on a local/seasonal
| basis. QBO, El Nino/La Nina and mountain torque events to name
| a few can move and shift heat at the tropopause in a short
| period of time and is why we see this wider variance at both
| ends of the spectrum.
| photochemsyn wrote:
| I think the seasonality of the polar environment is a critical
| factor - while warming is expect to decrease the _average_
| equator-to-pole temperature gradient (as all models predict
| faster polar warming than equatorial warming by a large
| margin), winter is still winter as the polar axis is tilted, so
| steep atmospheric gradients are expected over that seasonal
| period.
| nytesky wrote:
| I wonder if this is like an immune system response by mother
| nature, it's attacking the thing that's warming it up i.e. air
| travel? Self correcting systems
| thfuran wrote:
| No, it just turns out that things get more energetic when you
| dump a lot of energy into a system.
| gosub100 wrote:
| couldn't possibly be due to more planes flying more flights.
| piombisallow wrote:
| They haven't actually analyzed reported turbulence, it's just
| a simulation study: "Turbulence data from aircraft could also
| be analyzed, but the time period for which quantitative,
| automated measurements are available is far shorter than the
| 42 years covered here, making trend detection problematic."
| lxgr wrote:
| On the other hand, so far I haven't heard any reports of any
| steel mill or cement plant being destroyed by clear air
| turbulence.
| piombisallow wrote:
| Is there anything global warming can't do?
| triceratops wrote:
| Convince some people it exists.
|
| Whether it's responsible for more CAT - who knows?
| bromuro wrote:
| I prefer to call it climate change, as it is a change of the
| conditions where everyone lives. As such, it is expected to
| affect everyone life.
| osipov wrote:
| Commercial pilot here. Instead of climate change, we should be
| talking about continuous descent profiles (CDPs) that have become
| more common in the past years 5-10 years. These profiles with
| idle engines allow for a smoother, more fuel-efficient descent by
| reducing the need for level-off segments. However, CDPs can
| increase the perception of turbulence during descent. This is
| because aircraft remain at higher altitudes for longer periods,
| where atmospheric instability and wind shear are more pronounced.
| This increased turbulence is not due to climate change but rather
| the result of these optimized descent procedures aimed at
| reducing fuel consumption and minimizing environmental impact.
| vessenes wrote:
| Interesting! I didn't know that descent profiles had changed
| this decade. Now that you mention it, I seem to recall far less
| leveling off than when I was younger, at the very least you've
| incepted the idea into my head now.
|
| Also worth noting that to a passenger, CAT is the worst feeling
| you'll have on most flights -- the "oh shit we're not flying
| anymore" vibe is real bad, and usually when you hit proper air
| again, the sudden jerk feels bad as well.
|
| As someone with like 8 flight hours to my name, I'll say to a
| learning pilot, stalling feels much worse than CAT would, it's
| a different sort of not flying, it's like "oh shit the plane
| forgot how to fly, what now".
| sandywaffles wrote:
| > [Clear Air Turbulence] is particularly common around the
| tropopause, the boundary layer between the troposphere and the
| stratosphere, at altitudes between 7,000 and 12,000 meters
| (23,000 to 39,000 feet) .
|
| Oh, excellent the altitudes that 99% of aircraft fly at,
| unaffecting the ultra rich who fly private jets at
| 40,000k-50,000k+.
| hiatus wrote:
| > Oh, excellent the altitudes that 99% of aircraft fly at,
| unaffecting the ultra rich who fly private jets at
| 40,000k-50,000k+.
|
| I didn't realize private jets fly so high. What's the reason
| for the difference in elevations?
| pc86 wrote:
| Private jets don't really fly at 50k that often but I'm sure
| there are some that can. 40-42k is pretty common though.
| There are a handful of reasons. In no particular order: 1)
| additional separation between recreational private flights
| and scheduled commercial flights 2) higher performance in
| small private jets with typically less than 1k lbs of people
| and cargo 3) winds are generally faster the higher you go so
| you'll usually go about at high as you're able, at least in
| one direction.
|
| Most private jets aren't someone flying a billionaire around
| in a $60M Gulfstream, they're $3M toys being flown around by
| the owner to go to their ski trip.
| nickjj wrote:
| > 3) winds are generally faster the higher you go so you'll
| usually go about at high as you're able, at least in one
| direction.
|
| I recently flew from NYC to Lisbon, Portugal and it was 6.5
| hours there (flying east) and 7.5 hours back (flying west)
| because you go with and against the jet stream.
|
| I wonder if there's a noticeable difference if you fly at a
| lower altitude against the wind. It didn't seem like the
| plane adjusted for that, it cruised at the same altitude
| both ways from what I remember. Both flights used the same
| exact plane type (A330neo).
| pc86 wrote:
| Airlines have dispatch folks that spend a lot of time
| deciding what altitude and route to file. Yes there are
| defaults so it's certainly possible they were busy and
| just filed the same but especially days apart it's likely
| that was the optimal altitude.
|
| They're also looking at fuel economy so even if it takes
| longer if the air is thinner and they burn less fuel they
| may still save money. I imagine there's a certain
| distance where those two lines cross that is probably
| baked into the dispatch software for each plane model.
| FabHK wrote:
| Note also that at higher altitudes the air is less dense,
| but the plane should fly at the same indicated/calibrated
| airspeed to generate the same lift, which means that it
| flies faster (at higher true airspeed).
|
| Basically, with aircraft mass and angle of attack
| unchanged, \rho v^2 must be constant, so smaller density
| \rho -> higher air speed.
| ddoolin wrote:
| Traffic separation. Since they can fly at those altitudes, it
| makes sense to put them there, away from other commercial
| airliners.
| vessenes wrote:
| You got some good answers below, but in addition to those,
| also thinner air = less felt turbulence, so it's more
| comfortable (provided your cabin pressurization is good).
| cinntaile wrote:
| Why do they fly higher? I expected them to fly lower.
| pc86 wrote:
| Ah yes those pesky billionaires putting the tropopause right
| below where all their private jets fly.
| zamadatix wrote:
| You can fly over the tropopause depending how high it is at the
| specific location (can be lower or higher than the numbers
| listed) but, by definition, it'll only be "common" to observe
| turbulence in the range 99% of planes actually fly. I wouldn't
| read too much into that. As some others pointed out the height
| difference probably more due tot he space being faster and
| unused since commercial flights stay to where is more
| efficient.
| FabHK wrote:
| The A320 has a ceiling of 39,100-41,000 ft, the 737 of 37,000
| or 41,000 ft, the 747-8 and A350-900 and A380 of 43,100 ft.
| joohwan wrote:
| Why is this comment being downvoted? Is it not true?
| w14 wrote:
| This does not seem to be borne out by the accident statistics,
| which apparently show no trend in turbulence related accidents.
| (https://www.ntsb.gov/safety/safety-studies/Documents/SS2101....)
|
| I don't know if there are other factors which might be masking a
| rise in incidence of CAT from accident stats?
| cpncrunch wrote:
| Also, they just looked at 2 years, so there could be cherry
| picking. Jet stream is affected by el nino. 1979 was weak el
| nino, 2020 was moderate la nina.
|
| https://ggweather.com/enso/oni.htm
| dclowd9901 wrote:
| Right, and those two years are generationally distant.
| Another question I have is if pilots have a stable mechanism
| (that is, an unchanged objective sensor or something) that
| records the CAT or if it's recorded by pilots, whose
| sensitivity to CAT might differ over time. Didn't mention in
| the article how it's measured.
| throwup238 wrote:
| CATs are recorded in pilot reports using terms like
| "light", "moderate", "severe", and "extreme" which each
| have a definition. I.e. severe is _" Occupants are forced
| violently against seat belts or shoulder straps. Unsecured
| objects are tossed about. Food service and walking are
| impossible."_ I think only severe and extreme turbulence
| need mandatory reports and the lower two levels are a bit
| more subjective ("Food service and walking are difficult")
|
| Newer planes have sensors to measure eddy dissipation rates
| which are an objective measure of turbulence but I don't
| know how widespread those systems are and whether they get
| reported anywhere. They're mostly used for long distance
| transoceanic flights.
| oceanplexian wrote:
| Unsecured objects being tossed around has no real
| meaning, it's about controllability of the aircraft.
|
| I'm a pilot and it's been a while since I went over
| PIREPS but generally severe is rarely used, severe means
| the turbulence is so bad you can no longer control the
| aircraft. What most passengers imagine as severe is
| probably light turbulence. Most of the time it's not even
| reported. As a side note if you're ever on an aircraft
| and not secured at all times, you're making a huge
| mistake.
| withinboredom wrote:
| I watched Cast Away. I always wear my seat belt.
| makestuff wrote:
| Have there been any reports of true severe clear air
| turbulence (where the pilot cannot control the plane) or
| are all of these cases not technically severe because the
| pilots were in control the entire time and it was just a
| bumpy ride?
|
| Another question I have is what do you do in that
| scenario if you can't control it? Just ride it out and
| hope for the best?
| orhmeh09 wrote:
| Is using the bathroom or stretching your legs advisable?
| throwup238 wrote:
| You don't have to live in fear of turbulence when flying,
| just keep your seatbelt on when you're seated. Turbulence
| is fairly rare but it's still a numbers game. The
| probability that you experience it the 99% of the time
| you're seated is much higher than the probability of
| experiencing turbulence while standing, especially since
| pilots proactively turn on the seatbelt sign when
| turbulence is expected.
| robxorb wrote:
| So this could be a trend in pilot reporting rather than
| turbulence?
| eggy wrote:
| Yeah, you should have more concern over human error and Boeing
| than this. But, boy, the more I have flown and the older I am,
| the more I get anxious during turbulence when I fly.
| stouset wrote:
| When was the last time a commercial airliner crashed due to
| turbulence?
| rootusrootus wrote:
| Best I can tell, 1966.
|
| https://en.m.wikipedia.org/wiki/BOAC_Flight_911
| stouset wrote:
| Then I think we can safely worry about other things than
| turbulence :)
| septic-liqueur wrote:
| But you never know... You might be the first one :-)
| dmux wrote:
| >The Boeing 707 jetliner involved disintegrated mid-air
|
| I'm guessing their use of "disintegrated" there is
| supposed to be taken literally as dis-integrated, but
| upon first read, I took it for its more colloquial
| meaning (which to me is closer to pulverized, turn to
| dust, dissolve etc).
| FabHK wrote:
| I relax when it's turbulent. The airframe can handle it [1],
| and at least the pilots are awake.
|
| [1] There's a speed limit for turbulence penetration, chosen
| such that the wings will stall, rather than over-stress the
| airframe.
| eggy wrote:
| Thank you! That's definitely a great way to look at it.
| Complacency and habit breed accidents. Although not the the
| Boeing/mechanical issues. Still worried about the ghost in
| the machine or gremlins!
| vanderZwan wrote:
| Well, assuming that there is indeed more turbulence, that could
| also mean more vigilance against accidents, so that could even
| itself out as safety regulations get stricter than in the past.
| Also, this is mentioned in the conclusions:
|
| > _The report includes an important discussion of the risk to
| unrestrained occupants onboard aircraft, including flight
| attendants - who account for nearly 80% of those seriously
| injured in turbulence-related accidents. Key recommendations in
| the report are intended to help ensure better protections for
| flight attendants_
|
| ... which makes me think of two more possibilities:
|
| 1 - I suspect any careless flight attendant involved in a
| turbulence-related accident would learn their lesson after the
| first time, and take better safety precautions. Perhaps that is
| a stabilizing factor on the number of accidents, since the
| number of flight attendants who need to learn that lesson the
| hard way is probably more a function of how many new flight
| attendants enter the field than it is a product of how much
| turbulence there is.
|
| 2 - Flight attendants under-report minor accidents so they
| don't get into trouble for not respecting safety rules
|
| Of course, this is pure speculation (and assuming that the
| premise of there being more CAT incidents holds up), I'm sure
| the actual document goes into this kind of thing in more detail
| but I don't have the time to dig through 115 papers.
| FabHK wrote:
| > I suspect any careless flight attendant involved in a
| turbulence-related accident would learn their lesson after
| the first time, and take better safety precautions.
|
| They are briefed, no need to learn their lessons after the
| first time. However, it's part of their job to walk around
| the plane (eg to serve food), and so they're less likely to
| be seated than pax. That is the (rather obvious) explanation
| for the fact that they constitute a very high proportion of
| victims, not "careless"ness.
| ImaCake wrote:
| Certainly no detectable trend in that data. But the accident
| frequency is so low that the random variation dominates and
| makes it impossible to distinguish any trend.
|
| What is demonstrably increasing is CAT, due to climate change.
| But considering how infrequent these incidents are we might not
| see a clear increase for several decades.
| vlovich123 wrote:
| Do we really not record turbulence sensor data off the
| airplanes and download it when they're on the ground?
|
| I'm also surprised that these airplanes have on demand
| satellite TV streaming to these airplanes but airlines claim
| that it costs 100k to add that to existing planes. There's
| just no way it's 100k per plane - there must be a cheap way
| to retrofit the data without having it be reliable since it's
| opportunistic. And heck, France is doing it every 4 minutes
| for their planes so why can't Americans figure out how to do
| it.
| TylerE wrote:
| If satelite TV is down, some passengers are mildly annoyed.
| If a regulatory required part of the aircraft is non-
| functional, you're not going flying today.
| vlovich123 wrote:
| You're saying it's impossible to have an optionally
| required feature? If the satellite TV is down some sensor
| data isn't sent. Why would that be cause for grounding
| the plane? You could easily make the regulation an SLA
| like all routes flown must be sending data for 90% of the
| flights on that route for the month and failures to meet
| the SLA are investigated.
|
| Also I've flown a bunch and I've rarely seen the Internet
| link go out except where there's technical limitations
| like crossing the ocean where they can't maintain an
| internet and have to rely on preprogrammed content. Given
| how much money they make from cabin internet, the
| airlines are clearly incentivized to apply pressure to
| keep those things running. I doubt I've seen anyone be
| really annoyed when there's technical difficulties. Most
| people who fall into that category would have made other
| arrangements for entertainment anyway.
| MadnessASAP wrote:
| > Do we really not record turbulence sensor data off the
| airplanes and download it when they're on the ground?
|
| No, accelerometer data is only recorded to the FDR. Which
| has a limited storage window (1-24 hours depending on the
| aircraft) and is slow to download requiring moderately
| specialized equipment and a technician to carry out the
| task. Aircraft downtime and technician hours are both
| expensive and in short supply.
|
| > I'm also surprised that these airplanes have on demand
| satellite TV streaming to these airplanes but airlines
| claim that it costs 100k to add that to existing planes.
| There's just no way it's 100k per plane - there must be a
| cheap way to retrofit the data without having it be
| reliable since it's opportunistic. And heck, France is
| doing it every 4 minutes for their planes so why can't
| Americans figure out how to do it.
|
| _Everything_ on airplanes is expensive. Even cabin
| amenities. You have to prove it won 't start a fire, was
| installed correctly, won't interfere with other equipment,
| won't interfere with the aircrafts structure, and again
| requires technician hours and aircraft downtime.
| dheera wrote:
| > No, accelerometer data is only recorded to the FDR.
| Which has a limited storage window
|
| Apple and Google could fix this my streaming
| accelerometer data to the ground when people are
| connected to in-flight wifi. It is fairly easy to
| identify which phones out of a set are the stationary
| ones.
| throwaway-blaze wrote:
| Well, you have to have paperwork claiming it was
| installed correctly. You don't _have_ to install it
| correctly. See e.g. doors installed so correctly that
| they blow out in flight etc.
| lucianbr wrote:
| What's the point of your comment? Should we just install
| a bunch of accelerometers on planes with faked paperwork
| because some people faked some paperwork somtime?
|
| Sounds like you're upset at Boeing and figured you would
| tell us you're upset on an unrelated thread. Note that it
| doesn't really matter if you are right to be upset at
| Boeing or not. It's still unrelated.
| renewiltord wrote:
| I think his point is that the proof is expensive, not the
| act itself. Reminds me of rivets in composites joined by
| adhesives. The benefit is inspectability. The cost is
| diminished strength.
| vlovich123 wrote:
| I find it hard to believe that the headsets they are
| using for software and hardware meet that level of
| criteria. They're clearly using off-the-shelf parts. Some
| amount of care is called for sure, but 100k to apply a
| software patch or tweak the tech in FDRs which are
| swappable and upgradable? A flight recorder is 10k. You
| can't tell me it costs 90k to install a new one capable
| of sending data over the satellite link in bursts.
| Clearly other countries and airlines with a similar
| safety record and cost of living and salaries are able to
| accomplish the feat.
| mulmen wrote:
| You're solving a human problem with technology. Pilots
| are resistant to data collection because of the proven
| track record of airlines using it against them.
| Unintended consequences are fatal in aviation. Saying "it
| ought to be easy" is an immediately disqualifying
| statement. You should ask instead why it is so expensive.
| Then decide if there's a margin worth eroding.
| londons_explore wrote:
| Meanwhile an accelerometer, microcontroller and a years
| worth of storage for the data probably all could be made
| with $5 worth of parts and a summer intern...
| briandear wrote:
| And multiple years of getting FAA approvals.
| mulmen wrote:
| Comments like this make me glad the FAA requires
| certification for everything.
| supportengineer wrote:
| Almost every single passenger is carrying an accelerometer
| with them. We just have to use that data.
| lxgr wrote:
| Not sure if this data includes accelerometer reports, but
| airplanes actually play an important role in collecting
| data used for weather forecast models:
| https://wmo.int/news/media-centre/covid-19-impacts-
| observing...
|
| Edit: Turns out this already includes turbulence data, and
| this is streamed real-time!
| https://community.wmo.int/en/activity-areas/aircraft-
| based-o...
|
| > France is doing it every 4 minutes for their planes
|
| What are they doing exactly? Are you referring to the
| article?
| benhurmarcel wrote:
| Some aircraft are equipped with a system that records
| parameters in flight, and sends it via 4G when on the
| ground. This is used for preventive maintenance mostly.
| It's a service that's more and more common.
|
| However that data belongs to each airline.
| _moof wrote:
| An increase in the frequency of clear air turbulence doesn't
| necessarily entail an increase in reportable accidents and
| incidents. The NTSB is only notified when a specific set of
| criteria are met. See 49 CFR Part 830 for details. If the
| increase in turbulence is all light to moderate turbulence with
| no serious injuries, there's nothing to report to the NTSB.
| alfalfasprout wrote:
| This deserves to be the top comment. Turbulence accident
| statistics are only going to ever reflect clear air
| turbulence if the aircraft sustained detectable damage or
| passenger(s) sustain serious enough injuries.
| User23 wrote:
| In that case what's the explanation for clear air
| turbulence events having an exactly proportionally lower
| rate of causing damage and injury such that the rate has
| remained flat despite the increase in events? What's making
| turbulence safer?
|
| Edit: this isn't a rhetorical question. I'm very interested
| in any proposed actual mechanism. As someone who is very
| alarmed by turbulence I'd love a reason to believe it's
| getting safer.
| tracerbulletx wrote:
| There's no reason there couldn't be a statistical
| increase in turbulence without a statistical increase in
| accidents if the intensity hasn't crossed a threshold for
| the amount of turbulence todays planes can safely
| sustain.
| largbae wrote:
| Is it possible that the overall increase in flights,
| areas served, and data collection is simply giving us
| more coverage?
| NathanKP wrote:
| As I understand it modern US airlines (Delta in specific)
| employ a meteorology team tasked to predict turbulence
| and they also run complex turbulence tracking systems
| that allow one plane that detects turbulence to
| communicate to a centralized system that allows other
| planes to change altitude or heading to avoid turbulent
| areas when possible.
|
| Therefore both can be true at the same time: turbulence
| events are increasing, but we are also getting better at
| predicting, avoiding, and dealing with these events.
| rdtsc wrote:
| Could be an inverse relationship, too - the more frequently
| they occur the more experience, training and guidance the
| pilot, and the other crew members get to manage it: how to
| control the the airplane, urge passengers to wear seatbelts
| more, etc.
| JoshGG wrote:
| There is a big factor out there that is 'masking a rise in
| incidence of CAT from accident stats'. It's Aerospace Engineers
| and the aviation engineering and safety community. -- Most CAT
| events (seen so far) are survivable by current aircraft
| designs, so you can have an increase in CAT without a spike in
| crashes and other accidents.
| Octabrain wrote:
| I hate flying with passion and get extremely scared when flying
| through turbulences but, there was a journalist in my country,
| that also had experience as a pilot and said once on TV that
| during turbulences, is one of the safest moments in a plane. I
| don't remember the reasons but is there anybody in here with
| knowledge in the field that could confirm/deny this?
| mrWiz wrote:
| Do you recall why they said it was the safest? My first guess
| is because the pilots are paying more attention while flying
| through turbulence.
| MichaelNolan wrote:
| My first guess is that during turbulence everyone has their
| seatbelt on. No one is walking around the cabin. It's only at
| the start of unexpected turbulence that anyone should get
| hurt. Once your seatbelt is on things have to get pretty bad
| to get hurt.
| sandworm101 wrote:
| It is safe because you are flying. Airplanes almost never have
| issues at altitude. Problems occur when closer to the ground.
| Landing/takeoff are the most dangerous times, the transitions
| between flying and not flying.
| FabHK wrote:
| The aviation industry has a perfect record, they've never
| left anyone up there.
| ibejoeb wrote:
| That's just not true. No turbulence is better than turbulence.
|
| That said, experiencing light chop on a modern large airplane
| presents no danger to the airframe or properly secured
| passengers. You really should be strapped in, though,
| especially if you're on a small plane. Wake turbulence, for
| example, actually does present a significant risk to smaller
| aircraft.
| bparsons wrote:
| Commercial airliners are built for extraordinary stress on the
| airframe. You can get a taste of it here:
| https://www.youtube.com/watch?v=--LTYRTKV_A
|
| Other people will correct me if I am wrong, but I believe the
| last time a large commercial airliner was lost to turbulence
| was 1966. https://en.wikipedia.org/wiki/BOAC_Flight_911
| loopdoend wrote:
| > Film footage shows Flight 911 taxiing past the still-
| smoldering wreckage of Flight 402 immediately before taking
| off for the last time.
|
| Wild how far we've come.
| ThinkingGuy wrote:
| Airline pilot/author Patrick Smith has a pretty informative
| article about turbulence on his website:
|
| https://askthepilot.com/questionanswers/turbulence/
| aidenn0 wrote:
| "Fewer than forty feet of altitude change"
|
| A 40 foot drop is pretty scary; by comparison, an NCAA dive
| platform is 33 feet.
| antoniojtorres wrote:
| I agree. It's funny to think of the gap between safety and
| scary when talking about turbulence. Large planes can take
| an absolute beating and be completely fine, but it could
| feel like the end of the world inside.
| oceanplexian wrote:
| A modern airliner is rated to something like 3-4G's
| including the safety factor, probably much more if it's
| not at max takeoff weight. I'm sure you could do a
| Mythbusters-style test but I'd assume most passengers
| would pass out from the negative and positive G forces
| long before the aircraft structurally failed.
| TylerE wrote:
| You'd lose that bet. The wings would fail long before
| people blacked out. They're only required to withstand
| 2.5g positive. Blacking out takes more like 6. We can see
| from various crashes that that sort of G load does in
| fact cause most wings to fail.
|
| Aircraft have to be built light for the sake of
| efficiency (or even, just, being able to get off the
| ground.
|
| There are certainly factors of safety... but not 3x+.
| Probably closer to 1.5.
| dghlsakjg wrote:
| The standard that you must meet to get a pilots license is
| being able to hold your altitude within 100 feet in a 360*
| turn. A 40 foot
|
| He's not saying the drop was 40 feet instantaneously, he's
| saying the turbulence and the subsequent recovery only
| caused a 40 foot deviation from the assigned altitude.
|
| Just for reference, a descent rate on a standard flight is
| pretty normal at 40 feet per second. Some descent profiles
| can double that. The NCAA diver will hit the water at 46
| feet per second.
| MisterTea wrote:
| I feel the same way about flying but a boating enthusiast
| friend bought up an interesting analogy. He asked me if I
| enjoyed boating and I said yes. Then he asked me if it was fun
| when you run over waves bouncing around and I said yes. Then he
| said that is exactly what turbulence is - wakes and waves in
| the air the plane is bouncing on so relax and enjoy the ride.
| Kinda made me feel a little better since I could now visualize
| what is going on but still - eh, Id rather be on terra firma.
| dmux wrote:
| If you've ever sailed, a more apt analogy would be heeling
| over extensively (and potentially capsizing) due to a gale.
| You could be sailing along just fine and then all of a sudden
| you're overpowered. A sail, after all (at least when sailing
| towards the wind) acts just like a wing of a plane.
| bparsons wrote:
| There is also just a huge increase in global air travel, which
| should increase the number of total incidents. The number of
| commercial flights doubled between 2004 and 2019, and is expected
| to continue on that trend for some time.
| nashashmi wrote:
| One day we will research a boson particle that can be fired at
| the air and cause an abrupt polarization allowing for planes to
| travel through with very little air resistance.
| thisisauserid wrote:
| I had never heard of Clear Air Turbulence until last month when I
| finally read the first Culture novel by Ian M. Banks: Consider
| Phlebas.
|
| Now I know that it's the perfect name for a space pirate ship.
| card_zero wrote:
| Chris Foss seemed to think along similar lines when he made
| Gillan's album cover.
|
| https://en.wikipedia.org/wiki/Clear_Air_Turbulence_(album)
| londons_explore wrote:
| If plane wings were hinged (allowing a wing to flop down, but not
| up), then even the worst turbulence couldn't cause negative G in
| the cabin. That would pretty much eliminate injuries.
|
| Obviously the wings need to lock into place for landing, and many
| structural elements of the craft would need to be redesigned.
| animex wrote:
| Could this be internet-enabled flight bias? Now that we have more
| and more WiFi enabled flights, more people posting about it on
| socials...so public awareness grows but as indicated before only
| incident-related stats are being recorded. One can extrapolate if
| incidents including damage or injury are not increasing per
| capita of flights it's probably not a trend.
| lxgr wrote:
| What would prevent people from just posting the same videos and
| tweets once they land?
| ghodith wrote:
| You forget because it happened five hours ago and you are now
| busy getting on with your life?
| jameshart wrote:
| Most of the recent widely publicized CAT injuries have been on
| long distance flights between Europe and South Asia.
|
| One thing that's happened in the past couple of years along that
| air corridor is the squeezing of flight paths out of Ukrainian,
| Russian, Israeli, and Afghan airspace.
|
| Planes taking more circuitous routes, giving them less options to
| avoid weather conditions, much of the flight over hot mountainous
| terrain... could be a contributing factor to increasing incidents
| of dangerous turbulence affecting flights, even if the conditions
| themselves haven't become more common.
| diogenescynic wrote:
| I can't tell if it's just me or something with flights but
| recently when I take flights I get an intense headache that isn't
| similar to other headaches.
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