7 ms·

I haven't thought that air travel can be made significantly better but I think 5 years ago or so I flew the dream liner for the first time and it was so much qu

I haven't thought that air travel can be made significantly better but I think 5 years ago or so I flew the dream liner for the first time and it was so much quieter and so much better because of it. Anyone knows how long a airplane has to fly to be written of?

adgjlsfhk1 2y ago
Roughly 25 years. The other thing that you probably didn't notice directly but made you feel better is the better pressurization. Newer planes tend to keep higher pressures (since carbon fiber is ridiculously strong), which helps prevent some of the general discomfort of flying.
- simonjgreen 2y ago
  The 787 and the A350 are both a delight to fly long haul
  - s1artibartfast 2y ago
    I still prefer A380 when I can get one. The extra space is amazing.
    - gruez 2y ago
      Isn't that determined by seat pitch, which in turn is arbitrarily configurable by the airline? What does the model have to do with it?
      - skissane 2y ago
        Given how huge the A380 is, it is more likely to fly less than completely full, which increases the odds that you'll have vacant seat(s) next to you in economy class. Also, if you want to go for a walk, the distance you are allowed to walk is a lot further.
        kijiki 2y ago
        > Given how huge the A380 is, it is more likely to fly less than completely full That is quite nice as a passenger, but also a big part of why they're no longer made, and why most airlines are phasing them out...
      - deleted 2y ago
        [deleted]
      - apelapan 2y ago
        The A380 has higher ceilings than other planes. Doesn't help the knees but makes it feel a lot more airy.
    - johnwalkr 2y ago
      One thing I dislike about flying a full-ish A380 is the length of time for meal service. It can be over 1 hour that you have to sit with your tray table occupied and seat upright, before your tray gets picked up. If you want to use a laptop or sleep, it feels like forever.
- dredmorbius 2y ago
  NB, for any budding bathynauts: carbon fibre is strong under tension, which is precisely the use-case for higher-than-ambient-pressure vessels such as air- and space-craft. It's far less comparatively strong under compression, which seems to have been the principle failure mode of the now-permanently-submerged Titan. The failure modes of explosive vs. implosive failure are also relevant. High-pressure implosions tend to collapse the entire hull, whilst so far as I understand, explosive failure, particularly at the relatively low pressure differentials of air and space flight, tend to be localised, and the fibre-reinforced nature of composite materials should reduce damage to the neighbourhood of the initial failure point in many cases. Implosive failure needn't actually penetrate the hull so much as crease it, a mode which CF handles poorly respective to the application.
  - Terr_ 2y ago
    I think a lot of people have a misconception that keeping pressure in is just as hard as keeping pressure out, while in some ways, it's probably easier to make a space station (keep 1 ATM in) than to make a submarine (keep 500 ATM out.) Hence sci-fi horrors is like getting sucked out into space through a pinhole.
    - adgjlsfhk1 2y ago
      yeah, this is really one of my pet peeves. Lots of people like to pretend that holding a vacuum is really hard, but if all you need is a gross vacuum, it's only about as hard as going down 40 ft into the water.
      - eastbound 2y ago
        Other misconception: That we immediately die in space. You can probably survive a minute or two.
    - euroderf 2y ago
      If a micrometeorite (or other space detritus) puts a pinhole in a wall in the space station, can you plug it by covering it with your finger, without necessarily losing the finger ?
- ChrisMarshallNY 2y ago
  I never got the chance to fly in a Dreamliner, but I have been told that its air is also more humid than standard jets (because of the carbon-fiber construction, I think, so metal oxidation isn’t an issue).
  - adgjlsfhk1 2y ago
    > because of the carbon-fiber construction yes > so metal oxidation isn’t an issue no. It's not rust, but that higher pressure air can hold more water at the same relative humidity. The higher pressure air is achievable because carbon fiber has higher tensile strength per weight.
    - ChrisMarshallNY 2y ago
      That makes more sense. Thanks!
    - nemetroid 2y ago
      > higher pressure air can hold more water at the same relative humidity The 787 and A350 cabins have higher relative humidity. > no. It's not rust, Citation needed. Corrosion resistance is one of the most advertised benefits of the composite materials in those aircraft[1][2]. 1: http://www.lb.boeing.com/commercial/aeromagazine/articles/qtr_4_06/article_04_2.html http://www.lb.boeing.com/commercial/aeromagazine/articles/qt... 2: https://skybrary.aero/sites/default/files/bookshelf/3851.pdf https://skybrary.aero/sites/default/files/bookshelf/3851.pdf
  - wkat4242 2y ago
    Nice, then finally I won't get nosebleeds on long flights <3
    - ChrisMarshallNY 2y ago
      Also, I get headaches on planes. The 10,000-foot altitude air pressure does it.
- bobmcnamara 2y ago
  These are Boeings we're talking about.
WalterBright 2y ago
62,000 flight hours
- dredmorbius 2y ago
  Flight hours or flight cycles? I suspect that pressure hull and wing spars experience the greatest loading and fatigue, and may be differentially influenced by overall flight time and takeoff/landing cycles.
  - WalterBright 2y ago
    Hours. I remember the incident with an Aloha Airlines 737 where fatigue damage caused the failure of part of the structure. Those airplanes were only used for very short hops, hence a high ratio of cycles/hours. While they were within the 62,000 hour limit, the cycles were very high and were not anticipated in the fatigue calculations. The criteria might have changed since that incident. Maintenance schedules are based on hours. Pilot experience is also logged as hours.
    - mattmaroon 2y ago
      It's actually both, specifically because of that incident. (Pretty much any time a commercial jetliner crashes, a rule changes, and it's been that way for decades.) There's an hour number and a cycle number for many maintenances, and whichever comes first triggers the maintenance. Hulls, however are rated for a max number of cycles due to fatigue caused by the pressurization/depressurization and that's the part of the plane that cannot be replaced. So the plane usually gets junked or shipped to a developing world airline due to cycles.
    - MobileVet 2y ago
      This is my only claim to fame, the pilot is my mom’s cousin. Super nice guy. Hearing him tell the story first hand was pretty incredible. He saw sky, so knew he had a hole… but had no idea it was so extensive until they landed and he walked back there. Can you imagine the phone footage we would have had from that it if it happened today?!
sitharus 2y ago
I recently flew on an A320neo and then an A320ceo a few days later, both in similar cabin positions and the difference was incredible. On the neo I could easily talk to the cabin crew without raising my voice, the ceo felt like I was having to shout. I’m flying on an A380 in a few days, that will be interesting experience after only flying long haul on 777s in the past few years
- EdwardDiego 2y ago
  Love the A380, just try to avoid Lufthansa's one, they tend to be the worst at seat space in economy and service. Emirates is my fav.
bamboozled 2y ago
Because of what ?
- t0mas88 2y ago
  Higher air pressure (lower cabin altitude) and higher humidity. Both make passengers feel better.
  - bombcar 2y ago
    You basically subject yourself to altitude sickness every time you fly. It's actually kind of ridiculous how "unpleasant" flights are, but since they're rare enough we just accept it.
    - tekla 2y ago
      Not really, while its possible to get altitude sickness below 8k ft, its very very rare. Pretty much every aircraft pressurizes to below 8k feet because of regulations.
      - bombcar 2y ago
        Perhaps not technically altitude sickness, but the weariness everyone feels when they get to Denver for awhile.
mattmaroon 2y ago
I assume you mean written off, and the answer is it's generally not about how long, it's about how many "cycles". Plane maintenance is usually required on a schedule based on how many flight hours or cycles, and it's usually the cycles they hit first. A cycle is a pressurization and de-pressurization of the cabin. This is what eventually kills a jetliner, the hull will fracture from the stress. The engines are designed to rebuilt/replaced periodically. The hull cannot be reasonably repaired once damaged. Airliners are required to do different checks at different stages, and the big one costs millions of dollars and requires them to basically disassemble and rebuild the plane. They even may have to remove the paint to check the hull for issues. Industrialized nations generally will only do this a couple times before the cost is more than the jet is worth (I think this is generally around 20,000 cycles, depending on the plane) then they sell them to a third world airline who doesn't have as strict a regulatory scheme. Even then, they generally live on for quite awhile, our regulatory scheme is designed to get as close to zero risk as possible, not to be economical, and it's hard to argue with the results. This is one of many reasons why there are an order of magnitude more crashes in the developing world, though even still safety is high relative to almost anything other than first world commercial airlines.
- zikduruqe 2y ago
  "The recently imposed smoking ban on many commercial flights has had one distinctly unhealthy side effect -- it snuffed out the most popular method mechanics used to spot cracks in aircraft fuselages. ... mechanics could count on tell-tale build-up of nicotine around cracks as air escaped from the passenger cabin when the plane pressurized after lift-off." https://www.upi.com/Archives/1988/05/27/The-recently-imposed-smoking-ban-on-many-commercial-flights/6624580708800/ https://www.upi.com/Archives/1988/05/27/The-recently-imposed...
lostlogin 2y ago
> haven't thought that air travel can be made significantly better I wonder if it could be made significantly worse. Leg room has been reduced overtime as far as I can tell. I’m 198cm, and it’s actually hell. I probably need to just pay more and go nearer the front, however this would only solve the legroom problem. The seats are too low and aren’t even close to supporting someone tall. I’m in NZ so everything is far away, and 18+ hour flights are actually awful.
Terr_ 2y ago
When it comes cases of travel feeling worse, I find it's always worth making sure you adjust the cost for inflation. Sure, we'd expect certain engineering things to get cheaper over time, but you can also see why some luxury touches got phased--or rather priced--out. :p
wkat4242 2y ago
It's not just Boeing. The Embraer E195 E2 is also way more comfy than your 737 despite being much smaller

adgjlsfhk1 2y ago

Roughly 25 years. The other thing that you probably didn't notice directly but made you feel better is the better pressurization. Newer planes tend to keep higher pressures (since carbon fiber is ridiculously strong), which helps prevent some of the general discomfort of flying.

simonjgreen 2y ago
The 787 and the A350 are both a delight to fly long haul
- s1artibartfast 2y ago
  I still prefer A380 when I can get one. The extra space is amazing.
  - gruez 2y ago
    Isn't that determined by seat pitch, which in turn is arbitrarily configurable by the airline? What does the model have to do with it?
    - skissane 2y ago
      Given how huge the A380 is, it is more likely to fly less than completely full, which increases the odds that you'll have vacant seat(s) next to you in economy class. Also, if you want to go for a walk, the distance you are allowed to walk is a lot further.
      - kijiki 2y ago
        > Given how huge the A380 is, it is more likely to fly less than completely full That is quite nice as a passenger, but also a big part of why they're no longer made, and why most airlines are phasing them out...
    - deleted 2y ago
      [deleted]
    - apelapan 2y ago
      The A380 has higher ceilings than other planes. Doesn't help the knees but makes it feel a lot more airy.
  - johnwalkr 2y ago
    One thing I dislike about flying a full-ish A380 is the length of time for meal service. It can be over 1 hour that you have to sit with your tray table occupied and seat upright, before your tray gets picked up. If you want to use a laptop or sleep, it feels like forever.
dredmorbius 2y ago
NB, for any budding bathynauts: carbon fibre is strong under tension, which is precisely the use-case for higher-than-ambient-pressure vessels such as air- and space-craft. It's far less comparatively strong under compression, which seems to have been the principle failure mode of the now-permanently-submerged Titan. The failure modes of explosive vs. implosive failure are also relevant. High-pressure implosions tend to collapse the entire hull, whilst so far as I understand, explosive failure, particularly at the relatively low pressure differentials of air and space flight, tend to be localised, and the fibre-reinforced nature of composite materials should reduce damage to the neighbourhood of the initial failure point in many cases. Implosive failure needn't actually penetrate the hull so much as crease it, a mode which CF handles poorly respective to the application.
- Terr_ 2y ago
  I think a lot of people have a misconception that keeping pressure in is just as hard as keeping pressure out, while in some ways, it's probably easier to make a space station (keep 1 ATM in) than to make a submarine (keep 500 ATM out.) Hence sci-fi horrors is like getting sucked out into space through a pinhole.
  - adgjlsfhk1 2y ago
    yeah, this is really one of my pet peeves. Lots of people like to pretend that holding a vacuum is really hard, but if all you need is a gross vacuum, it's only about as hard as going down 40 ft into the water.
    - eastbound 2y ago
      Other misconception: That we immediately die in space. You can probably survive a minute or two.
  - euroderf 2y ago
    If a micrometeorite (or other space detritus) puts a pinhole in a wall in the space station, can you plug it by covering it with your finger, without necessarily losing the finger ?
ChrisMarshallNY 2y ago
I never got the chance to fly in a Dreamliner, but I have been told that its air is also more humid than standard jets (because of the carbon-fiber construction, I think, so metal oxidation isn’t an issue).
- adgjlsfhk1 2y ago
  > because of the carbon-fiber construction yes > so metal oxidation isn’t an issue no. It's not rust, but that higher pressure air can hold more water at the same relative humidity. The higher pressure air is achievable because carbon fiber has higher tensile strength per weight.
  - ChrisMarshallNY 2y ago
    That makes more sense. Thanks!
  - nemetroid 2y ago
    > higher pressure air can hold more water at the same relative humidity The 787 and A350 cabins have higher relative humidity. > no. It's not rust, Citation needed. Corrosion resistance is one of the most advertised benefits of the composite materials in those aircraft[1][2]. 1: http://www.lb.boeing.com/commercial/aeromagazine/articles/qtr_4_06/article_04_2.html http://www.lb.boeing.com/commercial/aeromagazine/articles/qt... 2: https://skybrary.aero/sites/default/files/bookshelf/3851.pdf https://skybrary.aero/sites/default/files/bookshelf/3851.pdf
- wkat4242 2y ago
  Nice, then finally I won't get nosebleeds on long flights <3
  - ChrisMarshallNY 2y ago
    Also, I get headaches on planes. The 10,000-foot altitude air pressure does it.
bobmcnamara 2y ago
These are Boeings we're talking about.

WalterBright 2y ago

62,000 flight hours

dredmorbius 2y ago
Flight hours or flight cycles? I suspect that pressure hull and wing spars experience the greatest loading and fatigue, and may be differentially influenced by overall flight time and takeoff/landing cycles.
- WalterBright 2y ago
  Hours. I remember the incident with an Aloha Airlines 737 where fatigue damage caused the failure of part of the structure. Those airplanes were only used for very short hops, hence a high ratio of cycles/hours. While they were within the 62,000 hour limit, the cycles were very high and were not anticipated in the fatigue calculations. The criteria might have changed since that incident. Maintenance schedules are based on hours. Pilot experience is also logged as hours.
  - mattmaroon 2y ago
    It's actually both, specifically because of that incident. (Pretty much any time a commercial jetliner crashes, a rule changes, and it's been that way for decades.) There's an hour number and a cycle number for many maintenances, and whichever comes first triggers the maintenance. Hulls, however are rated for a max number of cycles due to fatigue caused by the pressurization/depressurization and that's the part of the plane that cannot be replaced. So the plane usually gets junked or shipped to a developing world airline due to cycles.
  - MobileVet 2y ago
    This is my only claim to fame, the pilot is my mom’s cousin. Super nice guy. Hearing him tell the story first hand was pretty incredible. He saw sky, so knew he had a hole… but had no idea it was so extensive until they landed and he walked back there. Can you imagine the phone footage we would have had from that it if it happened today?!

sitharus 2y ago

I recently flew on an A320neo and then an A320ceo a few days later, both in similar cabin positions and the difference was incredible. On the neo I could easily talk to the cabin crew without raising my voice, the ceo felt like I was having to shout. I’m flying on an A380 in a few days, that will be interesting experience after only flying long haul on 777s in the past few years

EdwardDiego 2y ago
Love the A380, just try to avoid Lufthansa's one, they tend to be the worst at seat space in economy and service. Emirates is my fav.

bamboozled 2y ago

Because of what ?

t0mas88 2y ago
Higher air pressure (lower cabin altitude) and higher humidity. Both make passengers feel better.
- bombcar 2y ago
  You basically subject yourself to altitude sickness every time you fly. It's actually kind of ridiculous how "unpleasant" flights are, but since they're rare enough we just accept it.
  - tekla 2y ago
    Not really, while its possible to get altitude sickness below 8k ft, its very very rare. Pretty much every aircraft pressurizes to below 8k feet because of regulations.
    - bombcar 2y ago
      Perhaps not technically altitude sickness, but the weariness everyone feels when they get to Denver for awhile.

mattmaroon 2y ago

I assume you mean written off, and the answer is it's generally not about how long, it's about how many "cycles". Plane maintenance is usually required on a schedule based on how many flight hours or cycles, and it's usually the cycles they hit first. A cycle is a pressurization and de-pressurization of the cabin. This is what eventually kills a jetliner, the hull will fracture from the stress. The engines are designed to rebuilt/replaced periodically. The hull cannot be reasonably repaired once damaged. Airliners are required to do different checks at different stages, and the big one costs millions of dollars and requires them to basically disassemble and rebuild the plane. They even may have to remove the paint to check the hull for issues. Industrialized nations generally will only do this a couple times before the cost is more than the jet is worth (I think this is generally around 20,000 cycles, depending on the plane) then they sell them to a third world airline who doesn't have as strict a regulatory scheme. Even then, they generally live on for quite awhile, our regulatory scheme is designed to get as close to zero risk as possible, not to be economical, and it's hard to argue with the results. This is one of many reasons why there are an order of magnitude more crashes in the developing world, though even still safety is high relative to almost anything other than first world commercial airlines.

zikduruqe 2y ago
"The recently imposed smoking ban on many commercial flights has had one distinctly unhealthy side effect -- it snuffed out the most popular method mechanics used to spot cracks in aircraft fuselages. ... mechanics could count on tell-tale build-up of nicotine around cracks as air escaped from the passenger cabin when the plane pressurized after lift-off." https://www.upi.com/Archives/1988/05/27/The-recently-imposed-smoking-ban-on-many-commercial-flights/6624580708800/ https://www.upi.com/Archives/1988/05/27/The-recently-imposed...

lostlogin 2y ago

> haven't thought that air travel can be made significantly better I wonder if it could be made significantly worse. Leg room has been reduced overtime as far as I can tell. I’m 198cm, and it’s actually hell. I probably need to just pay more and go nearer the front, however this would only solve the legroom problem. The seats are too low and aren’t even close to supporting someone tall. I’m in NZ so everything is far away, and 18+ hour flights are actually awful.

Terr_ 2y ago

When it comes cases of travel feeling worse, I find it's always worth making sure you adjust the cost for inflation. Sure, we'd expect certain engineering things to get cheaper over time, but you can also see why some luxury touches got phased--or rather priced--out. :p

wkat4242 2y ago

It's not just Boeing. The Embraer E195 E2 is also way more comfy than your 737 despite being much smaller