I'm old enough to remember an entirely different airline industry.
You don't see the "same contrails" because you don't "see" the same planes. See, back before I could grow facial hair, jet engines weren't as advanced as they are today. The skies back then were jam packed with jets like the 727, MD-8X, the 737-200, and the most common engine in the skies were the low-bypass turbofan engines such as the Pratt & Whitney JT8D. These engines are less efficient and produce more emissions compared to modern high-bypass turbofans. Low-bypass engines (attached) have a smaller ratio of air bypassing the core to air passing through the core, making them less efficient, the exhaust has significantly higher levels of unburnt hydrocarbons, carbon monoxide, and nitrogen oxides, and tons of small dusty particulates. They mixed with whatever water vapour was in the exhaust and quickly fell to Earth. See how dirty they are??
THAT'S why they were different.
You seem intellectually incapable of comprehending the importance of this change. Compare the 737-MAX's super advanced LEAP-1B jet to the JT8D. It delivers 35,000 pounds of thrust vs the JT8D's 17,000 pounds of thrust ALL WHILE BURNING 20% LESS FUEL per flight hour.
That's HUUUUUUGE.
THAT is why you see more condensation, because the more efficient engines result in SIGNIFICANTLY higher proportions of the fuel being successfully converted to carbon dioxide (CO2) and water (H2O). Thus, for a given amount of fuel, the LEAP-1B would produce far more water as a by-product than older engines, LEADING TO MORE CONTRAILS.
OR it could be a secret CIA global secret program that DEPENDS on people being too stupid to actually ask questions that answer their concerns and you better TURN YOUR YOUTUBE COMMENTS OFF OR ELSE PEOPLE WILL ASK THE WRONG QUESTIONS
I'm very familiar with the analysis of turbo-engines. But here's the problem with your thinking: When fuel is burned, allowing for inefficient combustion, the inefficiency is usually related to full combustion of the carbon. The hydrogen likes to be fully combusted. So, if you are using less fuel, you can't possibly be generating more water, at least for the same thrust level.
There is a simpler reason. Modern aircraft are now flying commonplace at higher altitudes. Where the air has less water vapor, true, but the relative humidity is mostly saturated. So water vapor exhausting into this air cannot remain as vapor and will condense (or crystalize), making a contrail without fail.
I grew up in the town of Bellingham in Washington state. When I was a small child, I would sit out in the back lawn on a sunny and cloudless day, and watch multi-engine jet aircraft fly far overhead, leaving behind white marks across the sky like chalk. What I was watching were test flights of B-52 bombers being built at the Boeing works in Seattle. B-52s fly at 50,000 feet. Flying at much lower altitudes (early jetliners) would only occasionally produce contrails (there was more moisture in the air, but the relative humidity was low).
I'm old enough to remember an entirely different airline industry.
You don't see the "same contrails" because you don't "see" the same planes. See, back before I could grow facial hair, jet engines weren't as advanced as they are today. The skies back then were jam packed with jets like the 727, MD-8X, the 737-200, and the most common engine in the skies were the low-bypass turbofan engines such as the Pratt & Whitney JT8D. These engines are less efficient and produce more emissions compared to modern high-bypass turbofans. Low-bypass engines (attached) have a smaller ratio of air bypassing the core to air passing through the core, making them less efficient, the exhaust has significantly higher levels of unburnt hydrocarbons, carbon monoxide, and nitrogen oxides, and tons of small dusty particulates. They mixed with whatever water vapour was in the exhaust and quickly fell to Earth. See how dirty they are??
THAT'S why they were different.
You seem intellectually incapable of comprehending the importance of this change. Compare the 737-MAX's super advanced LEAP-1B jet to the JT8D. It delivers 35,000 pounds of thrust vs the JT8D's 17,000 pounds of thrust ALL WHILE BURNING 20% LESS FUEL per flight hour.
That's HUUUUUUGE.
THAT is why you see more condensation, because the more efficient engines result in SIGNIFICANTLY higher proportions of the fuel being successfully converted to carbon dioxide (CO2) and water (H2O). Thus, for a given amount of fuel, the LEAP-1B would produce far more water as a by-product than older engines, LEADING TO MORE CONTRAILS.
OR it could be a secret CIA global secret program that DEPENDS on people being too stupid to actually ask questions that answer their concerns and you better TURN YOUR YOUTUBE COMMENTS OFF OR ELSE PEOPLE WILL ASK THE WRONG QUESTIONS
I'm very familiar with the analysis of turbo-engines. But here's the problem with your thinking: When fuel is burned, allowing for inefficient combustion, the inefficiency is usually related to full combustion of the carbon. The hydrogen likes to be fully combusted. So, if you are using less fuel, you can't possibly be generating more water, at least for the same thrust level.
There is a simpler reason. Modern aircraft are now flying commonplace at higher altitudes. Where the air has less water vapor, true, but the relative humidity is mostly saturated. So water vapor exhausting into this air cannot remain as vapor and will condense (or crystalize), making a contrail without fail.
I grew up in the town of Bellingham in Washington state. When I was a small child, I would sit out in the back lawn on a sunny and cloudless day, and watch multi-engine jet aircraft fly far overhead, leaving behind white marks across the sky like chalk. What I was watching were test flights of B-52 bombers being built at the Boeing works in Seattle. B-52s fly at 50,000 feet. Flying at much lower altitudes (early jetliners) would only occasionally produce contrails (there was more moisture in the air, but the relative humidity was low).