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> “On commercial aircraft, anything from a 737 and above you know, 120 people, we have it built in.” No, you don't. Airplanes are designed using a 75kg baselin

> “On commercial aircraft, anything from a 737 and above you know, 120 people, we have it built in.” No, you don't. Airplanes are designed using a 75kg baseline per passenger, including luggage. Now. Let's assume that the engineers felt very generous during their payload estimates, and added a 10% buffer (Spoiler alert: they don't). For a 737, with 170 passengers, that will be 1275kg. Taking the 2022 EASA passenger weight averages from the article, assuming a 50-50 male/female passenger distribution, we get an average passenger weight of 75kg, without luggage. Further assuming an average of 10kg of luggage per passenger, we are now 1700kg overweight, which is almost half a ton over the (generous!) maximum payload estimates. And whilst the Europeans are getting notably heavier in recent times, they are not, by any means the heaviest demographic group on earth. > Overall, a significant weight increase per passenger would be eclipsed by the weight of fuel, cargo and the aircraft itself, said Hilderman. “Fuel is 20 times more than the passenger weight,” he said. No, that's not how it works at all. The fuel weight, and the aircraft weight are what they are for one reason, and one reason only. It is the smallest amount of weight the engineers could get away with to safely and economically transport a certain amount of payload (170 pax) over a chosen distance. Increase that payload by 10%, and you will quickly find out that you need a significantly bigger plane (fuselage, wing, engines, landing gear), and a significantly larger amount of fuel to carry the new payload over the same distance. There are very real safety risks linked to carrying more payload than anticipated (or seriously unbalanced payload distributions) and being outraged about pseudo fat-shaming is not the right answer to this issue.

guenthert 3y ago
Case in point: https://en.wikipedia.org/wiki/2001_Marsh_Harbour_Cessna_402_crash https://en.wikipedia.org/wiki/2001_Marsh_Harbour_Cessna_402_...
- stavros 3y ago
  Wow, I had no idea Aaliyah didn't want to fly and they drugged her and carried her into the plane unconscious. Jeez.
  - willcipriano 3y ago
    I pity the fool.
- throwaway290 3y ago
  There is a difference between +-passenger on a 7 passenger plane and a +-passenger on a 170 passenger plane, so I would not say it is a case in point.
  - justsomehnguy 3y ago
    > +-passenger on a 7 8 / 7 = 1.142 * 170 - 170 = 24p * 75kg = 1800kg
throwaway290 3y ago
I'm confused between people who claim that every airplane is calibrated to exact weight of stuff and the fact that I observe with my own eyes how even airlines known for safety seem to ignore this all the time. Even setting aside passenger weights and carry on, are you saying any time I pay for an overweight piece they literally rebalance everything and add more fuel?
- alphager 3y ago
  Yes, which is why your flight sometimes is delayed until the refueling truck comes around. Pilots calculate the needed fuel depending on weight of the cargo, distance to target, and meteorological conditions on the path. They can only calculate it once they've got the cargo weight (to within a certain degree.)
- orwin 3y ago
  It might depends on the trip and the company, but on Corsair CDG-FDF: yes. No evidence for other flight I took.
- fransje26 3y ago
  > Even setting aside passenger weights and carry on, are you saying any time I pay for an overweight piece they literally rebalance everything and add more fuel? Very much so, yes. After the check-in is closed, the pilots will calculate the required amount of fuel for the flight based on the number of passengers they have, and the weighted hold luggage. And although the checked-in luggage will not be placed in the hold piece by piece to rebalance the plane correctly, they are roughly distributed to not unbalance the plane too much. (Different story for smaller aircrafts, as they have much stricter weight-placement requirements).
  - throwaway290 3y ago
    I guess I stand corrected? Haven't observed it myself. Definitely hear it happen on small planes but Korean Air doesn't really fly them AFAIK.
    - 3y ago
thworp 3y ago
Since you appear to have some insider knowledge: Do you know how airlines deal with different passenger demographics? Does Korean air have adjustment factors for passenger weight averages? Americans 1.4, Brits 1.2, Kenyans 0.9, North Koreans 0.7? Despite how ridiculous it sounds they must do something like this, no?
- fransje26 3y ago
  For your safety, this is more or less what should be done, yes. In practice, they follow AIR OPS regulations set by the FAA or EASA, with fairly up-to date weight studies to estimate the average passenger weight. So for your example, if you use the data average obtained for Europeans, you will be, on average, safe when flying Kenyans and North Koreans. Here is a link to the latest EASA weight study: https://www.easa.europa.eu/en/document-library/research-reports/easa2021c24 https://www.easa.europa.eu/en/document-library/research-repo...
gruez 3y ago
>Airplanes are designed using a 75kg baseline per passenger, including luggage. That seems a bit low. A person with average height (5'8", 172cm) and borderline overweight BMI (25) is already 74kg. Of course, the average American is probably fatter than that, and has luggage as well, which means they're well above the 75kg design limit.
- fransje26 3y ago
  > Commercial airline seating is based on average passenger weight from the 1950s to 1970s, Hilderman said. Since then, people have gotten bigger, but seat pitches have dwindled, he said — “29 inches in some cases, it’s absolutely ridiculous.” >> Of course, the average American is probably fatter than that, and has luggage as well, which means they're well above the 75kg design limit. That's the entire point. When is the point reached where people are getting to fat to safely fly from A to B within the design limits of the airplanes they are flying on. And at which point is time to charge them (and more importantly, allocate) double seats accordingly.
  - soganess 3y ago
    When do we just fix airplane design assumptions to match the real world instead of forcing the real world to comply with the "reasonable" assumptions of the engineers / aircraft firms. I'm almost a full stone lighter than the 75kg assumption, but I'd never walk into an office and just say I'm average, lets just assume that when designing. That is garbage engineering. Your built in assumptions should include projections that cover the expected lifespan of the product, not what is average in the here and now. A simple regression fit would be better than nothing. We should better plan for the extrema of humanity as to not implicitly dehumanize people with averages. That just blows.
- tomjakubowski 3y ago
  Yeah I agree, it seems low. If there is a 75kg per passenger-with-luggage design limit, then it's not just "fat Americans" who are exceeding it. https://www.easa.europa.eu/en/newsroom-and-events/news/easa-review-standard-passenger-weights-2022-shows-no-significant-change https://www.easa.europa.eu/en/newsroom-and-events/news/easa-... > EASA contracted Lufthansa Consulting to conduct a field survey and obtain the average weight of passengers, the weight of hand luggage and the weight of checked luggage at six airports, representing different regions in Europe: ATH (Athens Eleftherios Venizelos, Greece), BRU (Brussels, Belgium), CPH (Copenhagen-Kastrup, Denmark), MXP (Milan Malpensa, Italy), MUC (Munich Franz Josef Strauß, Germany), SOF (Sofia, Bulgaria). > Male passengers have a mean weight of 82.2 kg, which is 14.7 kg more than the average female passenger (67.5 kg). > The average weight of checked luggage, which is always limited by the luggage policies of the airlines, … averaged 16 kg. > (Average carry-on luggage weight, from the study: 7.6kg) For European passengers, men on average brought ~108kg of weight on board, and women ~88kg.
yladiz 3y ago
> No, you don't. Airplanes are designed using a 75kg baseline per passenger, including luggage. Sorry, but I don’t believe you. Can you please cite which airplanes are designed like this? Considering, as alluded to in another comment, the average weight of an American is above 75kg, cabin bags are likely around 5-10kg per, and checked luggage can go up to around 20kg, and you can purchase additional checked bags, what you say seems incredibly unlikely for a large airliner like the 737.

guenthert 3y ago

Case in point: https://en.wikipedia.org/wiki/2001_Marsh_Harbour_Cessna_402_crash https://en.wikipedia.org/wiki/2001_Marsh_Harbour_Cessna_402_...

stavros 3y ago
Wow, I had no idea Aaliyah didn't want to fly and they drugged her and carried her into the plane unconscious. Jeez.
- willcipriano 3y ago
  I pity the fool.
throwaway290 3y ago
There is a difference between +-passenger on a 7 passenger plane and a +-passenger on a 170 passenger plane, so I would not say it is a case in point.
- justsomehnguy 3y ago
  > +-passenger on a 7 8 / 7 = 1.142 * 170 - 170 = 24p * 75kg = 1800kg

throwaway290 3y ago

I'm confused between people who claim that every airplane is calibrated to exact weight of stuff and the fact that I observe with my own eyes how even airlines known for safety seem to ignore this all the time. Even setting aside passenger weights and carry on, are you saying any time I pay for an overweight piece they literally rebalance everything and add more fuel?

alphager 3y ago
Yes, which is why your flight sometimes is delayed until the refueling truck comes around. Pilots calculate the needed fuel depending on weight of the cargo, distance to target, and meteorological conditions on the path. They can only calculate it once they've got the cargo weight (to within a certain degree.)
orwin 3y ago
It might depends on the trip and the company, but on Corsair CDG-FDF: yes. No evidence for other flight I took.
fransje26 3y ago
> Even setting aside passenger weights and carry on, are you saying any time I pay for an overweight piece they literally rebalance everything and add more fuel? Very much so, yes. After the check-in is closed, the pilots will calculate the required amount of fuel for the flight based on the number of passengers they have, and the weighted hold luggage. And although the checked-in luggage will not be placed in the hold piece by piece to rebalance the plane correctly, they are roughly distributed to not unbalance the plane too much. (Different story for smaller aircrafts, as they have much stricter weight-placement requirements).
- throwaway290 3y ago
  I guess I stand corrected? Haven't observed it myself. Definitely hear it happen on small planes but Korean Air doesn't really fly them AFAIK.
  - 3y ago

thworp 3y ago

Since you appear to have some insider knowledge: Do you know how airlines deal with different passenger demographics? Does Korean air have adjustment factors for passenger weight averages? Americans 1.4, Brits 1.2, Kenyans 0.9, North Koreans 0.7? Despite how ridiculous it sounds they must do something like this, no?

fransje26 3y ago
For your safety, this is more or less what should be done, yes. In practice, they follow AIR OPS regulations set by the FAA or EASA, with fairly up-to date weight studies to estimate the average passenger weight. So for your example, if you use the data average obtained for Europeans, you will be, on average, safe when flying Kenyans and North Koreans. Here is a link to the latest EASA weight study: https://www.easa.europa.eu/en/document-library/research-reports/easa2021c24 https://www.easa.europa.eu/en/document-library/research-repo...

gruez 3y ago

>Airplanes are designed using a 75kg baseline per passenger, including luggage. That seems a bit low. A person with average height (5'8", 172cm) and borderline overweight BMI (25) is already 74kg. Of course, the average American is probably fatter than that, and has luggage as well, which means they're well above the 75kg design limit.

fransje26 3y ago
> Commercial airline seating is based on average passenger weight from the 1950s to 1970s, Hilderman said. Since then, people have gotten bigger, but seat pitches have dwindled, he said — “29 inches in some cases, it’s absolutely ridiculous.” >> Of course, the average American is probably fatter than that, and has luggage as well, which means they're well above the 75kg design limit. That's the entire point. When is the point reached where people are getting to fat to safely fly from A to B within the design limits of the airplanes they are flying on. And at which point is time to charge them (and more importantly, allocate) double seats accordingly.
- soganess 3y ago
  When do we just fix airplane design assumptions to match the real world instead of forcing the real world to comply with the "reasonable" assumptions of the engineers / aircraft firms. I'm almost a full stone lighter than the 75kg assumption, but I'd never walk into an office and just say I'm average, lets just assume that when designing. That is garbage engineering. Your built in assumptions should include projections that cover the expected lifespan of the product, not what is average in the here and now. A simple regression fit would be better than nothing. We should better plan for the extrema of humanity as to not implicitly dehumanize people with averages. That just blows.
tomjakubowski 3y ago
Yeah I agree, it seems low. If there is a 75kg per passenger-with-luggage design limit, then it's not just "fat Americans" who are exceeding it. https://www.easa.europa.eu/en/newsroom-and-events/news/easa-review-standard-passenger-weights-2022-shows-no-significant-change https://www.easa.europa.eu/en/newsroom-and-events/news/easa-... > EASA contracted Lufthansa Consulting to conduct a field survey and obtain the average weight of passengers, the weight of hand luggage and the weight of checked luggage at six airports, representing different regions in Europe: ATH (Athens Eleftherios Venizelos, Greece), BRU (Brussels, Belgium), CPH (Copenhagen-Kastrup, Denmark), MXP (Milan Malpensa, Italy), MUC (Munich Franz Josef Strauß, Germany), SOF (Sofia, Bulgaria). > Male passengers have a mean weight of 82.2 kg, which is 14.7 kg more than the average female passenger (67.5 kg). > The average weight of checked luggage, which is always limited by the luggage policies of the airlines, … averaged 16 kg. > (Average carry-on luggage weight, from the study: 7.6kg) For European passengers, men on average brought ~108kg of weight on board, and women ~88kg.

yladiz 3y ago

> No, you don't. Airplanes are designed using a 75kg baseline per passenger, including luggage. Sorry, but I don’t believe you. Can you please cite which airplanes are designed like this? Considering, as alluded to in another comment, the average weight of an American is above 75kg, cabin bags are likely around 5-10kg per, and checked luggage can go up to around 20kg, and you can purchase additional checked bags, what you say seems incredibly unlikely for a large airliner like the 737.