I don't know if there are other factors which might be masking a rise in incidence of CAT from accident stats?
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.
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.
Flight plans are now algorithmically generated to shave fuel usage.
Because weather forecasts are more accurate, the algorithms write flight plans that take the aircraft closer to storms. This saves fuel while slightly increasing the risk of severe turbulence.
Couple that with the lightweight materials used in modern aircraft, and passengers are likely to experience more frequent moderate to severe turbulence.
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.
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.
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?
If you actually read the short paper you'll find they actually used reanalysis data sampled at a rate of every three hours across 42 years to compute their statistics:
> Global ERA5 reanalysis data (Hersbach et al., 2020) [...] were extracted on the 197 hPa pressure level with 0.25° horizontal resolution at three hourly intervals from 1 January 1979 to 31 December 2020. To allow the computation of CAT diagnostics that require vertical derivatives, fields on the 188 and 206 hPa levels were also extracted. The 21 turbulence diagnostics were then calculated from the extracted reanalysis fields every three hours.
How you go from that to "they just looked at 2 years" is beyond me.
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.
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.
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.
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.
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.
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.
At some point the cost of trying to lie and cut corners becomes worse than the cost of compliance and the airlines and airplane companies will just become good at doing a good job here.
> You should ask instead why it is so expensive.
That is literally my question. I’m highlighting that 100k seems really high to make a system that opportunistically transmits data we are already capturing locally. Rather than a flippant “airplanes should be expensive”, why not ask what is the cheapest retrofit we can do that doesn’t change the safety profile. As I said, this system should not be in the critical path and shouldn’t be a required other than the airplanes should generally be maintaining it to be functional (i.e. the SLA can be 75-90% and still provide tremendous value instead of the 100% SLA target for flight critical components which is what that 100k price tag sounds like).
That this is something highlighted by crash investigators as something that would help in corner cases like incidents over the ocean is just gravy.
Also there's likely 200 accelerometers on board already. Onboard wifi is becoming ubiquitous. Perhaps an app that trades in wifi time for accelerometer time would be good trade-off. And wouldn't require tons of certification.
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?
However that data belongs to each airline.
But anyway, where are you seeing a claim that it costs $100k to record and save turbulence sensor data? I don't see anyone upthread claiming that, and the article doesn't touch on it at all.
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).
> Several booked passengers cancelled their tickets at the last moment to see a ninja demonstration. These passengers, Albert R. Broccoli, Harry Saltzman, Ken Adam, Lewis Gilbert, and Freddie Young, were in Japan scouting locations for the fifth James Bond film, You Only Live Twice (1967).
The James Bond franchise would likely have been quite a bit different had Broccoli died in 1966. Crazy to think he and his colleagues cheated death because they wanted to play tourist a little bit longer than originally scheduled.
[1] There's a speed limit for turbulence penetration, chosen such that the wings will stall, rather than over-stress the airframe.
> 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.
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.